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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     U8          hasargs;
286     U8          lval;           /* XXX merge lval and hasargs? */
287     /* Above here is the same for sub and format.  */
288     AV *        savearray;
289     AV *        argarray;
290     I32         olddepth;
291     PAD         *oldcomppad;
292 };
293
294
295 /* format context */
296 struct block_format {
297     OP *        retop;  /* op to execute on exit from sub */
298     /* Above here is the same for sub, format and eval.  */
299     CV *        cv;
300     U8          hasargs;
301     U8          lval;           /* XXX merge lval and hasargs? */
302     /* Above here is the same for sub and format.  */
303     GV *        gv;
304     GV *        dfoutgv;
305 };
306
307 /* base for the next two macros. Don't use directly.
308  * Note that the refcnt of the cv is incremented twice;  The CX one is
309  * decremented by LEAVESUB, the other by LEAVE. */
310
311 #define PUSHSUB_BASE(cx)                                                \
312         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
313                 CopFILE((COP*)CvSTART(cv)),                             \
314                 CopLINE((COP*)CvSTART(cv)));                            \
315                                                                         \
316         cx->blk_sub.cv = cv;                                            \
317         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
318         cx->blk_sub.hasargs = hasargs;                                  \
319         cx->blk_sub.retop = NULL;                                       \
320         if (!CvDEPTH(cv)) {                                             \
321             SvREFCNT_inc_simple_void_NN(cv);                            \
322             SvREFCNT_inc_simple_void_NN(cv);                            \
323             SAVEFREESV(cv);                                             \
324         }
325
326
327 #define PUSHSUB(cx)                                                     \
328         PUSHSUB_BASE(cx)                                                \
329         cx->blk_sub.lval = PL_op->op_private &                          \
330                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
331
332 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
333 #define PUSHSUB_DB(cx)                                                  \
334         PUSHSUB_BASE(cx)                                                \
335         cx->blk_sub.lval = 0;
336
337
338 #define PUSHFORMAT(cx, retop)                                           \
339         cx->blk_format.cv = cv;                                         \
340         cx->blk_format.gv = gv;                                         \
341         cx->blk_format.retop = (retop);                                 \
342         cx->blk_format.hasargs = 0;                                     \
343         cx->blk_format.dfoutgv = PL_defoutgv;                           \
344         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
345
346 #define POP_SAVEARRAY()                                         \
347     STMT_START {                                                        \
348         SvREFCNT_dec(GvAV(PL_defgv));                                   \
349         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
350     } STMT_END
351
352 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
353  * leave any (a fast av_clear(ary), basically) */
354 #define CLEAR_ARGARRAY(ary) \
355     STMT_START {                                                        \
356         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
357         AvARRAY(ary) = AvALLOC(ary);                                    \
358         AvFILLp(ary) = -1;                                              \
359     } STMT_END
360
361 #define POPSUB(cx,sv)                                                   \
362     STMT_START {                                                        \
363         RETURN_PROBE(GvENAME(CvGV((CV*)cx->blk_sub.cv)),                \
364                 CopFILE((COP*)CvSTART((CV*)cx->blk_sub.cv)),            \
365                 CopLINE((COP*)CvSTART((CV*)cx->blk_sub.cv)));           \
366                                                                         \
367         if (CxHASARGS(cx)) {                                            \
368             POP_SAVEARRAY();                                            \
369             /* abandon @_ if it got reified */                          \
370             if (AvREAL(cx->blk_sub.argarray)) {                         \
371                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
372                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
373                 cx->blk_sub.argarray = newAV();                         \
374                 av_extend(cx->blk_sub.argarray, fill);                  \
375                 AvREIFY_only(cx->blk_sub.argarray);                     \
376                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
377             }                                                           \
378             else {                                                      \
379                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
380             }                                                           \
381         }                                                               \
382         sv = (SV*)cx->blk_sub.cv;                                       \
383         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
384             sv = NULL;                                          \
385     } STMT_END
386
387 #define LEAVESUB(sv)                                                    \
