[perl #9328] Update INSTALL example for BerkeleyDB install
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4  *    2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  * Control ops (cops) are one of the three ops OP_NEXTSTATE, OP_DBSTATE,
10  * and OP_SETSTATE that (loosely speaking) are separate statements.
11  * They hold information important for lexical state and error reporting.
12  * At run time, PL_curcop is set to point to the most recently executed cop,
13  * and thus can be used to determine our current state.
14  */
15
16 /* A jmpenv packages the state required to perform a proper non-local jump.
17  * Note that there is a start_env initialized when perl starts, and top_env
18  * points to this initially, so top_env should always be non-null.
19  *
20  * Existence of a non-null top_env->je_prev implies it is valid to call
21  * longjmp() at that runlevel (we make sure start_env.je_prev is always
22  * null to ensure this).
23  *
24  * je_mustcatch, when set at any runlevel to TRUE, means eval ops must
25  * establish a local jmpenv to handle exception traps.  Care must be taken
26  * to restore the previous value of je_mustcatch before exiting the
27  * stack frame iff JMPENV_PUSH was not called in that stack frame.
28  * GSAR 97-03-27
29  */
30
31 struct jmpenv {
32     struct jmpenv *     je_prev;
33     Sigjmp_buf          je_buf;         /* only for use if !je_throw */
34     int                 je_ret;         /* last exception thrown */
35     bool                je_mustcatch;   /* need to call longjmp()? */
36 };
37
38 typedef struct jmpenv JMPENV;
39
40 #ifdef OP_IN_REGISTER
41 #define OP_REG_TO_MEM   PL_opsave = op
42 #define OP_MEM_TO_REG   op = PL_opsave
43 #else
44 #define OP_REG_TO_MEM   NOOP
45 #define OP_MEM_TO_REG   NOOP
46 #endif
47
48 /*
49  * How to build the first jmpenv.
50  *
51  * top_env needs to be non-zero. It points to an area
52  * in which longjmp() stuff is stored, as C callstack
53  * info there at least is thread specific this has to
54  * be per-thread. Otherwise a 'die' in a thread gives
55  * that thread the C stack of last thread to do an eval {}!
56  */
57
58 #define JMPENV_BOOTSTRAP \
59     STMT_START {                                \
60         Zero(&PL_start_env, 1, JMPENV);         \
61         PL_start_env.je_ret = -1;               \
62         PL_start_env.je_mustcatch = TRUE;       \
63         PL_top_env = &PL_start_env;             \
64     } STMT_END
65
66 /*
67  *   PERL_FLEXIBLE_EXCEPTIONS
68  * 
69  * All the flexible exceptions code has been removed.
70  * See the following threads for details:
71  *
72  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2004-07/msg00378.html
73  * 
74  * Joshua's original patches (which weren't applied) and discussion:
75  * 
76  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01396.html
77  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01489.html
78  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01491.html
79  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg01608.html
80  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02144.html
81  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1998-02/msg02998.html
82  * 
83  * Chip's reworked patch and discussion:
84  * 
85  *   http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-03/msg00520.html
86  * 
87  * The flaw in these patches (which went unnoticed at the time) was
88  * that they moved some code that could potentially die() out of the
89  * region protected by the setjmp()s.  This caused exceptions within
90  * END blocks and such to not be handled by the correct setjmp().
91  * 
92  * The original patches that introduces flexible exceptions were:
93  *
94  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=3386
95  *   http://public.activestate.com/cgi-bin/perlbrowse?patch=5162
96  */
97
98 #define dJMPENV         JMPENV cur_env
99
100 #define JMPENV_PUSH(v) \
101     STMT_START {                                                        \
102         DEBUG_l(Perl_deb(aTHX_ "Setting up jumplevel %p, was %p\n",     \
103                          (void*)&cur_env, (void*)PL_top_env));                  \
104         cur_env.je_prev = PL_top_env;                                   \
105         OP_REG_TO_MEM;                                                  \
106         cur_env.je_ret = PerlProc_setjmp(cur_env.je_buf, SCOPE_SAVES_SIGNAL_MASK);              \
