TODO
[perl.git] / cop.h
1 /*    cop.h
2  *
3  *    Copyright (c) 1991-1999, Larry Wall
4  *
5  *    You may distribute under the terms of either the GNU General Public
6  *    License or the Artistic License, as specified in the README file.
7  *
8  */
9
10 struct cop {
11     BASEOP
12     char *      cop_label;      /* label for this construct */
13     HV *        cop_stash;      /* package line was compiled in */
14     GV *        cop_filegv;     /* file the following line # is from */
15     U32         cop_seq;        /* parse sequence number */
16     I32         cop_arybase;    /* array base this line was compiled with */
17     line_t      cop_line;       /* line # of this command */
18 };
19
20 #define Nullcop Null(COP*)
21
22 /*
23  * Here we have some enormously heavy (or at least ponderous) wizardry.
24  */
25
26 /* subroutine context */
27 struct block_sub {
28     CV *        cv;
29     GV *        gv;
30     GV *        dfoutgv;
31 #ifndef USE_THREADS
32     AV *        savearray;
33 #endif /* USE_THREADS */
34     AV *        argarray;
35     U16         olddepth;
36     U8          hasargs;
37 };
38
39 #define PUSHSUB(cx)                                                     \
40         cx->blk_sub.cv = cv;                                            \
41         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
42         cx->blk_sub.hasargs = hasargs;
43
44 #define PUSHFORMAT(cx)                                                  \
45         cx->blk_sub.cv = cv;                                            \
46         cx->blk_sub.gv = gv;                                            \
47         cx->blk_sub.hasargs = 0;                                        \
48         cx->blk_sub.dfoutgv = PL_defoutgv;                              \
49         (void)SvREFCNT_inc(cx->blk_sub.dfoutgv)
50
51 #define POPSUB(cx)                                                      \
52         { struct block_sub cxsub;                                       \
53           POPSUB1(cx);                                                  \
54           POPSUB2(); }
55
56 #define POPSUB1(cx)                                                     \
57         cxsub = cx->blk_sub;    /* because DESTROY may clobber *cx */
58
59 #ifdef USE_THREADS
60 #define POPSAVEARRAY() NOOP
61 #else
62 #define POPSAVEARRAY()                                                  \
63     STMT_START {                                                        \
64         SvREFCNT_dec(GvAV(PL_defgv));                                   \
65         GvAV(PL_defgv) = cxsub.savearray;                                       \
66     } STMT_END
67 #endif /* USE_THREADS */
68
69 #define POPSUB2()                                                       \
70         if (cxsub.hasargs) {                                            \
71             POPSAVEARRAY();                                             \
72             /* destroy arg array */                                     \
73             av_clear(cxsub.argarray);                                   \
74             AvREAL_off(cxsub.argarray);                                 \
75             AvREIFY_on(cxsub.argarray);                                 \
76         }                                                               \
77         if (cxsub.cv) {                                                 \
78             if (!(CvDEPTH(cxsub.cv) = cxsub.olddepth))                  \
79                 SvREFCNT_dec(cxsub.cv);                                 \
80         }
81
82 #define POPFORMAT(cx)                                                   \
83         setdefout(cx->blk_sub.dfoutgv);                                 \
84         SvREFCNT_dec(cx->blk_sub.dfoutgv);
85
86 /* eval context */
87 struct block_eval {
88     I32         old_in_eval;
89     I32         old_op_type;
90     char *      old_name;
91     OP *        old_eval_root;
92     SV *        cur_text;
93 };
94
95 #define PUSHEVAL(cx,n,fgv)                                              \
96         cx->blk_eval.old_in_eval = PL_in_eval;                          \
97         cx->blk_eval.old_op_type = PL_op->op_type;                              \
98         cx->blk_eval.old_name = n;                                      \
99         cx->blk_eval.old_eval_root = PL_eval_root;                              \
100         cx->blk_eval.cur_text = PL_linestr;
101
102 #define POPEVAL(cx)                                                     \
103         PL_in_eval = cx->blk_eval.old_in_eval;                          \
104         optype = cx->blk_eval.old_op_type;                              \
105         PL_eval_root = cx->blk_eval.old_eval_root;
106
107 /* loop context */
108 struct block_loop {
109     char *      label;
110     I32         resetsp;
