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Abstract all the accesses to cop_arybase (apart from ByteLoader)
[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 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                          &cur_env, 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                          PL_top_env, 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
136 struct cop {
137     BASEOP
138     char *      cop_label;      /* label for this construct */
139 #ifdef USE_ITHREADS
140     char *      cop_stashpv;    /* package line was compiled in */
141     char *      cop_file;       /* file name the following line # is from */
142 #else
143     HV *        cop_stash;      /* package line was compiled in */
144     GV *        cop_filegv;     /* file the following line # is from */
145 #endif
146     U32         cop_seq;        /* parse sequence number */
147     I32         cop_arybase;    /* array base this line was compiled with */
148     line_t      cop_line;       /* line # of this command */
149     SV *        cop_warnings;   /* lexical warnings bitmask */
150     SV *        cop_io;         /* lexical IO defaults */
151     /* compile time state of %^H.  See the comment in op.c for how this is
152        used to recreate a hash to return from caller.  */
153     struct refcounted_he * cop_hints;
154 };
155
156 #ifdef USE_ITHREADS
157 #  define CopFILE(c)            ((c)->cop_file)
158 #  define CopFILEGV(c)          (CopFILE(c) \
159                                  ? gv_fetchfile(CopFILE(c)) : NULL)
160                                  
161 #  ifdef NETWARE
162 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
163 #  else
164 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
165 #  endif
166
167 #  define CopFILESV(c)          (CopFILE(c) \
168                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
169 #  define CopFILEAV(c)          (CopFILE(c) \
170                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
171 #  ifdef DEBUGGING
172 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
173                                    GvAV(gv_fetchfile(CopFILE(c))))
174 #  else
175 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
176 #  endif
177 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
178
179 #  ifdef NETWARE
180 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
181 #  else
182 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
183 #  endif
184
185 #  define CopSTASH(c)           (CopSTASHPV(c) \
186                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
187 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
188 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
189 #  ifdef NETWARE
190 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
191 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
192 #  else
193 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
194 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
195 #  endif
196 #else
197 #  define CopFILEGV(c)          ((c)->cop_filegv)
198 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
199 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
200 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
201 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
202 #  ifdef DEBUGGING
203 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
204 #  else
205 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
206 # endif
207 #  define CopFILE(c)            (CopFILESV(c) ? SvPVX(CopFILESV(c)) : NULL)
208 #  define CopSTASH(c)           ((c)->cop_stash)
209 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
210 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
211    /* cop_stash is not refcounted */
212 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
213 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
214 #  define CopSTASH_free(c)      
215 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
216
217 #endif /* USE_ITHREADS */
218
219 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
220 #define CopLINE(c)              ((c)->cop_line)
221 #define CopLINE_inc(c)          (++CopLINE(c))
222 #define CopLINE_dec(c)          (--CopLINE(c))
223 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
224
225 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
226 #ifdef MACOS_TRADITIONAL
227 #  define OutCopFILE(c) MacPerl_MPWFileName(CopFILE(c))
228 #else
229 #  define OutCopFILE(c) CopFILE(c)
230 #endif
231
232 /* CopARYBASE is likely to be removed soon.  */
233 #define CopARYBASE(c)           ((c)->cop_arybase)
234 #define CopARYBASE_get(c)       ((c)->cop_arybase + 0)
235 #define CopARYBASE_set(c, b)    STMT_START { (c)->cop_arybase = (b); } STMT_END
236
237 /*
238  * Here we have some enormously heavy (or at least ponderous) wizardry.
239  */
240
241 /* subroutine context */
242 struct block_sub {
243     CV *        cv;
244     GV *        gv;
245     GV *        dfoutgv;
246     AV *        savearray;
247     AV *        argarray;
248     I32         olddepth;
249     U8          hasargs;
250     U8          lval;           /* XXX merge lval and hasargs? */
251     PAD         *oldcomppad;
252     OP *        retop;  /* op to execute on exit from sub */
253 };
254
255 /* base for the next two macros. Don't use directly.