107         OP_MEM_TO_REG;                                                  \
108         PL_top_env = &cur_env;                                          \
109         cur_env.je_mustcatch = FALSE;                                   \
110         (v) = cur_env.je_ret;                                           \
111     } STMT_END
112
113 #define JMPENV_POP \
114     STMT_START {                                                        \
115         DEBUG_l(Perl_deb(aTHX_ "popping jumplevel was %p, now %p\n",    \
116                          (void*)PL_top_env, (void*)cur_env.je_prev));                   \
117         PL_top_env = cur_env.je_prev;                                   \
118     } STMT_END
119
120 #define JMPENV_JUMP(v) \
121     STMT_START {                                                \
122         OP_REG_TO_MEM;                                          \
123         if (PL_top_env->je_prev)                                \
124             PerlProc_longjmp(PL_top_env->je_buf, (v));          \
125         if ((v) == 2)                                           \
126             PerlProc_exit(STATUS_EXIT);                         \
127         PerlIO_printf(PerlIO_stderr(), "panic: top_env\n");     \
128         PerlProc_exit(1);                                       \
129     } STMT_END
130
131 #define CATCH_GET               (PL_top_env->je_mustcatch)
132 #define CATCH_SET(v)            (PL_top_env->je_mustcatch = (v))
133
134
135 #include "mydtrace.h"
136
137 struct cop {
138     BASEOP
139     /* On LP64 putting this here takes advantage of the fact that BASEOP isn't
140        an exact multiple of 8 bytes to save structure padding.  */
141     line_t      cop_line;       /* line # of this command */
142     /* label for this construct is now stored in cop_hints_hash */
143 #ifdef USE_ITHREADS
144     char *      cop_stashpv;    /* package line was compiled in */
145     char *      cop_file;       /* file name the following line # is from */
146 #else
147     HV *        cop_stash;      /* package line was compiled in */
148     GV *        cop_filegv;     /* file the following line # is from */
149 #endif
150     U32         cop_hints;      /* hints bits from pragmata */
151     U32         cop_seq;        /* parse sequence number */
152     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
153     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
154     /* compile time state of %^H.  See the comment in op.c for how this is
155        used to recreate a hash to return from caller.  */
156     struct refcounted_he * cop_hints_hash;
157 };
158
159 #ifdef USE_ITHREADS
160 #  define CopFILE(c)            ((c)->cop_file)
161 #  define CopFILEGV(c)          (CopFILE(c) \
162                                  ? gv_fetchfile(CopFILE(c)) : NULL)
163                                  
164 #  ifdef NETWARE
165 #    define CopFILE_set(c,pv)   ((c)->cop_file = savepv(pv))
166 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savepv((pv),(l)))
167 #  else
168 #    define CopFILE_set(c,pv)   ((c)->cop_file = savesharedpv(pv))
169 #    define CopFILE_setn(c,pv,l)  ((c)->cop_file = savesharedpvn((pv),(l)))
170 #  endif
171
172 #  define CopFILESV(c)          (CopFILE(c) \
173                                  ? GvSV(gv_fetchfile(CopFILE(c))) : NULL)
174 #  define CopFILEAV(c)          (CopFILE(c) \
175                                  ? GvAV(gv_fetchfile(CopFILE(c))) : NULL)
176 #  ifdef DEBUGGING
177 #    define CopFILEAVx(c)       (assert(CopFILE(c)), \
178                                    GvAV(gv_fetchfile(CopFILE(c))))
179 #  else
180 #    define CopFILEAVx(c)       (GvAV(gv_fetchfile(CopFILE(c))))
181 #  endif
182 #  define CopSTASHPV(c)         ((c)->cop_stashpv)
183
184 #  ifdef NETWARE
185 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = ((pv) ? savepv(pv) : NULL))
186 #  else
187 #    define CopSTASHPV_set(c,pv)        ((c)->cop_stashpv = savesharedpv(pv))
188 #  endif
189
190 #  define CopSTASH(c)           (CopSTASHPV(c) \
191                                  ? gv_stashpv(CopSTASHPV(c),GV_ADD) : NULL)
192 #  define CopSTASH_set(c,hv)    CopSTASHPV_set(c, (hv) ? HvNAME_get(hv) : NULL)
193 #  define CopSTASH_eq(c,hv)     ((hv) && stashpv_hvname_match(c,hv))
194 #  ifdef NETWARE
195 #    define CopSTASH_free(c) SAVECOPSTASH_FREE(c)
196 #    define CopFILE_free(c) SAVECOPFILE_FREE(c)
197 #  else
198 #    define CopSTASH_free(c)    PerlMemShared_free(CopSTASHPV(c))