111     OP *        redo_op;
112     OP *        next_op;
113     OP *        last_op;
114     SV **       itervar;
115     SV *        itersave;
116     SV *        iterlval;
117     AV *        iterary;
118     IV          iterix;
119     IV          itermax;
120 };
121
122 #define PUSHLOOP(cx, ivar, s)                                           \
123         cx->blk_loop.label = PL_curcop->cop_label;                              \
124         cx->blk_loop.resetsp = s - PL_stack_base;                               \
125         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
126         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
127         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
128         if (cx->blk_loop.itervar = (ivar))                              \
129             cx->blk_loop.itersave = SvREFCNT_inc(*cx->blk_loop.itervar);\
130         cx->blk_loop.iterlval = Nullsv;                                 \
131         cx->blk_loop.iterary = Nullav;                                  \
132         cx->blk_loop.iterix = -1;
133
134 #define POPLOOP(cx)                                                     \
135         { struct block_loop cxloop;                                     \
136           POPLOOP1(cx);                                                 \
137           POPLOOP2(); }
138
139 #define POPLOOP1(cx)                                                    \
140         cxloop = cx->blk_loop;  /* because DESTROY may clobber *cx */   \
141         newsp = PL_stack_base + cxloop.resetsp;
142
143 #define POPLOOP2()                                                      \
144         SvREFCNT_dec(cxloop.iterlval);                                  \
145         if (cxloop.itervar) {                                           \
146             sv_2mortal(*cxloop.itervar);                                \
147             *cxloop.itervar = cxloop.itersave;                          \
148         }                                                               \
149         if (cxloop.iterary && cxloop.iterary != PL_curstack)            \
150             SvREFCNT_dec(cxloop.iterary);
151
152 /* context common to subroutines, evals and loops */
153 struct block {
154     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
155     COP *       blku_oldcop;    /* old curcop pointer */
156     I32         blku_oldretsp;  /* return stack index */
157     I32         blku_oldmarksp; /* mark stack index */
158     I32         blku_oldscopesp;        /* scope stack index */
159     PMOP *      blku_oldpm;     /* values of pattern match vars */
160     U8          blku_gimme;     /* is this block running in list context? */
161
162     union {
163         struct block_sub        blku_sub;
164         struct block_eval       blku_eval;
165         struct block_loop       blku_loop;
166     } blk_u;
167 };
168 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
169 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
170 #define blk_oldretsp    cx_u.cx_blk.blku_oldretsp
171 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
172 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
173 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
174 #define blk_gimme       cx_u.cx_blk.blku_gimme
175 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
176 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
177 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
178
179 /* Enter a block. */
180 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
181         cx->cx_type             = t,                                    \
182         cx->blk_oldsp           = sp - PL_stack_base,                   \
183         cx->blk_oldcop          = PL_curcop,                            \
184         cx->blk_oldmarksp       = PL_markstack_ptr - PL_markstack,      \
185         cx->blk_oldscopesp      = PL_scopestack_ix,                     \
186         cx->blk_oldretsp        = PL_retstack_ix,                       \
187         cx->blk_oldpm           = PL_curpm,                             \
188         cx->blk_gimme           = gimme;                                \
189         DEBUG_l( PerlIO_printf(PerlIO_stderr(), "Entering block %ld, type %s\n",        \
190                     (long)cxstack_ix, block_type[CxTYPE(cx)]); )
191
192 /* Exit a block (RETURN and LAST). */
193 #define POPBLOCK(cx,pm) cx = &cxstack[cxstack_ix--],                    \
194         newsp            = PL_stack_base + cx->blk_oldsp,               \
195         PL_curcop        = cx->blk_oldcop,                              \
196         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
197         PL_scopestack_ix = cx->blk_oldscopesp,                          \
198         PL_retstack_ix   = cx->blk_oldretsp,                            \
