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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 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
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_hints;      /* hints bits from pragmata */
147     U32         cop_seq;        /* parse sequence number */
148     line_t      cop_line;       /* line # of this command */
149     /* Beware. mg.c and warnings.pl assume the type of this is STRLEN *:  */
150     STRLEN *    cop_warnings;   /* lexical warnings bitmask */
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_hash;
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 /* If $[ is non-zero, it's stored in cop_hints under the key "$[", and
233    HINT_ARYBASE is set to indicate this.
234    Setting it is ineficient due to the need to create 2 mortal SVs, but as
235    using $[ is highly discouraged, no sane Perl code will be using it.  */
236 #define CopARYBASE_get(c)       \
237         ((CopHINTS_get(c) & HINT_ARYBASE)                               \
238          ? SvIV(Perl_refcounted_he_fetch(aTHX_ (c)->cop_hints_hash, 0,  \
239                                          "$[", 2, 0, 0))                \
240          : 0)
241 #define CopARYBASE_set(c, b) STMT_START { \
242         if (b || ((c)->cop_hints & HINT_ARYBASE)) {                     \
243             (c)->cop_hints |= HINT_ARYBASE;                             \
244             if ((c) == &PL_compiling)                                   \
245                 PL_hints |= HINT_LOCALIZE_HH | HINT_ARYBASE;            \
246             (c)->cop_hints_hash                                         \
247                = Perl_refcounted_he_new(aTHX_ (c)->cop_hints_hash,      \
248                                         sv_2mortal(newSVpvs("$[")),     \
249                                         sv_2mortal(newSViv(b)));        \
250         }                                                               \
251     } STMT_END
252
253 /* FIXME NATIVE_HINTS if this is changed from op_private (see perl.h)  */
254 #define CopHINTS_get(c)         ((c)->cop_hints + 0)
255 #define CopHINTS_set(c, h)      STMT_START {                            \
256                                     (c)->cop_hints = (h);               \
257                                 } STMT_END
258
259 /*
260  * Here we have some enormously heavy (or at least ponderous) wizardry.
261  */
262
263 /* subroutine context */
264 struct block_sub {
265     CV *        cv;
266     GV *        gv;
267     GV *        dfoutgv;
268     AV *        savearray;
269     AV *        argarray;
270     I32         olddepth;
271     /* These are merged to to get struct context down to 64 bytes on ILP32.  */
272     U8          hasargs_lval;
273     PAD         *oldcomppad;
274     OP *        retop;  /* op to execute on exit from sub */
275 };
276
277 #define CX_SUB_HASARGS_SET(cx, v)       ((cx)->blk_sub.hasargs_lval = \
278  ((cx)->blk_sub.hasargs_lval & 0xFE) | ((v) ? 1 : 0))
279 #define CX_SUB_HASARGS_GET(cx)          ((cx)->blk_sub.hasargs_lval & 0x01)
280
281 #define CX_SUB_LVAL_SET(cx, v)          ((cx)->blk_sub.hasargs_lval = \
282  (((cx)->blk_sub.hasargs_lval & 0x01) | ((v) & (OPpLVAL_INTRO|OPpENTERSUB_INARGS))))
283 #define CX_SUB_LVAL(cx)                 ((cx)->blk_sub.hasargs_lval & 0xFE)
284 #define CX_SUB_LVAL_INARGS(cx)          ((cx)->blk_sub.hasargs_lval & \
285                                          OPpENTERSUB_INARGS)
286
287 /* base for the next two macros. Don't use directly.