199 #    define CopFILE_free(c)     (PerlMemShared_free(CopFILE(c)),(CopFILE(c) = NULL))
200 #  endif
201 #else
202 #  define CopFILEGV(c)          ((c)->cop_filegv)
203 #  define CopFILEGV_set(c,gv)   ((c)->cop_filegv = (GV*)SvREFCNT_inc(gv))
204 #  define CopFILE_set(c,pv)     CopFILEGV_set((c), gv_fetchfile(pv))
205 #  define CopFILE_setn(c,pv,l)  CopFILEGV_set((c), gv_fetchfile_flags((pv),(l),0))
206 #  define CopFILESV(c)          (CopFILEGV(c) ? GvSV(CopFILEGV(c)) : NULL)
207 #  define CopFILEAV(c)          (CopFILEGV(c) ? GvAV(CopFILEGV(c)) : NULL)
208 #  ifdef DEBUGGING
209 #    define CopFILEAVx(c)       (assert(CopFILEGV(c)), GvAV(CopFILEGV(c)))
210 #  else
211 #    define CopFILEAVx(c)       (GvAV(CopFILEGV(c)))
212 # endif
213 #  define CopFILE(c)            (CopFILEGV(c) && GvSV(CopFILEGV(c)) \
214                                     ? SvPVX(GvSV(CopFILEGV(c))) : NULL)
215 #  define CopSTASH(c)           ((c)->cop_stash)
216 #  define CopSTASH_set(c,hv)    ((c)->cop_stash = (hv))
217 #  define CopSTASHPV(c)         (CopSTASH(c) ? HvNAME_get(CopSTASH(c)) : NULL)
218    /* cop_stash is not refcounted */
219 #  define CopSTASHPV_set(c,pv)  CopSTASH_set((c), gv_stashpv(pv,GV_ADD))
220 #  define CopSTASH_eq(c,hv)     (CopSTASH(c) == (hv))
221 #  define CopSTASH_free(c)      
222 #  define CopFILE_free(c)       (SvREFCNT_dec(CopFILEGV(c)),(CopFILEGV(c) = NULL))
223
224 #endif /* USE_ITHREADS */
225 #define CopLABEL(c)  Perl_fetch_cop_label(aTHX_ (c)->cop_hints_hash, NULL, NULL)
226 #define CopLABEL_alloc(pv)      ((pv)?savepv(pv):NULL)
227
228 #define CopSTASH_ne(c,hv)       (!CopSTASH_eq(c,hv))
229 #define CopLINE(c)              ((c)->cop_line)
230 #define CopLINE_inc(c)          (++CopLINE(c))
231 #define CopLINE_dec(c)          (--CopLINE(c))
232 #define CopLINE_set(c,l)        (CopLINE(c) = (l))
233
234 /* OutCopFILE() is CopFILE for output (caller, die, warn, etc.) */
235 #define OutCopFILE(c) CopFILE(c)
236
237 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
238    HINT_ARYBASE is set to indicate this.
239    Setting it is ineficient due to the need to create 2 mortal SVs, but as
240    using $[ is highly discouraged, no sane Perl code will be using it.  */
241 #define CopARYBASE_get(c)       \
242         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
243          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
244                                          "$[", 2, 0, 0))                \
245          : 0)
246 #define CopARYBASE_set(c, b) STMT_START { \
247         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
248             (c)->cop_hints |= HINT_ARYBASE;                             \
249             if ((c) == &PL_compiling)                                   \
250                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
251             (c)->cop_hints_hash                                         \
252                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
253                                         newSVpvs_flags("$[", SVs_TEMP), \
254                                         sv_2mortal(newSViv(b)));        \
255         }                                                               \
256     } STMT_END
257
258 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
259 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
260 #define CopHINTS_set(c, h)      STMT_START {                            \
261                                     (c)->cop_hints = (h);               \
262                                 } STMT_END
263
264 /*
265  * Here we have some enormously heavy (or at least ponderous) wizardry.
266  */
267
268 /* subroutine context */
269 struct block_sub {
270     OP *        retop;  /* op to execute on exit from sub */
271     /* Above here is the same for sub, format and eval.  */
272     CV *        cv;
273     /* Above here is the same for sub and format.  */
274     AV *        savearray;
275     AV *        argarray;
276     I32         olddepth;
277     PAD         *oldcomppad;
278 };
279
280
281 /* format context */
282 struct block_format {
283     OP *        retop;  /* op to execute on exit from sub */
284     /* Above here is the same for sub, format and eval.  */
285     CV *        cv;
286     /* Above here is the same for sub and format.  */
287     GV *        gv;
288     GV *        dfoutgv;
289 };
290
291 /* base for the next two macros. Don't use directly.