199         pm               = cx->blk_oldpm,                               \
200         gimme            = cx->blk_gimme;                               \
201         DEBUG_l( PerlIO_printf(PerlIO_stderr(), "Leaving block %ld, type %s\n",         \
202                     (long)cxstack_ix+1,block_type[CxTYPE(cx)]); )
203
204 /* Continue a block elsewhere (NEXT and REDO). */
205 #define TOPBLOCK(cx) cx  = &cxstack[cxstack_ix],                        \
206         PL_stack_sp      = PL_stack_base + cx->blk_oldsp,               \
207         PL_markstack_ptr = PL_markstack + cx->blk_oldmarksp,            \
208         PL_scopestack_ix = cx->blk_oldscopesp,                          \
209         PL_retstack_ix   = cx->blk_oldretsp,                            \
210         PL_curpm         = cx->blk_oldpm
211
212 /* substitution context */
213 struct subst {
214     I32         sbu_iters;
215     I32         sbu_maxiters;
216     I32         sbu_safebase;
217     I32         sbu_oldsave;
218     bool        sbu_once;
219     bool        sbu_rxtainted;
220     char *      sbu_orig;
221     SV *        sbu_dstr;
222     SV *        sbu_targ;
223     char *      sbu_s;
224     char *      sbu_m;
225     char *      sbu_strend;
226     void *      sbu_rxres;
227     REGEXP *    sbu_rx;
228 };
229 #define sb_iters        cx_u.cx_subst.sbu_iters
230 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
231 #define sb_safebase     cx_u.cx_subst.sbu_safebase
232 #define sb_oldsave      cx_u.cx_subst.sbu_oldsave
233 #define sb_once         cx_u.cx_subst.sbu_once
234 #define sb_rxtainted    cx_u.cx_subst.sbu_rxtainted
235 #define sb_orig         cx_u.cx_subst.sbu_orig
236 #define sb_dstr         cx_u.cx_subst.sbu_dstr
237 #define sb_targ         cx_u.cx_subst.sbu_targ
238 #define sb_s            cx_u.cx_subst.sbu_s
239 #define sb_m            cx_u.cx_subst.sbu_m
240 #define sb_strend       cx_u.cx_subst.sbu_strend
241 #define sb_rxres        cx_u.cx_subst.sbu_rxres
242 #define sb_rx           cx_u.cx_subst.sbu_rx
243
244 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
245         cx->sb_iters            = iters,                                \
246         cx->sb_maxiters         = maxiters,                             \
247         cx->sb_safebase         = safebase,                             \
248         cx->sb_oldsave          = oldsave,                              \
249         cx->sb_once             = once,                                 \
250         cx->sb_rxtainted        = rxtainted,                            \
251         cx->sb_orig             = orig,                                 \
252         cx->sb_dstr             = dstr,                                 \
253         cx->sb_targ             = targ,                                 \
254         cx->sb_s                = s,                                    \
255         cx->sb_m                = m,                                    \
256         cx->sb_strend           = strend,                               \
257         cx->sb_rxres            = Null(void*),                          \
258         cx->sb_rx               = rx,                                   \
259         cx->cx_type             = CXt_SUBST;                            \
260         rxres_save(&cx->sb_rxres, rx)
261
262 #define POPSUBST(cx) cx = &cxstack[cxstack_ix--];                       \
263         rxres_free(&cx->sb_rxres)
264
265 struct context {
266     U32         cx_type;        /* what kind of context this is */
267     union {
268         struct block    cx_blk;
269         struct subst    cx_subst;
270     } cx_u;
271 };
272
273 #define CXTYPEMASK      0xff
274 #define CXt_NULL        0
275 #define CXt_SUB         1
276 #define CXt_EVAL        2
277 #define CXt_LOOP        3
278 #define CXt_SUBST       4
279 #define CXt_BLOCK       5
280
281 /* private flags for CXt_EVAL */
282 #define CXp_REAL        0x00000100      /* truly eval'', not a lookalike */
283
284 #define CxTYPE(c)       ((c)->cx_type & CXTYPEMASK)
285 #define CxREALEVAL(c)   (((c)->cx_type & (CXt_EVAL|CXp_REAL)) == (CXt_EVAL|CXp_REAL))
286
287 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
288
289 /* "gimme" values */
290 #define G_SCALAR        0
291 #define G_ARRAY         1
292 #define G_VOID          128     /* skip this bit when adding flags below */
293
294 /* extra flags for perl_call_* routines */
295 #define G_DISCARD       2       /* Call FREETMPS. */
296 #define G_EVAL          4       /* Assume eval {} around subroutine call. */
297 #define G_NOARGS        8       /* Don't construct a @_ array. */
298 #define G_KEEPERR      16       /* Append errors to $@, don't overwrite it */
299 #define G_NODEBUG      32       /* Disable debugging at toplevel.  */
300
301 /* Support for switching (stack and block) contexts.