256  * Note that the refcnt of the cv is incremented twice;  The CX one is
257  * decremented by LEAVESUB, the other by LEAVE. */
258
259 #define PUSHSUB_BASE(cx)                                                \
260         cx->blk_sub.cv = cv;                                            \
261         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
262         cx->blk_sub.hasargs = hasargs;                                  \
263         cx->blk_sub.retop = NULL;                                       \
264         if (!CvDEPTH(cv)) {                                             \
265             SvREFCNT_inc_void(cv);                                      \
266             SvREFCNT_inc_void(cv);                                      \
267             SAVEFREESV(cv);                                             \
268         }
269
270
271 #define PUSHSUB(cx)                                                     \
272         PUSHSUB_BASE(cx)                                                \
273         cx->blk_sub.lval = PL_op->op_private &                          \
274                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
275
276 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
277 #define PUSHSUB_DB(cx)                                                  \
278         PUSHSUB_BASE(cx)                                                \
279         cx->blk_sub.lval = 0;
280
281
282 #define PUSHFORMAT(cx)                                                  \
283         cx->blk_sub.cv = cv;                                            \
284         cx->blk_sub.gv = gv;                                            \
285         cx->blk_sub.retop = NULL;                                       \
286         cx->blk_sub.hasargs = 0;                                        \
287         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
288         SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
289
290 #define POP_SAVEARRAY()                                         \
291     STMT_START {                                                        \
292         SvREFCNT_dec(GvAV(PL_defgv));                                   \
293         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
294     } STMT_END
295
296 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
297  * leave any (a fast av_clear(ary), basically) */
298 #define CLEAR_ARGARRAY(ary) \
299     STMT_START {                                                        \
300         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
301         SvPV_set(ary, (char*)AvALLOC(ary));                             \
302         AvFILLp(ary) = -1;                                              \
303     } STMT_END
304
305 #define POPSUB(cx,sv)                                                   \
306     STMT_START {                                                        \
307         if (cx->blk_sub.hasargs) {                                      \
308             POP_SAVEARRAY();                                            \
309             /* abandon @_ if it got reified */                          \
310             if (AvREAL(cx->blk_sub.argarray)) {                         \
311                 SSize_t fill = AvFILLp(cx->blk_sub.argarray);           \
312                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
313                 cx->blk_sub.argarray = newAV();                         \
314                 av_extend(cx->blk_sub.argarray, fill);                  \
315                 AvREIFY_only(cx->blk_sub.argarray);                     \
316                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
317             }                                                           \
318             else {                                                      \
319                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
320             }                                                           \
321         }                                                               \
322         sv = (SV*)cx->blk_sub.cv;                                       \
323         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
324             sv = NULL;                                          \
325     } STMT_END
326
327 #define LEAVESUB(sv)                                                    \
328     STMT_START {                                                        \
329         if (sv)                                                         \
330             SvREFCNT_dec(sv);                                           \
331     } STMT_END
332
333 #define POPFORMAT(cx)                                                   \
334         setdefout(cx->blk_sub.dfoutgv);                                 \
335         SvREFCNT_dec(cx->blk_sub.dfoutgv);
336
337 /* eval context */
338 struct block_eval {
339     I32         old_in_eval;
340     I32         old_op_type;
341     SV *        old_namesv;
342     OP *        old_eval_root;
343     SV *        cur_text;
344     CV *        cv;
345     OP *        retop;  /* op to execute on exit from eval */
346     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
347 };
348
349 #define PUSHEVAL(cx,n,fgv)                                              \
350     STMT_START {                                                        \
351         cx->blk_eval.old_in_eval = PL_in_eval;                          \
352         cx->blk_eval.old_op_type = PL_op->op_type;                      \
353         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
354         cx->blk_eval.old_eval_root = PL_eval_root;                      \
355         cx->blk_eval.cur_text = PL_linestr;                             \
356         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
357         cx->blk_eval.retop = NULL;                                      \
358         cx->blk_eval.cur_top_env = PL_top_env;                          \
359     } STMT_END
360
361 #define POPEVAL(cx)                                                     \