388     STMT_START {                                                        \
389         if (sv)                                                         \
390             SvREFCNT_dec(sv);                                           \
391     } STMT_END
392
393 #define POPFORMAT(cx)                                                   \
394         setdefout(cx->blk_format.dfoutgv);                              \
395         SvREFCNT_dec(cx->blk_format.dfoutgv);
396
397 /* eval context */
398 struct block_eval {
399     OP *        retop;  /* op to execute on exit from eval */
400     /* Above here is the same for sub, format and eval.  */
401     U8          old_in_eval;
402     U16         old_op_type;
403     SV *        old_namesv;
404     OP *        old_eval_root;
405     SV *        cur_text;
406     CV *        cv;
407     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
408 };
409
410 #define PUSHEVAL(cx,n,fgv)                                              \
411     STMT_START {                                                        \
412         cx->blk_eval.old_in_eval = PL_in_eval;                          \
413         cx->blk_eval.old_op_type = PL_op->op_type;                      \
414         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
415         cx->blk_eval.old_eval_root = PL_eval_root;                      \
416         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
417         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
418         cx->blk_eval.retop = NULL;                                      \
419         cx->blk_eval.cur_top_env = PL_top_env;                          \
420     } STMT_END
421
422 #define POPEVAL(cx)                                                     \
423     STMT_START {                                                        \
424         PL_in_eval = cx->blk_eval.old_in_eval;                          \
425         optype = cx->blk_eval.old_op_type;                              \
426         PL_eval_root = cx->blk_eval.old_eval_root;                      \
427         if (cx->blk_eval.old_namesv)                                    \
428             sv_2mortal(cx->blk_eval.old_namesv);                        \
429     } STMT_END
430
431 /* loop context */
432 struct block_loop {
433     I32         resetsp;
434     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
435     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
436         why next_op is conditionally defined below.)  */
437 #ifdef USE_ITHREADS
438     void *      iterdata;
439     PAD         *oldcomppad;
440 #else
441     OP *        next_op;
442     SV **       itervar;
443 #endif
444     SV *        itersave;
445     /* (from inspection of source code) for a .. range of strings this is the
446        current string.  */
447     SV *        iterlval;
448     /* (from inspection of source code) for a foreach loop this is the array
449        being iterated over. For a .. range of numbers it's the current value.
450        A check is often made on the SvTYPE of iterary to determine whether
451        we are iterating over an array or a range. (numbers or strings)  */
452     AV *        iterary;
453     IV          iterix;
454     /* (from inspection of source code) for a .. range of numbers this is the
455        maximum value.  */
456     IV          itermax;
457 };
458 /* It might be possible to squeeze this structure further. As best I can tell
459    itermax and iterlval are never used at the same time, so it might be possible
460    to make them into a union. However, I'm not confident that there are enough
461    flag bits/NULLable pointers in this structure alone to encode which is
462    active. There is, however, U8 of space free in struct block, which could be
463    used. Right now it may not be worth squeezing this structure further, as it's
464    the largest part of struct block, and currently struct block is 64 bytes on
465    an ILP32 system, which will give good cache alignment.
466 */
467
468 #ifdef USE_ITHREADS
469 #  define CxITERVAR(c)                                                  \
470         ((c)->blk_loop.iterdata                                         \
471          ? (CxPADLOOP(cx)                                               \
472             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
473                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
474             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
475          : (SV**)NULL)
476 #  define CX_ITERDATA_SET(cx,idata)                                     \
477         CX_CURPAD_SAVE(cx->blk_loop);                                   \
478         if ((cx->blk_loop.iterdata = (idata)))                          \
479             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
480         else                                                            \
481             cx->blk_loop.itersave = NULL;
482 #else
483 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
484 #  define CX_ITERDATA_SET(cx,ivar)                                      \
485         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
486             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
487         else                                                            \
488             cx->blk_loop.itersave = NULL;
489 #endif
490 #define CxLABEL(c)      (0 + (c)->blk_oldcop->cop_label)
491 #define CxHASARGS(c)    (0 + (c)->blk_sub.hasargs)
492 #define CxLVAL(c)       (0 + (c)->blk_sub.lval)
493
494 #ifdef USE_ITHREADS
495 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
496 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
497 #else
498 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
499 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