288  * Note that the refcnt of the cv is incremented twice;  The CX one is
289  * decremented by LEAVESUB, the other by LEAVE. */
290
291 #define PUSHSUB_BASE(cx)                                                \
292         cx->blk_sub.cv = cv;                                            \
293         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
294         CX_SUB_HASARGS_SET(cx, hasargs);                                \
295         cx->blk_sub.retop = NULL;                                       \
296         if (!CvDEPTH(cv)) {                                             \
297             SvREFCNT_inc_simple_void_NN(cv);                            \
298             SvREFCNT_inc_simple_void_NN(cv);                            \
299             SAVEFREESV(cv);                                             \
300         }
301
302
303 #define PUSHSUB(cx)                                                     \
304         PUSHSUB_BASE(cx)                                                \
305         CX_SUB_LVAL_SET(cx, PL_op->op_private)
306
307 /* variant for use by OP_DBSTATE, where op_private holds hint bits */
308 #define PUSHSUB_DB(cx)                                                  \
309         PUSHSUB_BASE(cx)                                                \
310         CX_SUB_LVAL_SET(cx, 0)
311
312
313 #define PUSHFORMAT(cx)                                                  \
314         cx->blk_sub.cv = cv;                                            \
315         cx->blk_sub.gv = gv;                                            \
316         cx->blk_sub.retop = NULL;                                       \
317         CX_SUB_HASARGS_SET(cx, 0);                                      \
318         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
319         SvREFCNT_inc_void(cx->blk_sub.dfoutgv)
320
321 #define POP_SAVEARRAY()                                         \
322     STMT_START {                                                        \
323         SvREFCNT_dec(GvAV(PL_defgv));                                   \
324         GvAV(PL_defgv) = cx->blk_sub.savearray;                         \
325     } STMT_END
326
327 /* junk in @_ spells trouble when cloning CVs and in pp_caller(), so don't
328  * leave any (a fast av_clear(ary), basically) */
329 #define CLEAR_ARGARRAY(ary) \
330     STMT_START {                                                        \
331         AvMAX(ary) += AvARRAY(ary) - AvALLOC(ary);                      \
332         SvPV_set(ary, (char*)AvALLOC(ary));                             \
333         AvFILLp(ary) = -1;                                              \
334     } STMT_END
335
336 #define POPSUB(cx,sv)                                                   \
337     STMT_START {                                                        \
338         if (CX_SUB_HASARGS_GET(cx)) {                                   \
339             POP_SAVEARRAY();                                            \
340             /* abandon @_ if it got reified */                          \
341             if (AvREAL(cx->blk_sub.argarray)) {                         \
342                 const SSize_t fill = AvFILLp(cx->blk_sub.argarray);     \
343                 SvREFCNT_dec(cx->blk_sub.argarray);                     \
344                 cx->blk_sub.argarray = newAV();                         \
345                 av_extend(cx->blk_sub.argarray, fill);                  \
346                 AvREIFY_only(cx->blk_sub.argarray);                     \
347                 CX_CURPAD_SV(cx->blk_sub, 0) = (SV*)cx->blk_sub.argarray;       \
348             }                                                           \
349             else {                                                      \
350                 CLEAR_ARGARRAY(cx->blk_sub.argarray);                   \
351             }                                                           \
352         }                                                               \
353         sv = (SV*)cx->blk_sub.cv;                                       \
354         if (sv && (CvDEPTH((CV*)sv) = cx->blk_sub.olddepth))            \
355             sv = NULL;                                          \
356     } STMT_END
357
358 #define LEAVESUB(sv)                                                    \
359     STMT_START {                                                        \
360         if (sv)                                                         \
361             SvREFCNT_dec(sv);                                           \
362     } STMT_END
363
364 #define POPFORMAT(cx)                                                   \
365         setdefout(cx->blk_sub.dfoutgv);                                 \