362     STMT_START {                                                        \
363         PL_in_eval = cx->blk_eval.old_in_eval;                          \
364         optype = cx->blk_eval.old_op_type;                              \
365         PL_eval_root = cx->blk_eval.old_eval_root;                      \
366         if (cx->blk_eval.old_namesv)                                    \
367             sv_2mortal(cx->blk_eval.old_namesv);                        \
368     } STMT_END
369
370 /* loop context */
371 struct block_loop {
372     char *      label;
373     I32         resetsp;
374     OP *        redo_op;
375     OP *        next_op;
376     OP *        last_op;
377 #ifdef USE_ITHREADS
378     void *      iterdata;
379     PAD         *oldcomppad;
380 #else
381     SV **       itervar;
382 #endif
383     SV *        itersave;
384     SV *        iterlval;
385     AV *        iterary;
386     IV          iterix;
387     IV          itermax;
388 };
389
390 #ifdef USE_ITHREADS
391 #  define CxITERVAR(c)                                                  \
392         ((c)->blk_loop.iterdata                                         \
393          ? (CxPADLOOP(cx)                                               \
394             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
395                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
396             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
397          : (SV**)NULL)
398 #  define CX_ITERDATA_SET(cx,idata)                                     \
399         CX_CURPAD_SAVE(cx->blk_loop);                                   \
400         if ((cx->blk_loop.iterdata = (idata)))                          \
401             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
402         else                                                            \
403             cx->blk_loop.itersave = NULL;
404 #else
405 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
406 #  define CX_ITERDATA_SET(cx,ivar)                                      \
407         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
408             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
409         else                                                            \
410             cx->blk_loop.itersave = NULL;
411 #endif
412
413 #define PUSHLOOP(cx, dat, s)                                            \
414         cx->blk_loop.label = PL_curcop->cop_label;                      \
415         cx->blk_loop.resetsp = s - PL_stack_base;                       \
416         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
417         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
418         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
419         cx->blk_loop.iterlval = NULL;                                   \
420         cx->blk_loop.iterary = NULL;                                    \
421         cx->blk_loop.iterix = -1;                                       \
422         CX_ITERDATA_SET(cx,dat);
423
424 #define POPLOOP(cx)                                                     \
425         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
426         if (CxITERVAR(cx)) {                                            \
427             if (SvPADMY(cx->blk_loop.itersave)) {                       \
428                 SV ** const s_v_p = CxITERVAR(cx);                      \
429                 sv_2mortal(*s_v_p);                                     \
430                 *s_v_p = cx->blk_loop.itersave;                         \
431             }                                                           \
432             else {                                                      \
433                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
434             }                                                           \
435         }                                                               \
436         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
437             SvREFCNT_dec(cx->blk_loop.iterary);
438
439 /* given/when context */
440 struct block_givwhen {
441         OP *leave_op;
442 };
443
444 #define PUSHGIVEN(cx)                                                   \
445         cx->blk_givwhen.leave_op = cLOGOP->op_other;
446
447 #define PUSHWHEN PUSHGIVEN
448
449 /* context common to subroutines, evals and loops */
450 struct block {
451     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
452     COP *       blku_oldcop;    /* old curcop pointer */
453     I32         blku_oldmarksp; /* mark stack index */
454     I32         blku_oldscopesp;        /* scope stack index */
455     PMOP *      blku_oldpm;     /* values of pattern match vars */
456     U8          blku_gimme;     /* is this block running in list context? */
457
458     union {
459         struct block_sub        blku_sub;
460         struct block_eval       blku_eval;
461         struct block_loop       blku_loop;
462         struct block_givwhen    blku_givwhen;
463     } blk_u;
464 };
465 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
466 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
467 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
468 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
469 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
470 #define blk_gimme       cx_u.cx_blk.blku_gimme
471 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
472 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
473 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
474 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
475
476 /* Enter a block. */
477 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
478         cx->cx_type             = t,                                    \
479         cx->blk_oldsp           = sp - PL_stack_base,                   \
480         cx->blk_oldcop          = PL_curcop,                            \
481         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
482         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