292  * Note that the refcnt of the cv is incremented twice;  The CX one is
293  * decremented by LEAVESUB, the other by LEAVE. */
294
295 #define PUSHSUB_BASE(cx)                                                \
296         ENTRY_PROBE(GvENAME(CvGV(cv)),                                  \
297                 CopFILE((const COP *)CvSTART(cv)),                      \
298                 CopLINE((const COP *)CvSTART(cv)));                     \
299                                                                         \
300         cx->blk_sub.cv = cv;                                            \
301         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
302         cx->cx_type |= (hasargs) ? CXp_HASARGS : 0;                     \
303         cx->blk_sub.retop = NULL;                                       \
304         if (!CvDEPTH(cv)) {                                             \
305             SvREFCNT_inc_simple_void_NN(cv);                            \
306             SvREFCNT_inc_simple_void_NN(cv);                            \
307             SAVEFREESV(cv);                                             \
308         }
309
310
311 #define PUSHSUB(cx)                                                     \
312         PUSHSUB_BASE(cx)                                                \
313         cx->blk_u16 = PL_op->op_private &                               \
314                               (OPpLVAL_INTRO|OPpENTERSUB_INARGS);
315
316 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
317 #define PUSHSUB_DB(cx)                                                  \
318         PUSHSUB_BASE(cx)                                                \
319         cx->blk_u16 = 0;
320
321
322 #define PUSHFORMAT(cx, retop)                                           \
323         cx->blk_format.cv = cv;                                         \
324         cx->blk_format.gv = gv;                                         \
325         cx->blk_format.retop = (retop);                                 \
326         cx->blk_format.dfoutgv = PL_defoutgv;                           \
327         SvREFCNT_inc_void(cx->blk_format.dfoutgv)
328
329 #define POP_SAVEARRAY()                                         \
330     STMT_START {                                                        \
331         SvREFCNT_dec(GvAV(PL_defgv));                                   \
332         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
333     } STMT_END
334
335 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
336  * leave any (a fast av_clear(ary), basically) */
337 #define CLEAR_ARGARRAY(ary) \
338     STMT_START {                                                        \
339         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
340         AvARRAY(ary) = AvALLOC(ary);                                    \
341         AvFILLp(ary) = -1;                                              \
342     } STMT_END
343
344 #define POPSUB(cx,sv)                                                   \
345     STMT_START {                                                        \
346         RETURN_PROBE(GvENAME(CvGV((const CV*)cx->blk_sub.cv)),          \
347                 CopFILE((COP*)CvSTART((const CV*)cx->blk_sub.cv)),      \
348                 CopLINE((COP*)CvSTART((const CV*)cx->blk_sub.cv)));     \
349                                                                         \
350         if (CxHASARGS(cx)) {                                            \
351             POP_SAVEARRAY();                                            \
352             /* abandon @_ if it got reified */                          \
353             if (AvREAL(cx->blk_sub.argarray)) {                         \
354                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
355                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
356                 cx->blk_sub.argarray = newAV();                         \
357                 av_extend(cx->blk_sub.argarray, fill);                  \
358                 AvREIFY_only(cx->blk_sub.argarray);                     \
359                 CX_CURPAD_SV(cx->blk_sub, 0) = MUTABLE_SV(cx->blk_sub.argarray); \
360             }                                                           \
361             else {                                                      \
362                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
363             }                                                           \
364         }                                                               \
365         sv = MUTABLE_SV(cx->blk_sub.cv);                                \
366         if (sv && (CvDEPTH((const CV*)sv) = cx->blk_sub.olddepth))      \
367             sv = NULL;                                          \
368     } STMT_END
369
370 #define LEAVESUB(sv)                                                    \
371     STMT_START {                                                        \
372         if (sv)                                                         \
373             SvREFCNT_dec(sv);                                           \
374     } STMT_END
375
376 #define POPFORMAT(cx)                                                   \
377         setdefout(cx->blk_format.dfoutgv);                              \
378         SvREFCNT_dec(cx->blk_format.dfoutgv);
379
380 /* eval context */
381 struct block_eval {
382     OP *        retop;  /* op to execute on exit from eval */
383     /* Above here is the same for sub, format and eval.  */
384     SV *        old_namesv;
385     OP *        old_eval_root;
386     SV *        cur_text;
387     CV *        cv;
388     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
389 };
390
391 /* If we ever need more than 512 op types, change the shift from 7.