366         SvREFCNT_dec(cx->blk_sub.dfoutgv);
367
368 /* eval context */
369 struct block_eval {
370     I32         old_in_eval;
371     I32         old_op_type;
372     SV *        old_namesv;
373     OP *        old_eval_root;
374     SV *        cur_text;
375     CV *        cv;
376     OP *        retop;  /* op to execute on exit from eval */
377     JMPENV *    cur_top_env; /* value of PL_top_env when eval CX created */
378 };
379
380 #define PUSHEVAL(cx,n,fgv)                                              \
381     STMT_START {                                                        \
382         cx->blk_eval.old_in_eval = PL_in_eval;                          \
383         cx->blk_eval.old_op_type = PL_op->op_type;                      \
384         cx->blk_eval.old_namesv = (n ? newSVpv(n,0) : NULL);            \
385         cx->blk_eval.old_eval_root = PL_eval_root;                      \
386         cx->blk_eval.cur_text = PL_linestr;                             \
387         cx->blk_eval.cv = NULL; /* set by doeval(), as applicable */    \
388         cx->blk_eval.retop = NULL;                                      \
389         cx->blk_eval.cur_top_env = PL_top_env;                          \
390     } STMT_END
391
392 #define POPEVAL(cx)                                                     \
393     STMT_START {                                                        \
394         PL_in_eval = cx->blk_eval.old_in_eval;                          \
395         optype = cx->blk_eval.old_op_type;                              \
396         PL_eval_root = cx->blk_eval.old_eval_root;                      \
397         if (cx->blk_eval.old_namesv)                                    \
398             sv_2mortal(cx->blk_eval.old_namesv);                        \
399     } STMT_END
400
401 /* loop context */
402 struct block_loop {
403     char *      label;
404     I32         resetsp;
405     OP *        redo_op;
406     OP *        next_op;
407     OP *        last_op;
408 #ifdef USE_ITHREADS
409     void *      iterdata;
410     PAD         *oldcomppad;
411 #else
412     SV **       itervar;
413 #endif
414     SV *        itersave;
415     SV *        iterlval;
416     AV *        iterary;
417     IV          iterix;
418     IV          itermax;
419 };
420
421 #ifdef USE_ITHREADS
422 #  define CxITERVAR(c)                                                  \
423         ((c)->blk_loop.iterdata                                         \
424          ? (CxPADLOOP(cx)                                               \
425             ? &CX_CURPAD_SV( (c)->blk_loop,                             \
426                     INT2PTR(PADOFFSET, (c)->blk_loop.iterdata))         \
427             : &GvSV((GV*)(c)->blk_loop.iterdata))                       \
428          : (SV**)NULL)
429 #  define CX_ITERDATA_SET(cx,idata)                                     \
430         CX_CURPAD_SAVE(cx->blk_loop);                                   \
431         if ((cx->blk_loop.iterdata = (idata)))                          \
432             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
433         else                                                            \
434             cx->blk_loop.itersave = NULL;
435 #else
436 #  define CxITERVAR(c)          ((c)->blk_loop.itervar)
437 #  define CX_ITERDATA_SET(cx,ivar)                                      \
438         if ((cx->blk_loop.itervar = (SV**)(ivar)))                      \
439             cx->blk_loop.itersave = SvREFCNT_inc(*CxITERVAR(cx));       \
440         else                                                            \
441             cx->blk_loop.itersave = NULL;
442 #endif
443
444 #define PUSHLOOP(cx, dat, s)                                            \
445         cx->blk_loop.label = PL_curcop->cop_label;                      \
446         cx->blk_loop.resetsp = s - PL_stack_base;                       \
447         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
448         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
449         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
450         cx->blk_loop.iterlval = NULL;                                   \
451         cx->blk_loop.iterary = NULL;                                    \
452         cx->blk_loop.iterix = -1;                                       \
453         CX_ITERDATA_SET(cx,dat);
454
455 #define POPLOOP(cx)                                                     \
456         SvREFCNT_dec(cx->blk_loop.iterlval);                            \
457         if (CxITERVAR(cx)) {                                            \
458             if (SvPADMY(cx->blk_loop.itersave)) {                       \