483         cx->blk_oldpm           = PL_curpm,                             \
484         cx->blk_gimme           = (U8)gimme;                            \
485         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
486                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
487
488 /* Exit a block (RETURN and LAST). */
489 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
490         newsp            = PL_stack_base + cx->blk_oldsp,               \
491         PL_curcop        = cx->blk_oldcop,                              \
492         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
493         PL_scopestack_ix = cx->blk_oldscopesp,                          \
494         pm               = cx->blk_oldpm,                               \
495         gimme            = cx->blk_gimme;                               \
496         DEBUG_SCOPE("POPBLOCK");                                        \
497         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
498                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
499
500 /* Continue a block elsewhere (NEXT and REDO). */
501 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
502         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
503         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
504         PL_scopestack_ix = cx->blk_oldscopesp,                          \
505         PL_curpm         = cx->blk_oldpm;                               \
506         DEBUG_SCOPE("TOPBLOCK");
507
508 /* substitution context */
509 struct subst {
510     I32         sbu_iters;
511     I32         sbu_maxiters;
512     I32         sbu_rflags;
513     I32         sbu_oldsave;
514     bool        sbu_once;
515     bool        sbu_rxtainted;
516     char *      sbu_orig;
517     SV *        sbu_dstr;
518     SV *        sbu_targ;
519     char *      sbu_s;
520     char *      sbu_m;
521     char *      sbu_strend;
522     void *      sbu_rxres;
523     REGEXP *    sbu_rx;
524 };
525 #define sb_iters        cx_u.cx_subst.sbu_iters
526 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
527 #define sb_rflags       cx_u.cx_subst.sbu_rflags
528 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
529 #define sb_once         cx_u.cx_subst.sbu_once
530 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
531 #define sb_orig         cx_u.cx_subst.sbu_orig
532 #define sb_dstr         cx_u.cx_subst.sbu_dstr
533 #define sb_targ         cx_u.cx_subst.sbu_targ
534 #define sb_s            cx_u.cx_subst.sbu_s
535 #define sb_m            cx_u.cx_subst.sbu_m
536 #define sb_strend       cx_u.cx_subst.sbu_strend
537 #define sb_rxres        cx_u.cx_subst.sbu_rxres
538 #define sb_rx           cx_u.cx_subst.sbu_rx
539
540 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
541         cx->sb_iters            = iters,                                \
542         cx->sb_maxiters         = maxiters,                             \
543         cx->sb_rflags           = r_flags,                              \
544         cx->sb_oldsave          = oldsave,                              \
545         cx->sb_once             = once,                                 \
546         cx->sb_rxtainted        = rxtainted,                            \
547         cx->sb_orig             = orig,                                 \
548         cx->sb_dstr             = dstr,                                 \
549         cx->sb_targ             = targ,                                 \
550         cx->sb_s                = s,                                    \
551         cx->sb_m                = m,                                    \
552         cx->sb_strend           = strend,                               \
553         cx->sb_rxres            = NULL,                                 \
554         cx->sb_rx               = rx,                                   \
555         cx->cx_type             = CXt_SUBST;                            \
556         rxres_save(&cx->sb_rxres, rx)
557
558 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
559         rxres_free(&cx->sb_rxres)
560
561 struct context {
562     U32         cx_type;        /* what kind of context this is */
563     union {
564         struct block    cx_blk;
565         struct subst    cx_subst;
566     } cx_u;
567 };
568
569 #define CXTYPEMASK      0xff
570 #define CXt_NULL        0
571 #define CXt_SUB         1
572 #define CXt_EVAL        2
573 #define CXt_LOOP        3
574 #define CXt_SUBST       4
575 #define CXt_BLOCK       5
576 #define CXt_FORMAT      6
577 #define CXt_GIVEN       7
578 #define CXt_WHEN        8
579
580 /* private flags for CXt_SUB and CXt_NULL */
581 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
582                                            tear down context on exit). */ 
583
584 /* private flags for CXt_EVAL */
585 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
586 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
587
588 /* private flags for CXt_LOOP */
589 #define CXp_FOREACH     0x00000200      /* a foreach loop */
590 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
591 #ifdef USE_ITHREADS
592 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
593                                            has pad offset; if not set,
594                                            iterdata holds GV* */
595 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
596                          == (CXt_LOOP|CXp_PADVAR))
597 #endif
598
599 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
600 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
601                          == CXp_MULTICALL)
602 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
603                          == (CXt_EVAL|CXp_REAL))
604 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
605                          == (CXt_EVAL|CXp_TRYBLOCK))
606 #define CxFOREACH(c)    (((c)->cx_type & (CXt_LOOP|CXp_FOREACH))        \
607                          == (CXt_LOOP|CXp_FOREACH))
608 #define CxFOREACHDEF(c) (((c)->cx_type & (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))\