500 #endif
501
502 #define PUSHLOOP(cx, dat, s)                                            \
503         cx->blk_loop.resetsp = s - PL_stack_base;                       \
504         cx->blk_loop.my_op = cLOOP;                                     \
505         PUSHLOOP_OP_NEXT;                                               \
506         cx->blk_loop.iterlval = NULL;                                   \
507         cx->blk_loop.iterary = NULL;                                    \
508         cx->blk_loop.iterix = -1;                                       \
509         CX_ITERDATA_SET(cx,dat);
510
511 #define POPLOOP(cx)                                                     \
512         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
513         if (CxITERVAR(cx)) {                                            \
514             if (SvPADMY(cx->blk_loop.itersave)) {                       \
515                 SV ** const s_v_p = CxITERVAR(cx);                      \
516                 sv_2mortal(*s_v_p);                                     \
517                 *s_v_p = cx->blk_loop.itersave;                         \
518             }                                                           \
519             else {                                                      \
520                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
521             }                                                           \
522         }                                                               \
523         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
524             SvREFCNT_dec(cx->blk_loop.iterary);
525
526 /* given/when context */
527 struct block_givwhen {
528         OP *leave_op;
529 };
530
531 #define PUSHGIVEN(cx)                                                   \
532         cx->blk_givwhen.leave_op = cLOGOP->op_other;
533
534 #define PUSHWHEN PUSHGIVEN
535
536 /* context common to subroutines, evals and loops */
537 struct block {
538     U16         blku_type;      /* what kind of context this is */
539     U8          blku_gimme;     /* is this block running in list context? */
540     U8          blku_spare;     /* Padding to match with struct subst */
541     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
542     COP *       blku_oldcop;    /* old curcop pointer */
543     I32         blku_oldmarksp; /* mark stack index */
544     I32         blku_oldscopesp;        /* scope stack index */
545     PMOP *      blku_oldpm;     /* values of pattern match vars */
546
547     union {
548         struct block_sub        blku_sub;
549         struct block_format     blku_format;
550         struct block_eval       blku_eval;
551         struct block_loop       blku_loop;
552         struct block_givwhen    blku_givwhen;
553     } blk_u;
554 };
555 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
556 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
557 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
558 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
559 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
560 #define blk_gimme       cx_u.cx_blk.blku_gimme
561 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
562 #define blk_format      cx_u.cx_blk.blk_u.blku_format
563 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
564 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
565 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
566
567 /* Enter a block. */
568 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
569         cx->cx_type             = t,                                    \
570         cx->blk_oldsp           = sp - PL_stack_base,                   \
571         cx->blk_oldcop          = PL_curcop,                            \
572         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
573         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
574         cx->blk_oldpm           = PL_curpm,                             \
575         cx->blk_gimme           = (U8)gimme;                            \
576         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
577                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
578
579 /* Exit a block (RETURN and LAST). */
580 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
581         newsp            = PL_stack_base + cx->blk_oldsp,               \
582         PL_curcop        = cx->blk_oldcop,                              \
583         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
584         PL_scopestack_ix = cx->blk_oldscopesp,                          \
585         pm               = cx->blk_oldpm,                               \
586         gimme            = cx->blk_gimme;                               \
587         DEBUG_SCOPE("POPBLOCK");                                        \
588         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
589                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
590
591 /* Continue a block elsewhere (NEXT and REDO). */
592 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
593         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
594         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
595         PL_scopestack_ix = cx->blk_oldscopesp,                          \
596         PL_curpm         = cx->blk_oldpm;                               \
597         DEBUG_SCOPE("TOPBLOCK");
598
599 /* substitution context */
600 struct subst {
601     U16         sbu_type;       /* what kind of context this is */
602     U8          sbu_once;       /* Actually both booleans, but U8 to matches */
603     U8          sbu_rxtainted;  /* struct block */
604     I32         sbu_iters;
605     I32         sbu_maxiters;
606     I32         sbu_rflags;
607     I32         sbu_oldsave;