459                 SV ** const s_v_p = CxITERVAR(cx);                      \
460                 sv_2mortal(*s_v_p);                                     \
461                 *s_v_p = cx->blk_loop.itersave;                         \
462             }                                                           \
463             else {                                                      \
464                 SvREFCNT_dec(cx->blk_loop.itersave);                    \
465             }                                                           \
466         }                                                               \
467         if (cx->blk_loop.iterary && cx->blk_loop.iterary != PL_curstack)\
468             SvREFCNT_dec(cx->blk_loop.iterary);
469
470 /* given/when context */
471 struct block_givwhen {
472         OP *leave_op;
473 };
474
475 #define PUSHGIVEN(cx)                                                   \
476         cx->blk_givwhen.leave_op = cLOGOP->op_other;
477
478 #define PUSHWHEN PUSHGIVEN
479
480 /* context common to subroutines, evals and loops */
481 struct block {
482     U16         blku_type;      /* what kind of context this is */
483     U8          blku_gimme;     /* is this block running in list context? */
484     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
485     COP *       blku_oldcop;    /* old curcop pointer */
486     I32         blku_oldmarksp; /* mark stack index */
487     I32         blku_oldscopesp;        /* scope stack index */
488     PMOP *      blku_oldpm;     /* values of pattern match vars */
489
490     union {
491         struct block_sub        blku_sub;
492         struct block_eval       blku_eval;
493         struct block_loop       blku_loop;
494         struct block_givwhen    blku_givwhen;
495     } blk_u;
496 };
497 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
498 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
499 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
500 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
501 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
502 #define blk_gimme       cx_u.cx_blk.blku_gimme
503 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
504 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
505 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
506 #define blk_givwhen     cx_u.cx_blk.blk_u.blku_givwhen
507
508 /* Enter a block. */
509 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
510         cx->cx_type             = t,                                    \
511         cx->blk_oldsp           = sp - PL_stack_base,                   \
512         cx->blk_oldcop          = PL_curcop,                            \
513         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
514         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
515         cx->blk_oldpm           = PL_curpm,                             \
516         cx->blk_gimme           = (U8)gimme;                            \
517         DEBUG_l( PerlIO_printf(Perl_debug_log, "Entering block %ld, type %s\n", \
518                     (long)cxstack_ix, PL_block_type[CxTYPE(cx)]); )
519
520 /* Exit a block (RETURN and LAST). */
521 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
522         newsp            = PL_stack_base + cx->blk_oldsp,               \
523         PL_curcop        = cx->blk_oldcop,                              \
524         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
525         PL_scopestack_ix = cx->blk_oldscopesp,                          \
526         pm               = cx->blk_oldpm,                               \
527         gimme            = cx->blk_gimme;                               \
528         DEBUG_SCOPE("POPBLOCK");                                        \
529         DEBUG_l( PerlIO_printf(Perl_debug_log, "Leaving block %ld, type %s\n",          \
530                     (long)cxstack_ix+1,PL_block_type[CxTYPE(cx)]); )
531
532 /* Continue a block elsewhere (NEXT and REDO). */
533 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
534         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
535         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
536         PL_scopestack_ix = cx->blk_oldscopesp,                          \
537         PL_curpm         = cx->blk_oldpm;                               \
538         DEBUG_SCOPE("TOPBLOCK");
539
540 /* substitution context */
541 struct subst {
542     U16         sbu_type;       /* what kind of context this is */
543     bool        sbu_once;
544     bool        sbu_rxtainted;
545     I32         sbu_iters;
546     I32         sbu_maxiters;
547     I32         sbu_rflags;