392    blku_gimme is actually also only 2 bits, so could be merged with something.
393 */
394
395 #define CxOLD_IN_EVAL(cx)       (((cx)->blk_u16) & 0x7F)
396 #define CxOLD_OP_TYPE(cx)       (((cx)->blk_u16) >> 7)
397
398 #define PUSHEVAL(cx,n)                                                  \
399     STMT_START {                                                        \
400         assert(!(PL_in_eval & ~0x7F));                                  \
401         assert(!(PL_op->op_type & ~0x1FF));                             \
402         cx->blk_u16 = (PL_in_eval & 0x7F) | ((U16)PL_op->op_type << 7); \
403         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
404         cx->blk_eval.old_eval_root = PL_eval_root;                      \
405         cx->blk_eval.cur_text = PL_parser ? PL_parser->linestr : NULL;  \
406         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
407         cx->blk_eval.retop = NULL;                                      \
408         cx->blk_eval.cur_top_env = PL_top_env;                          \
409     } STMT_END
410
411 #define POPEVAL(cx)                                                     \
412     STMT_START {                                                        \
413         PL_in_eval = CxOLD_IN_EVAL(cx);                                 \
414         optype = CxOLD_OP_TYPE(cx);                                     \
415         PL_eval_root = cx->blk_eval.old_eval_root;                      \
416         if (cx->blk_eval.old_namesv)                                    \
417             sv_2mortal(cx->blk_eval.old_namesv);                        \
418     } STMT_END
419
420 /* loop context */
421 struct block_loop {
422     I32         resetsp;
423     LOOP *      my_op;  /* My op, that contains redo, next and last ops.  */
424     /* (except for non_ithreads we need to modify next_op in pp_ctl.c, hence
425         why next_op is conditionally defined below.)  */
426 #ifdef USE_ITHREADS
427     PAD         *oldcomppad; /* Also used for the GV, if targoffset is 0 */
428     /* This is also accesible via cx->blk_loop.my_op->op_targ */
429     PADOFFSET   targoffset;
430 #else
431     OP *        next_op;
432     SV **       itervar;
433 #endif
434     union {
435         struct { /* valid if type is LOOP_FOR or LOOP_PLAIN (but {NULL,0})*/
436             AV * ary; /* use the stack if this is NULL */
437             IV ix;
438         } ary;
439         struct { /* valid if type is LOOP_LAZYIV */
440             IV cur;
441             IV end;
442         } lazyiv;
443         struct { /* valid if type if LOOP_LAZYSV */
444             SV * cur;
445             SV * end; /* maxiumum value (or minimum in reverse) */
446         } lazysv;
447     } state_u;
448 };
449
450 #ifdef USE_ITHREADS
451 #  define CxITERVAR(c)                                                  \
452         ((c)->blk_loop.oldcomppad                                       \
453          ? (CxPADLOOP(c)                                                \
454             ? &CX_CURPAD_SV( (c)->blk_loop, (c)->blk_loop.targoffset )  \
455             : &GvSV((GV*)(c)->blk_loop.oldcomppad))                     \
456          : (SV**)NULL)
457 #  define CX_ITERDATA_SET(cx,idata,o)                                   \
458         if ((cx->blk_loop.targoffset = (o)))                            \
459             CX_CURPAD_SAVE(cx->blk_loop);                               \
460         else                                                            \
461             cx->blk_loop.oldcomppad = (idata);
462 #else
463 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
464 #  define CX_ITERDATA_SET(cx,ivar,o)                                    \
465         cx->blk_loop.itervar = (SV**)(ivar);
466 #endif
467 #define CxLABEL(c)      (0 + CopLABEL((c)->blk_oldcop))
468 #define CxHASARGS(c)    (((c)->cx_type & CXp_HASARGS) == CXp_HASARGS)
469 #define CxLVAL(c)       (0 + (c)->blk_u16)
470
471 #ifdef USE_ITHREADS
472 #  define PUSHLOOP_OP_NEXT              /* No need to do anything.  */
473 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.my_op->op_nextop + 0)
474 #else
475 #  define PUSHLOOP_OP_NEXT              cx->blk_loop.next_op = cLOOP->op_nextop
476 #  define CX_LOOP_NEXTOP_GET(cx)        ((cx)->blk_loop.next_op + 0)
477 #endif
478
479 #define PUSHLOOP_PLAIN(cx, s)                                           \
480         cx->blk_loop.resetsp = s - PL_stack_base;                       \
481         cx->blk_loop.my_op = cLOOP;                                     \
482         PUSHLOOP_OP_NEXT;                                               \
483         cx->blk_loop.state_u.ary.ary = NULL;                            \
484         cx->blk_loop.state_u.ary.ix = 0;                                \
485         CX_ITERDATA_SET(cx, NULL, 0);
486
487 #define PUSHLOOP_FOR(cx, dat, s, offset)                                \
488         cx->blk_loop.resetsp = s - PL_stack_base;                       \
489         cx->blk_loop.my_op = cLOOP;                                     \
490         PUSHLOOP_OP_NEXT;                                               \
491         cx->blk_loop.state_u.ary.ary = NULL;                            \
492         cx->blk_loop.state_u.ary.ix = 0;                                \
493         CX_ITERDATA_SET(cx, dat, offset);
494
495 #define POPLOOP(cx)                                                     \
496         if (CxTYPE(cx) == CXt_LOOP_LAZYSV) {                            \
497             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.cur);              \
498             SvREFCNT_dec(cx->blk_loop.state_u.lazysv.end);              \
499         }                                                               \
500         if (CxTYPE(cx) == CXt_LOOP_FOR)                                 \
501             SvREFCNT_dec(cx->blk_loop.state_u.ary.ary);