608     char *      sbu_orig;
609     SV *        sbu_dstr;
610     SV *        sbu_targ;
611     char *      sbu_s;
612     char *      sbu_m;
613     char *      sbu_strend;
614     void *      sbu_rxres;
615     REGEXP *    sbu_rx;
616 };
617 #define sb_iters        cx_u.cx_subst.sbu_iters
618 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
619 #define sb_rflags       cx_u.cx_subst.sbu_rflags
620 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
621 #define sb_once         cx_u.cx_subst.sbu_once
622 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
623 #define sb_orig         cx_u.cx_subst.sbu_orig
624 #define sb_dstr         cx_u.cx_subst.sbu_dstr
625 #define sb_targ         cx_u.cx_subst.sbu_targ
626 #define sb_s            cx_u.cx_subst.sbu_s
627 #define sb_m            cx_u.cx_subst.sbu_m
628 #define sb_strend       cx_u.cx_subst.sbu_strend
629 #define sb_rxres        cx_u.cx_subst.sbu_rxres
630 #define sb_rx           cx_u.cx_subst.sbu_rx
631
632 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
633         cx->sb_iters            = iters,                                \
634         cx->sb_maxiters         = maxiters,                             \
635         cx->sb_rflags           = r_flags,                              \
636         cx->sb_oldsave          = oldsave,                              \
637         cx->sb_once             = once,                                 \
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;                            \
648         rxres_save(&cx->sb_rxres, rx);                                  \
649         (void)ReREFCNT_inc(rx)
650
651 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
652         rxres_free(&cx->sb_rxres);                                      \
653         ReREFCNT_dec(cx->sb_rx)
654
655 struct context {
656     union {
657         struct block    cx_blk;
658         struct subst    cx_subst;
659     } cx_u;
660 };
661 #define cx_type cx_u.cx_subst.sbu_type
662
663 #define CXTYPEMASK      0xff
664 #define CXt_NULL        0
665 #define CXt_SUB         1
666 #define CXt_EVAL        2
667 #define CXt_LOOP        3
668 #define CXt_SUBST       4
669 #define CXt_BLOCK       5
670 #define CXt_FORMAT      6
671 #define CXt_GIVEN       7
672 #define CXt_WHEN        8
673
674 /* private flags for CXt_SUB and CXt_NULL */
675 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
676                                            tear down context on exit). */ 
677
678 /* private flags for CXt_EVAL */
679 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
680 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
681
682 /* private flags for CXt_LOOP */
683 #define CXp_FOREACH     0x00000200      /* a foreach loop */
684 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
685 #ifdef USE_ITHREADS
686 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
687                                            has pad offset; if not set,
688                                            iterdata holds GV* */
689 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
690                          == (CXt_LOOP|CXp_PADVAR))
691 #endif
692
693 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
694 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
695                          == CXp_MULTICALL)
696 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
697                          == (CXt_EVAL|CXp_REAL))
698 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
699                          == (CXt_EVAL|CXp_TRYBLOCK))
700 #define CxFOREACH(c)    (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH))      \
701                          == (CXt_LOOP|CXp_FOREACH))
702 #define CxFOREACHDEF(c) (((c)->cx_type & (CXTYPEMASK|CXp_FOREACH|CXp_FOR_DEF))\
703                          == (CXt_LOOP|CXp_FOREACH|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        0
741 #define G_ARRAY         1
742 #define G_VOID          128     /* skip this bit when adding flags below */
743
744 /* extra flags for Perl_call_* routines */
745 #define G_DISCARD       2       /* Call FREETMPS.
746                                    Don't change this without consulting the
747                                    hash actions codes defined in hv.h */
748 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
749 #define G_NOARGS        8       /* Don't construct a @_ array. */
750 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
751 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
752 #define G_METHOD       64       /* Calling method. */
753 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
754                                    fold_constants. */
755
756 /* flag bits for PL_in_eval */
757 #define EVAL_NULL       0       /* not in an eval */
758 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
759 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
760 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
761 #define EVAL_INREQUIRE  8       /* The code is being required. */
762
763 /* Support for switching (stack and block) contexts.
764  * This ensures magic doesn't invalidate local stack and cx pointers.
765  */
766
767 #define PERLSI_UNKNOWN          -1
768 #define PERLSI_UNDEF            0
769 #define PERLSI_MAIN             1
770 #define PERLSI_MAGIC            2
771 #define PERLSI_SORT             3
772 #define PERLSI_SIGNAL           4
773 #define PERLSI_OVERLOAD         5
774 #define PERLSI_DESTROY          6
775 #define PERLSI_WARNHOOK         7
776 #define PERLSI_DIEHOOK          8
777 #define PERLSI_REQUIRE          9
778
779 struct stackinfo {
780     AV *                si_stack;       /* stack for current runlevel */
781     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
782     struct stackinfo *  si_prev;
783     struct stackinfo *  si_next;