548     I32         sbu_oldsave;
549     char *      sbu_orig;
550     SV *        sbu_dstr;
551     SV *        sbu_targ;
552     char *      sbu_s;
553     char *      sbu_m;
554     char *      sbu_strend;
555     void *      sbu_rxres;
556     REGEXP *    sbu_rx;
557 };
558 #define sb_iters        cx_u.cx_subst.sbu_iters
559 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
560 #define sb_rflags       cx_u.cx_subst.sbu_rflags
561 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
562 #define sb_once         cx_u.cx_subst.sbu_once
563 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
564 #define sb_orig         cx_u.cx_subst.sbu_orig
565 #define sb_dstr         cx_u.cx_subst.sbu_dstr
566 #define sb_targ         cx_u.cx_subst.sbu_targ
567 #define sb_s            cx_u.cx_subst.sbu_s
568 #define sb_m            cx_u.cx_subst.sbu_m
569 #define sb_strend       cx_u.cx_subst.sbu_strend
570 #define sb_rxres        cx_u.cx_subst.sbu_rxres
571 #define sb_rx           cx_u.cx_subst.sbu_rx
572
573 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
574         cx->sb_iters            = iters,                                \
575         cx->sb_maxiters         = maxiters,                             \
576         cx->sb_rflags           = r_flags,                              \
577         cx->sb_oldsave          = oldsave,                              \
578         cx->sb_once             = once,                                 \
579         cx->sb_rxtainted        = rxtainted,                            \
580         cx->sb_orig             = orig,                                 \
581         cx->sb_dstr             = dstr,                                 \
582         cx->sb_targ             = targ,                                 \
583         cx->sb_s                = s,                                    \
584         cx->sb_m                = m,                                    \
585         cx->sb_strend           = strend,                               \
586         cx->sb_rxres            = NULL,                                 \
587         cx->sb_rx               = rx,                                   \
588         cx->cx_type             = CXt_SUBST;                            \
589         rxres_save(&cx->sb_rxres, rx);                                  \
590         (void)ReREFCNT_inc(rx)
591
592 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
593         rxres_free(&cx->sb_rxres);                                      \
594         ReREFCNT_dec(cx->sb_rx)
595
596 struct context {
597     union {
598         struct block    cx_blk;
599         struct subst    cx_subst;
600     } cx_u;
601 };
602 #define cx_type cx_u.cx_subst.sbu_type
603
604 #define CXTYPEMASK      0xff
605 #define CXt_NULL        0
606 #define CXt_SUB         1
607 #define CXt_EVAL        2
608 #define CXt_LOOP        3
609 #define CXt_SUBST       4
610 #define CXt_BLOCK       5
611 #define CXt_FORMAT      6
612 #define CXt_GIVEN       7
613 #define CXt_WHEN        8
614
615 /* private flags for CXt_SUB and CXt_NULL */
616 #define CXp_MULTICALL   0x00000400      /* part of a multicall (so don't
617                                            tear down context on exit). */ 
618
619 /* private flags for CXt_EVAL */
620 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
621 #define CXp_TRYBLOCK    0x00000200      /* eval{}, not eval'' or similar */
622
623 /* private flags for CXt_LOOP */
624 #define CXp_FOREACH     0x00000200      /* a foreach loop */
625 #define CXp_FOR_DEF     0x00000400      /* foreach using $_ */
626 #ifdef USE_ITHREADS
627 #  define CXp_PADVAR    0x00000100      /* itervar lives on pad, iterdata
628                                            has pad offset; if not set,
629                                            iterdata holds GV* */
630 #  define CxPADLOOP(c)  (((c)->cx_type & (CXt_LOOP|CXp_PADVAR))         \
631                          == (CXt_LOOP|CXp_PADVAR))
632 #endif
633
634 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
635 #define CxMULTICALL(c)  (((c)->cx_type & CXp_MULTICALL)                 \
636                          == CXp_MULTICALL)
637 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL))           \
638                          == (CXt_EVAL|CXp_REAL))
639 #define CxTRYBLOCK(c)   (((c)->cx_type & (CXt_EVAL|CXp_TRYBLOCK))       \
640                          == (CXt_EVAL|CXp_TRYBLOCK))
641 #define CxFOREACH(c)    (((c)->cx_type & (CXt_LOOP|CXp_FOREACH))        \
642                          == (CXt_LOOP|CXp_FOREACH))
643 #define CxFOREACHDEF(c) (((c)->cx_type & (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))\
644                          == (CXt_LOOP|CXp_FOREACH|CXp_FOR_DEF))