302  * This ensures magic doesn't invalidate local stack and cx pointers.
303  */
304
305 #define PERLSI_UNKNOWN          -1
306 #define PERLSI_UNDEF            0
307 #define PERLSI_MAIN             1
308 #define PERLSI_MAGIC            2
309 #define PERLSI_SORT             3
310 #define PERLSI_SIGNAL           4
311 #define PERLSI_OVERLOAD         5
312 #define PERLSI_DESTROY          6
313 #define PERLSI_WARNHOOK         7
314 #define PERLSI_DIEHOOK          8
315 #define PERLSI_REQUIRE          9
316
317 struct stackinfo {
318     AV *                si_stack;       /* stack for current runlevel */
319     PERL_CONTEXT *      si_cxstack;     /* context stack for runlevel */
320     I32                 si_cxix;        /* current context index */
321     I32                 si_cxmax;       /* maximum allocated index */
322     I32                 si_type;        /* type of runlevel */
323     struct stackinfo *  si_prev;
324     struct stackinfo *  si_next;
325     I32 *               si_markbase;    /* where markstack begins for us.
326                                          * currently used only with DEBUGGING,
327                                          * but not #ifdef-ed for bincompat */
328 };
329
330 typedef struct stackinfo PERL_SI;
331
332 #define cxstack         (PL_curstackinfo->si_cxstack)
333 #define cxstack_ix      (PL_curstackinfo->si_cxix)
334 #define cxstack_max     (PL_curstackinfo->si_cxmax)
335
336 #ifdef DEBUGGING
337 #  define       SET_MARKBASE PL_curstackinfo->si_markbase = PL_markstack_ptr
338 #else
339 #  define       SET_MARKBASE NOOP
340 #endif
341
342 #define PUSHSTACKi(type) \
343     STMT_START {                                                        \
344         PERL_SI *next = PL_curstackinfo->si_next;                       \
345         if (!next) {                                                    \
346             next = new_stackinfo(32, 2048/sizeof(PERL_CONTEXT) - 1);    \
347             next->si_prev = PL_curstackinfo;                            \
348             PL_curstackinfo->si_next = next;                            \
349         }                                                               \
350         next->si_type = type;                                           \
351         next->si_cxix = -1;                                             \
352         AvFILLp(next->si_stack) = 0;                                    \
353         SWITCHSTACK(PL_curstack,next->si_stack);                        \
354         PL_curstackinfo = next;                                         \
355         SET_MARKBASE;                                                   \
356     } STMT_END
357
358 #define PUSHSTACK PUSHSTACKi(PERLSI_UNKNOWN)
359
360 #define POPSTACK \
361     STMT_START {                                                        \
362         PERL_SI *prev = PL_curstackinfo->si_prev;                       \
363         if (!prev) {                                                    \
364             PerlIO_printf(PerlIO_stderr(), "panic: POPSTACK\n");        \
365             my_exit(1);                                                 \
366         }                                                               \
367         SWITCHSTACK(PL_curstack,prev->si_stack);                        \
368         /* don't free prev here, free them all at the END{} */          \
369         PL_curstackinfo = prev;                                         \
370     } STMT_END
371
372 #define POPSTACK_TO(s) \
373     STMT_START {                                                        \
374         while (PL_curstack != s) {                                      \
375             dounwind(-1);                                               \
376             POPSTACK;                                                   \
377         }                                                               \
378     } STMT_END