784     I32                 si_cxix;        /* current context index */
785     I32                 si_cxmax;       /* maximum allocated index */
786     I32                 si_type;        /* type of runlevel */
787     I32                 si_markoff;     /* offset where markstack begins for us.
788                                          * currently used only with DEBUGGING,
789                                          * but not #ifdef-ed for bincompat */
790 };
791
792 typedef struct stackinfo PERL_SI;
793
794 #define cxstack         (PL_curstackinfo->si_cxstack)
795 #define cxstack_ix      (PL_curstackinfo->si_cxix)
796 #define cxstack_max     (PL_curstackinfo->si_cxmax)
797
798 #ifdef DEBUGGING
799 #  define       SET_MARK_OFFSET \
800     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
801 #else
802 #  define       SET_MARK_OFFSET NOOP
803 #endif
804
805 #define PUSHSTACKi(type) \
806     STMT_START {                                                        \
807         PERL_SI *next = PL_curstackinfo->si_next;                       \
808         if (!next) {                                                    \
809             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
810             next->si_prev = PL_curstackinfo;                            \
811             PL_curstackinfo->si_next = next;                            \
812         }                                                               \
813         next->si_type = type;                                           \
814         next->si_cxix = -1;                                             \
815         AvFILLp(next->si_stack) = 0;                                    \
816         SWITCHSTACK(PL_curstack,next->si_stack);                        \
817         PL_curstackinfo = next;                                         \
818         SET_MARK_OFFSET;                                                \
819     } STMT_END
820
821 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
822
823 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
824  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
825 #define POPSTACK \
826     STMT_START {                                                        \
827         dSP;                                                            \
828         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
829         if (!prev) {                                                    \
830             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
831             my_exit(1);                                                 \
832         }                                                               \
833         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
834         /* don't free prev here, free them all at the END{} */          \
835         PL_curstackinfo = prev;                                         \
836     } STMT_END
837
838 #define POPSTACK_TO(s) \
839     STMT_START {                                                        \
840         while (PL_curstack != s) {                                      \
841             dounwind(-1);                                               \
842             POPSTACK;                                                   \
843         }                                                               \
844     } STMT_END
845
846 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
847 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
848
849 /*
850 =head1 Multicall Functions
851
852 =for apidoc Ams||dMULTICALL
853 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
854
855 =for apidoc Ams||PUSH_MULTICALL
856 Opening bracket for a lightweight callback.
857 See L<perlcall/Lightweight Callbacks>.
858
859 =for apidoc Ams||MULTICALL
860 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
861
862 =for apidoc Ams||POP_MULTICALL
863 Closing bracket for a lightweight callback.
864 See L<perlcall/Lightweight Callbacks>.
865
866 =cut
867 */
868
869 #define dMULTICALL \
870     SV **newsp;                 /* set by POPBLOCK */                   \
871     PERL_CONTEXT *cx;                                                   \
872     CV *multicall_cv;                                                   \
873     OP *multicall_cop;                                                  \
874     bool multicall_oldcatch;                                            \
875     U8 hasargs = 0              /* used by PUSHSUB */
876
877 #define PUSH_MULTICALL(the_cv) \
878     STMT_START {                                                        \
879         CV * const _nOnclAshIngNamE_ = the_cv;                          \
880         CV * const cv = _nOnclAshIngNamE_;                              \
881         AV * const padlist = CvPADLIST(cv);                             \
882         ENTER;                                                          \
883         multicall_oldcatch = CATCH_GET;                                 \
884         SAVETMPS; SAVEVPTR(PL_op);                                      \
885         CATCH_SET(TRUE);                                                \
886         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
887         PUSHSUB(cx);                                                    \
888         if (++CvDEPTH(cv) >= 2) {                                       \
889             PERL_STACK_OVERFLOW_CHECK();                                \
890             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
891         }                                                               \
892         SAVECOMPPAD();                                                  \
893         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
894         multicall_cv = cv;                                              \
895         multicall_cop = CvSTART(cv);                                    \
896     } STMT_END
897
898 #define MULTICALL \
899     STMT_START {                                                        \
900         PL_op = multicall_cop;                                          \
901         CALLRUNOPS(aTHX);                                               \
902     } STMT_END
903
904 #define POP_MULTICALL \
905     STMT_START {                                                        \
906         LEAVESUB(multicall_cv);                                         \
907         CvDEPTH(multicall_cv)--;                                        \
908         POPBLOCK(cx,PL_curpm);                                          \
909         CATCH_SET(multicall_oldcatch);                                  \
910         LEAVE;                                                          \
911     } STMT_END
912
913 /*
914  * Local variables:
915  * c-indentation-style: bsd
916  * c-basic-offset: 4
917  * indent-tabs-mode: t
918  * End:
919  *
920  * ex: set ts=8 sts=4 sw=4 noet:
921  */