645
646 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
647
648 /* 
649 =head1 "Gimme" Values
650 */
651
652 /*
653 =for apidoc AmU||G_SCALAR
654 Used to indicate scalar context.  See C<GIMME_V>, C<GIMME>, and
655 L<perlcall>.
656
657 =for apidoc AmU||G_ARRAY
658 Used to indicate list context.  See C<GIMME_V>, C<GIMME> and
659 L<perlcall>.
660
661 =for apidoc AmU||G_VOID
662 Used to indicate void context.  See C<GIMME_V> and L<perlcall>.
663
664 =for apidoc AmU||G_DISCARD
665 Indicates that arguments returned from a callback should be discarded.  See
666 L<perlcall>.
667
668 =for apidoc AmU||G_EVAL
669
670 Used to force a Perl C<eval> wrapper around a callback.  See
671 L<perlcall>.
672
673 =for apidoc AmU||G_NOARGS
674
675 Indicates that no arguments are being sent to a callback.  See
676 L<perlcall>.
677
678 =cut
679 */
680
681 #define G_SCALAR        0
682 #define G_ARRAY         1
683 #define G_VOID          128     /* skip this bit when adding flags below */
684
685 /* extra flags for Perl_call_* routines */
686 #define G_DISCARD       2       /* Call FREETMPS. */
687 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
688 #define G_NOARGS        8       /* Don't construct a @_ array. */
689 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
690 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
691 #define G_METHOD       64       /* Calling method. */
692 #define G_FAKINGEVAL  256       /* Faking en eval context for call_sv or
693                                    fold_constants. */
694
695 /* flag bits for PL_in_eval */
696 #define EVAL_NULL       0       /* not in an eval */
697 #define EVAL_INEVAL     1       /* some enclosing scope is an eval */
698 #define EVAL_WARNONLY   2       /* used by yywarn() when calling yyerror() */
699 #define EVAL_KEEPERR    4       /* set by Perl_call_sv if G_KEEPERR */
700 #define EVAL_INREQUIRE  8       /* The code is being required. */
701
702 /* Support for switching (stack and block) contexts.
703  * This ensures magic doesn't invalidate local stack and cx pointers.
704  */
705
706 #define PERLSI_UNKNOWN          -1
707 #define PERLSI_UNDEF            0
708 #define PERLSI_MAIN             1
709 #define PERLSI_MAGIC            2
710 #define PERLSI_SORT             3
711 #define PERLSI_SIGNAL           4
712 #define PERLSI_OVERLOAD         5
713 #define PERLSI_DESTROY          6
714 #define PERLSI_WARNHOOK         7
715 #define PERLSI_DIEHOOK          8
716 #define PERLSI_REQUIRE          9
717
718 struct stackinfo {
719     AV *                si_stack;       /* stack for current runlevel */
720     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
721     I32                 si_cxix;        /* current context index */
722     I32                 si_cxmax;       /* maximum allocated index */
723     I32                 si_type;        /* type of runlevel */
724     struct stackinfo *  si_prev;
725     struct stackinfo *  si_next;
726     I32                 si_markoff;     /* offset where markstack begins for us.
727                                          * currently used only with DEBUGGING,
728                                          * but not #ifdef-ed for bincompat */
729 };
730
731 typedef struct stackinfo PERL_SI;
732
733 #define cxstack         (PL_curstackinfo->si_cxstack)
734 #define cxstack_ix      (PL_curstackinfo->si_cxix)
735 #define cxstack_max     (PL_curstackinfo->si_cxmax)
736
737 #ifdef DEBUGGING
738 #  define       SET_MARK_OFFSET \
739     PL_curstackinfo->si_markoff = PL_markstack_ptr - PL_markstack
740 #else
741 #  define       SET_MARK_OFFSET NOOP
742 #endif
743
744 #define PUSHSTACKi(type) \
745     STMT_START {                                                        \
746         PERL_SI *next = PL_curstackinfo->si_next;                       \
747         if (!next) {                                                    \
748             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
749             next->si_prev = PL_curstackinfo;                            \
750             PL_curstackinfo->si_next = next;                            \
751         }                                                               \
752         next->si_type = type;                                           \
753         next->si_cxix = -1;                                             \
754         AvFILLp(next->si_stack) = 0;                                    \
755         SWITCHSTACK(PL_curstack,next->si_stack);                        \
756         PL_curstackinfo = next;                                         \
757         SET_MARK_OFFSET;                                                \
758     } STMT_END
759
760 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
761
762 /* POPSTACK works with PL_stack_sp, so it may need to be bracketed by
763  * PUTBACK/SPAGAIN to flush/refresh any local SP that may be active */
764 #define POPSTACK \
765     STMT_START {                                                        \
766         dSP;                                                            \
767         PERL_SI * const prev = PL_curstackinfo->si_prev;                \
768         if (!prev) {                                                    \
769             PerlIO_printf(Perl_error_log, "panic: POPSTACK\n");         \
770             my_exit(1);                                                 \
771         }                                                               \
772         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
773         /* don't free prev here, free them all at the END{} */          \
774         PL_curstackinfo = prev;                                         \
775     } STMT_END
776
777 #define POPSTACK_TO(s) \
778     STMT_START {                                                        \
779         while (PL_curstack != s) {                                      \
780             dounwind(-1);                                               \
781             POPSTACK;                                                   \
782         }                                                               \
783     } STMT_END
784
785 #define IN_PERL_COMPILETIME     (PL_curcop == &PL_compiling)
786 #define IN_PERL_RUNTIME         (PL_curcop != &PL_compiling)