502
503 /* given/when context */
504 struct block_givwhen {
505         OP *leave_op;
506 };
507
508 #define PUSHGIVEN(cx)                                                   \
509         cx->blk_givwhen.leave_op = cLOGOP->op_other;
510
511 #define PUSHWHEN PUSHGIVEN
512
513 /* context common to subroutines, evals and loops */
514 struct block {
515     U8          blku_type;      /* what kind of context this is */
516     U8          blku_gimme;     /* is this block running in list context? */
517     U16         blku_u16;       /* used by block_sub and block_eval (so far) */
518     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
519     COP *       blku_oldcop;    /* old curcop pointer */
520     I32         blku_oldmarksp; /* mark stack index */
521     I32         blku_oldscopesp;        /* scope stack index */
522     PMOP *      blku_oldpm;     /* values of pattern match vars */
523
524     union {
525         struct block_sub        blku_sub;
526         struct block_format     blku_format;
527         struct block_eval       blku_eval;
528         struct block_loop       blku_loop;
529         struct block_givwhen    blku_givwhen;
530     } blk_u;
531 };
532 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
533 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
534 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
535 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
536 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
537 #define blk_gimme       cx_u.cx_blk.blku_gimme
538 #define blk_u16         cx_u.cx_blk.blku_u16
539 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
540 #define blk_format      cx_u.cx_blk.blk_u.blku_format
541 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
542 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
543 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
544
545 /* Enter a block. */
546 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
547         cx->cx_type             = t,                                    \
548         cx->blk_oldsp           = sp - PL_stack_base,                   \
549         cx->blk_oldcop          = PL_curcop,                            \
550         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
551         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
552         cx->blk_oldpm           = PL_curpm,                             \
553         cx->blk_gimme           = (U8)gimme;                            \
554         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
555                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
556
557 /* Exit a block (RETURN and LAST). */
558 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
559         newsp            = PL_stack_base + cx->blk_oldsp,               \
560         PL_curcop        = cx->blk_oldcop,                              \
561         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
562         PL_scopestack_ix = cx->blk_oldscopesp,                          \
563         pm               = cx->blk_oldpm,                               \
564         gimme            = cx->blk_gimme;                               \
565         DEBUG_SCOPE("POPBLOCK");                                        \
566         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
567                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
568
569 /* Continue a block elsewhere (NEXT and REDO). */
570 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
571         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
572         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
573         PL_scopestack_ix = cx->blk_oldscopesp,                          \
574         PL_curpm         = cx->blk_oldpm;                               \
575         DEBUG_SCOPE("TOPBLOCK");
576
577 /* substitution context */
578 struct subst {
579     U8          sbu_type;       /* what kind of context this is */
580     U8          sbu_rflags;
581     U16         sbu_rxtainted;  /* matches struct block */
582     I32         sbu_iters;
583     I32         sbu_maxiters;
584     I32         sbu_oldsave;
585     char *      sbu_orig;
586     SV *        sbu_dstr;
587     SV *        sbu_targ;
588     char *      sbu_s;
589     char *      sbu_m;
590     char *      sbu_strend;
591     void *      sbu_rxres;
592     REGEXP *    sbu_rx;
593 };
594 #define sb_iters        cx_u.cx_subst.sbu_iters
595 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
596 #define sb_rflags       cx_u.cx_subst.sbu_rflags
597 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
598 #define sb_once         cx_u.cx_subst.sbu_once
599 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
600 #define sb_orig         cx_u.cx_subst.sbu_orig
601 #define sb_dstr         cx_u.cx_subst.sbu_dstr
602 #define sb_targ         cx_u.cx_subst.sbu_targ
603 #define sb_s            cx_u.cx_subst.sbu_s
604 #define sb_m            cx_u.cx_subst.sbu_m
605 #define sb_strend       cx_u.cx_subst.sbu_strend
606 #define sb_rxres        cx_u.cx_subst.sbu_rxres
607 #define sb_rx           cx_u.cx_subst.sbu_rx
608
609 #ifdef PERL_CORE
610 #  define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],               \
611         cx->sb_iters            = iters,                                \
612         cx->sb_maxiters         = maxiters,                             \
613         cx->sb_rflags           = r_flags,                              \
614         cx->sb_oldsave          = oldsave,                              \
615         cx->sb_rxtainted        = rxtainted,                            \
616         cx->sb_orig             = orig,                                 \
617         cx->sb_dstr             = dstr,                                 \
618         cx->sb_targ             = targ,                                 \