609                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
610
611 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
612
613 /* 
614 =head1 "Gimme" Values
615 */
616
617 /*
618 =for apidoc AmU||G_SCALAR
619 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
620 L<perlcall>.
621
622 =for apidoc AmU||G_ARRAY
623 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
624 L<perlcall>.
625
626 =for apidoc AmU||G_VOID
627 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
628
629 =for apidoc AmU||G_DISCARD
630 Indicates that arguments returned from a callback should be discarded.  See
631 L<perlcall>.
632
633 =for apidoc AmU||G_EVAL
634
635 Used to force a Perl C<eval> wrapper around a callback.  See
636 L<perlcall>.
637
638 =for apidoc AmU||G_NOARGS
639
640 Indicates that no arguments are being sent to a callback.  See
641 L<perlcall>.
642
643 =cut
644 */
645
646 #define G_SCALAR        0
647 #define G_ARRAY         1
648 #define G_VOID          128     /* skip this bit when adding flags below */
649
650 /* extra flags for Perl_call_* routines */
651 #define G_DISCARD       2       /* Call FREETMPS. */
652 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
653 #define G_NOARGS        8       /* Don't construct a @_ array. */
654 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
655 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
656 #define G_METHOD       64       /* Calling method. */
657 #define G_FAKINGEVAL  256       /* Faking en eval context for call_sv or
658                                    fold_constants. */
659
660 /* flag bits for PL_in_eval */
661 #define EVAL_NULL       0       /* not in an eval */
662 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
663 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
664 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
665 #define EVAL_INREQUIRE  8       /* The code is being required. */
666
667 /* Support for switching (stack and block) contexts.
668  * This ensures magic doesn't invalidate local stack and cx pointers.
669  */
670
671 #define PERLSI_UNKNOWN          -1
672 #define PERLSI_UNDEF            0
673 #define PERLSI_MAIN             1
674 #define PERLSI_MAGIC            2
675 #define PERLSI_SORT             3
676 #define PERLSI_SIGNAL           4
677 #define PERLSI_OVERLOAD         5
678 #define PERLSI_DESTROY          6
679 #define PERLSI_WARNHOOK         7
680 #define PERLSI_DIEHOOK          8
681 #define PERLSI_REQUIRE          9
682
683 struct stackinfo {
684     AV *                si_stack;       /* stack for current runlevel */
685     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
686     I32                 si_cxix;        /* current context index */
687     I32                 si_cxmax;       /* maximum allocated index */
688     I32                 si_type;        /* type of runlevel */
689     struct stackinfo *  si_prev;
690     struct stackinfo *  si_next;