787
788 /*
789 =head1 Multicall Functions
790
791 =for apidoc Ams||dMULTICALL
792 Declare local variables for a multicall. See L<perlcall/Lightweight Callbacks>.
793
794 =for apidoc Ams||PUSH_MULTICALL
795 Opening bracket for a lightweight callback.
796 See L<perlcall/Lightweight Callbacks>.
797
798 =for apidoc Ams||MULTICALL
799 Make a lightweight callback. See L<perlcall/Lightweight Callbacks>.
800
801 =for apidoc Ams||POP_MULTICALL
802 Closing bracket for a lightweight callback.
803 See L<perlcall/Lightweight Callbacks>.
804
805 =cut
806 */
807
808 #define dMULTICALL \
809     SV **newsp;                 /* set by POPBLOCK */                   \
810     PERL_CONTEXT *cx;                                                   \
811     CV *multicall_cv;                                                   \
812     OP *multicall_cop;                                                  \
813     bool multicall_oldcatch;                                            \
814     U8 hasargs = 0              /* used by PUSHSUB */
815
816 #define PUSH_MULTICALL(the_cv) \
817     STMT_START {                                                        \
818         CV * const _nOnclAshIngNamE_ = the_cv;                          \
819         CV * const cv = _nOnclAshIngNamE_;                              \
820         AV * const padlist = CvPADLIST(cv);                             \
821         ENTER;                                                          \
822         multicall_oldcatch = CATCH_GET;                                 \
823         SAVETMPS; SAVEVPTR(PL_op);                                      \
824         CATCH_SET(TRUE);                                                \
825         PUSHBLOCK(cx, CXt_SUB|CXp_MULTICALL, PL_stack_sp);              \
826         PUSHSUB(cx);                                                    \
827         if (++CvDEPTH(cv) >= 2) {                                       \
828             PERL_STACK_OVERFLOW_CHECK();                                \
829             Perl_pad_push(aTHX_ padlist, CvDEPTH(cv));                  \
830         }                                                               \
831         SAVECOMPPAD();                                                  \
832         PAD_SET_CUR_NOSAVE(padlist, CvDEPTH(cv));                       \
833         multicall_cv = cv;                                              \
834         multicall_cop = CvSTART(cv);                                    \
835     } STMT_END
836
837 #define MULTICALL \
838     STMT_START {                                                        \
839         PL_op = multicall_cop;                                          \
840         CALLRUNOPS(aTHX);                                               \
841     } STMT_END
842
843 #define POP_MULTICALL \
844     STMT_START {                                                        \
845         LEAVESUB(multicall_cv);                                         \
846         CvDEPTH(multicall_cv)--;                                        \
847         POPBLOCK(cx,PL_curpm);                                          \
848         CATCH_SET(multicall_oldcatch);                                  \
849         LEAVE;                                                          \
850     } STMT_END
851
852 /*
853  * Local variables:
854  * c-indentation-style: bsd
855  * c-basic-offset: 4
856  * indent-tabs-mode: t
857  * End:
858  *
859  * ex: set ts=8 sts=4 sw=4 noet:
860  */