619         cx->sb_s                = s,                                    \
620         cx->sb_m                = m,                                    \
621         cx->sb_strend           = strend,                               \
622         cx->sb_rxres            = NULL,                                 \
623         cx->sb_rx               = rx,                                   \
624         cx->cx_type             = CXt_SUBST | (once ? CXp_ONCE : 0);    \
625         rxres_save(&cx->sb_rxres, rx);                                  \
626         (void)ReREFCNT_inc(rx)
627
628 #  define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                     \
629         rxres_free(&cx->sb_rxres);                                      \
630         ReREFCNT_dec(cx->sb_rx)
631 #endif
632
633 #define CxONCE(cx)              ((cx)->cx_type & CXp_ONCE)
634
635 struct context {
636     union {
637         struct block    cx_blk;
638         struct subst    cx_subst;
639     } cx_u;
640 };
641 #define cx_type cx_u.cx_subst.sbu_type
642
643 /* If you re-order these, there is also an array of uppercase names in perl.h
644    and a static array of context names in pp_ctl.c  */
645 #define CXTYPEMASK      0xf
646 #define CXt_NULL        0
647 #define CXt_WHEN        1
648 #define CXt_BLOCK       2
649 /* When micro-optimising :-) keep GIVEN next to the LOOPs, as these 5 share a
650    jump table in pp_ctl.c
651    The first 4 don't have a 'case' in at least one switch statement in pp_ctl.c
652 */
653 #define CXt_GIVEN       3
654 /* This is first so that CXt_LOOP_FOR|CXt_LOOP_LAZYIV is CXt_LOOP_LAZYIV */
655 #define CXt_LOOP_FOR    4
656 #define CXt_LOOP_PLAIN  5
657 #define CXt_LOOP_LAZYSV 6
658 #define CXt_LOOP_LAZYIV 7
659 #define CXt_SUB         8
660 #define CXt_FORMAT      9
661 #define CXt_EVAL       10
662 #define CXt_SUBST      11
663 /* SUBST doesn't feature in all switch statements.  */
664
665 /* private flags for CXt_SUB and CXt_NULL
666    However, this is checked in many places which do not check the type, so
667    this bit needs to be kept clear for most everything else. For reasons I
668    haven't investigated, it can coexist with CXp_FOR_DEF */
669 #define CXp_MULTICALL   0x10    /* part of a multicall (so don't
670                                    tear down context on exit). */ 
671
672 /* private flags for CXt_SUB and CXt_FORMAT */
673 #define CXp_HASARGS     0x20
674
675 /* private flags for CXt_EVAL */
676 #define CXp_REAL        0x20    /* truly eval'', not a lookalike */
677 #define CXp_TRYBLOCK    0x40    /* eval{}, not eval'' or similar */
678
679 /* private flags for CXt_LOOP */
680 #define CXp_FOR_DEF     0x10    /* foreach using $_ */
681 #ifdef USE_ITHREADS
682 #  define CxPADLOOP(c)  ((c)->blk_loop.targoffset)
683 #endif
684
685 /* private flags for CXt_SUBST */
686 #define CXp_ONCE        0x10    /* What was sbu_once in struct subst */
687
688 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
689 #define CxTYPE_is_LOOP(c)       (((c)->cx_type & 0xC) == 0x4)
690 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
691                          == CXp_MULTICALL)
692 #define CxREALEVAL(c)   (((c)->cx_type & (CXTYPEMASK|CXp_REAL))         \
693                          == (CXt_EVAL|CXp_REAL))
694 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXTYPEMASK|CXp_TRYBLOCK))     \
695                          == (CXt_EVAL|CXp_TRYBLOCK))
696 #define CxFOREACH(c)    (CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN)
697 #define CxFOREACHDEF(c) ((CxTYPE_is_LOOP(c) && CxTYPE(c) != CXt_LOOP_PLAIN) \
698                          && ((c)->cx_type & CXp_FOR_DEF))
699
700 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
701
702 /* 
703 =head1 "Gimme" Values
704 */
705
706 /*
707 =for apidoc AmU||G_SCALAR
708 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
709 L<perlcall>.
710
711 =for apidoc AmU||G_ARRAY
712 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
713 L<perlcall>.
714
715 =for apidoc AmU||G_VOID
716 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
717
718 =for apidoc AmU||G_DISCARD
719 Indicates that arguments returned from a callback should be discarded.  See
720 L<perlcall>.
721
722 =for apidoc AmU||G_EVAL
723
724 Used to force a Perl C<eval> wrapper around a callback.  See
725 L<perlcall>.
726
727 =for apidoc AmU||G_NOARGS
728
729 Indicates that no arguments are being sent to a callback.  See
730 L<perlcall>.
731
732 =cut
733 */
734
735 #define G_SCALAR        2
736 #define G_ARRAY         3
737 #define G_VOID          1
738 #define G_WANT          3
739
740 /* extra flags for Perl_call_* routines */
741 #define G_DISCARD       4       /* Call FREETMPS.
742                                    Don't change this without consulting the
743                                    hash actions codes defined in hv.h */
744 #define G_EVAL          8       /* Assume eval {} around subroutine call. */
745 #define G_NOARGS       16       /* Don't construct a @_ array. */
746 #define G_KEEPERR      32       /* Append errors to $@, don't overwrite it */
747 #define G_NODEBUG      64       /* Disable debugging at toplevel.  */
748 #define G_METHOD      128       /* Calling method. */
749 #define G_FAKINGEVAL  256       /* Faking an eval context for call_sv or
750                                    fold_constants. */
751
752 /* flag bits for PL_in_eval */
753 #define EVAL_NULL       0       /* not in an eval */
754 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
755 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
756 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
757 #define EVAL_INREQUIRE  8       /* The code is being required. */
758
759 /* Support for switching (stack and block) contexts.
760  * This ensures magic doesn't invalidate local stack and cx pointers.