691     I32                 si_markoff;     /* offset where markstack begins for us.
692                                          * currently used only with DEBUGGING,
693                                          * but not #ifdef-ed for bincompat */
694 };
695
696 typedef struct stackinfo PERL_SI;
697
698 #define cxstack         (PL_curstackinfo->si_cxstack)
699 #define cxstack_ix      (PL_curstackinfo->si_cxix)
700 #define cxstack_max     (PL_curstackinfo->si_cxmax)
701
702 #ifdef DEBUGGING
703 #  define       SET_MARK_OFFSET \
704     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
705 #else
706 #  define       SET_MARK_OFFSET NOOP
707 #endif
708
709 #define PUSHSTACKi(type) \
710     STMT_START {                                                        \
711         PERL_SI *next = PL_curstackinfo->si_next;                       \
712         if (!next) {                                                    \
713             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
714             next->si_prev = PL_curstackinfo;                            \
715             PL_curstackinfo->si_next = next;                            \
716         }                                                               \
717         next->si_type = type;                                           \
718         next->si_cxix = -1;                                             \
719         AvFILLp(next->si_stack) = 0;                                    \
720         SWITCHSTACK(PL_curstack,next->si_stack);                        \
721         PL_curstackinfo = next;                                         \
722         SET_MARK_OFFSET;                                                \
723     } STMT_END
724
725 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
726
727 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
728  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
729 #define POPSTACK \
730     STMT_START {                                                        \
731         dSP;                                                            \
732         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
733         if (!prev) {                                                    \
734             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
735             my_exit(1);                                                 \
736         }                                                               \
737         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
738         /* don't free prev here, free them all at the END{} */          \
739         PL_curstackinfo = prev;                                         \
740     } STMT_END
741
742 #define POPSTACK_TO(s) \
743     STMT_START {                                                        \
744         while (PL_curstack != s) {                                      \
745             dounwind(-1);                                               \
746             POPSTACK;                                                   \
747         }                                                               \
748     } STMT_END
749
750 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
751 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
752
753 /*
754 =head1 Multicall Functions
755
756 =for apidoc Ams||dMULTICALL
757 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
758
759 =for apidoc Ams||PUSH_MULTICALL
760 Opening bracket for a lightweight callback.
761 See L<perlcall/Lightweight Callbacks>.
762
763 =for apidoc Ams||MULTICALL
764 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
765
766 =for apidoc Ams||POP_MULTICALL
767 Closing bracket for a lightweight callback.
768 See L<perlcall/Lightweight Callbacks>.
769
770 =cut
771 */
772
773 #define dMULTICALL \
774     SV **newsp;                 /* set by POPBLOCK */                   \
775     PERL_CONTEXT *cx;                                                   \
776     CV *multicall_cv;                                                   \
777     OP *multicall_cop;                                                  \
778     bool multicall_oldcatch;                                            \
779     U8 hasargs = 0              /* used by PUSHSUB */
780
781 #define PUSH_MULTICALL(the_cv) \
782     STMT_START {                                                        \
783         CV * const _nOnclAshIngNamE_ = the_cv;                          \
784         CV * const cv = _nOnclAshIngNamE_;                              \
785         AV * const padlist = CvPADLIST(cv);                             \
786         ENTER;                                                          \
787         multicall_oldcatch = CATCH_GET;                                 \
788         SAVETMPS; SAVEVPTR(PL_op);                                      \
789         CATCH_SET(TRUE);                                                \
790         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
791         PUSHSUB(cx);                                                    \
792         if (++CvDEPTH(cv) >= 2) {                                       \
793             PERL_STACK_OVERFLOW_CHECK();                                \
794             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
795         }                                                               \
796         SAVECOMPPAD();                                                  \
797         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
798         multicall_cv = cv;                                              \
799         multicall_cop = CvSTART(cv);                                    \
800     } STMT_END
801
802 #define MULTICALL \
803     STMT_START {                                                        \
804         PL_op = multicall_cop;                                          \
805         CALLRUNOPS(aTHX);                                               \
806     } STMT_END
807
808 #define POP_MULTICALL \
809     STMT_START {                                                        \
810         LEAVESUB(multicall_cv);                                         \
811         CvDEPTH(multicall_cv)--;                                        \
812         POPBLOCK(cx,PL_curpm);                                          \
813         CATCH_SET(multicall_oldcatch);                                  \
814         LEAVE;                                                          \
815     } STMT_END
816
817 /*
818  * Local variables:
819  * c-indentation-style: bsd
820  * c-basic-offset: 4
821  * indent-tabs-mode: t
822  * End:
823  *
824  * ex: set ts=8 sts=4 sw=4 noet:
825  */