761  */
762
763 #define PERLSI_UNKNOWN          -1
764 #define PERLSI_UNDEF            0
765 #define PERLSI_MAIN             1
766 #define PERLSI_MAGIC            2
767 #define PERLSI_SORT             3
768 #define PERLSI_SIGNAL           4
769 #define PERLSI_OVERLOAD         5
770 #define PERLSI_DESTROY          6
771 #define PERLSI_WARNHOOK         7
772 #define PERLSI_DIEHOOK          8
773 #define PERLSI_REQUIRE          9
774
775 struct stackinfo {
776     AV *                si_stack;       /* stack for current runlevel */
777     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
778     struct stackinfo *  si_prev;
779     struct stackinfo *  si_next;
780     I32                 si_cxix;        /* current context index */
781     I32                 si_cxmax;       /* maximum allocated index */
782     I32                 si_type;        /* type of runlevel */
783     I32                 si_markoff;     /* offset where markstack begins for us.
784                                          * currently used only with DEBUGGING,
785                                          * but not #ifdef-ed for bincompat */
786 };
787
788 typedef struct stackinfo PERL_SI;
789
790 #define cxstack         (PL_curstackinfo->si_cxstack)
791 #define cxstack_ix      (PL_curstackinfo->si_cxix)
792 #define cxstack_max     (PL_curstackinfo->si_cxmax)
793
794 #ifdef DEBUGGING
795 #  define       SET_MARK_OFFSET \
796     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
797 #else
798 #  define       SET_MARK_OFFSET NOOP
799 #endif
800
801 #define PUSHSTACKi(type) \
802     STMT_START {                                                        \
803         PERL_SI *next = PL_curstackinfo->si_next;                       \
804         if (!next) {                                                    \
805             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
806             next->si_prev = PL_curstackinfo;                            \
807             PL_curstackinfo->si_next = next;                            \
808         }                                                               \
809         next->si_type = type;                                           \
810         next->si_cxix = -1;                                             \
811         AvFILLp(next->si_stack) = 0;                                    \
812         SWITCHSTACK(PL_curstack,next->si_stack);                        \
813         PL_curstackinfo = next;                                         \
814         SET_MARK_OFFSET;                                                \
815     } STMT_END
816
817 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
818
819 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
820  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
821 #define POPSTACK \
822     STMT_START {                                                        \
823         dSP;                                                            \
824         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
825         if (!prev) {                                                    \
826             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
827             my_exit(1);                                                 \
828         }                                                               \
829         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
830         /* don't free prev here, free them all at the END{} */          \
831         PL_curstackinfo = prev;                                         \
832     } STMT_END
833
834 #define POPSTACK_TO(s) \
835     STMT_START {                                                        \
836         while (PL_curstack != s) {                                      \
837             dounwind(-1);                                               \
838             POPSTACK;                                                   \
839         }                                                               \
840     } STMT_END
841
842 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
843 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
844
845 /*
846 =head1 Multicall Functions
847
848 =for apidoc Ams||dMULTICALL
849 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
850
851 =for apidoc Ams||PUSH_MULTICALL
852 Opening bracket for a lightweight callback.
853 See L<perlcall/Lightweight Callbacks>.
854
855 =for apidoc Ams||MULTICALL
856 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
857
858 =for apidoc Ams||POP_MULTICALL
859 Closing bracket for a lightweight callback.
860 See L<perlcall/Lightweight Callbacks>.
861
862 =cut
863 */
864
865 #define dMULTICALL \
866     SV **newsp;                 /* set by POPBLOCK */                   \
867     PERL_CONTEXT *cx;                                                   \
868     CV *multicall_cv;                                                   \
869     OP *multicall_cop;                                                  \
870     bool multicall_oldcatch;                                            \
871     U8 hasargs = 0              /* used by PUSHSUB */
872
873 #define PUSH_MULTICALL(the_cv) \
874     STMT_START {                                                        \
875         CV * const _nOnclAshIngNamE_ = the_cv;                          \
876         CV * const cv = _nOnclAshIngNamE_;                              \
877         AV * const padlist = CvPADLIST(cv);                             \
878         ENTER;                                                          \
879         multicall_oldcatch = CATCH_GET;                                 \
880         SAVETMPS; SAVEVPTR(PL_op);                                      \
881         CATCH_SET(TRUE);                                                \
882         PUSHSTACKi(PERLSI_SORT);                                        \
883         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
884         PUSHSUB(cx);                                                    \
885         if (++CvDEPTH(cv) >= 2) {                                       \
886             PERL_STACK_OVERFLOW_CHECK();                                \
887             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
888         }                                                               \
889         SAVECOMPPAD();                                                  \
890         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
891         multicall_cv = cv;                                              \
892         multicall_cop = CvSTART(cv);                                    \
893     } STMT_END
894
895 #define MULTICALL \
896     STMT_START {                                                        \
897         PL_op = multicall_cop;                                          \
898         CALLRUNOPS(aTHX);                                               \
899     } STMT_END
900
901 #define POP_MULTICALL \
902     STMT_START {                                                        \
903         LEAVESUB(multicall_cv);                                         \
904         CvDEPTH(multicall_cv)--;                                        \
905         POPBLOCK(cx,PL_curpm);                                          \
906         POPSTACK;                                                       \
907         CATCH_SET(multicall_oldcatch);                                  \
908         LEAVE;                                                          \
909         SPAGAIN;                                                        \
910     } STMT_END
911
912 /*
913  * Local variables:
914  * c-indentation-style: bsd
915  * c-basic-offset: 4
916  * indent-tabs-mode: t
917  * End:
918  *
919  * ex: set ts=8 sts=4 sw=4 noet:
920  */