perl 5.0 alpha 6
[perl.git] / cop.h
1 /* $RCSfile: cmd.h,v $$Revision: 4.1 $$Date: 92/08/07 17:19:19 $
2  *
3  *    Copyright (c) 1991, 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  * $Log:        cmd.h,v $
9  * Revision 4.1  92/08/07  17:19:19  lwall
10  * Stage 6 Snapshot
11  * 
12  * Revision 4.0.1.2  92/06/08  12:01:02  lwall
13  * patch20: removed implicit int declarations on funcions
14  * 
15  * Revision 4.0.1.1  91/06/07  10:28:50  lwall
16  * patch4: new copyright notice
17  * patch4: length($`), length($&), length($') now optimized to avoid string copy
18  * 
19  * Revision 4.0  91/03/20  01:04:34  lwall
20  * 4.0 baseline.
21  * 
22  */
23
24 struct acop {
25     GV          *acop_gv;       /* a symbol table entry */
26     OP          *acop_expr;     /* any associated expression */
27 };
28
29 struct ccop {
30     OP          *ccop_true;     /* normal code to do on if and while */
31     OP          *ccop_alt;      /* else cmd ptr or continue code */
32 };
33
34 struct scop {
35     OP          **scop_next;    /* array of pointers to commands */
36     short       scop_offset;    /* first value - 1 */
37     short       scop_max;       /* last value + 1 */
38 };
39
40 struct cop {
41     BASEOP
42     OP          *cop_expr;      /* conditional expression */
43     OP          *cop_head;      /* head of this command list */
44     SV          *cop_short;     /* string to match as shortcut */
45     GV          *cop_gv;        /* a symbol table entry, mostly for fp */
46     char        *cop_label;     /* label for this construct */
47     union uop {
48         struct acop acop;       /* normal command */
49         struct ccop ccop;       /* compound command */
50         struct scop scop;       /* switch command */
51     } uop;
52     U32         cop_seq;        /* parse sequence number */
53     short       cop_slen;       /* len of cop_short, if not null */
54     VOL short   cop_flags;      /* optimization flags--see above */
55     HV *        cop_stash;      /* package line was compiled in */
56     GV *        cop_filegv;     /* file the following line # is from */
57     line_t      cop_line;       /* line # of this command */
58     char        cop_type;       /* what this command does */
59 };
60
61 #define Nullcop Null(COP*)
62
63 /*
64  * Here we have some enormously heavy (or at least ponderous) wizardry.
65  */
66
67 /* subroutine context */
68 struct block_sub {
69     CV *        cv;
70     GV *        gv;
71     GV *        dfoutgv;
72     AV *        savearray;
73     AV *        argarray;
74     U16         olddepth;
75     U8          hasargs;
76 };
77
78 #define PUSHSUB(cx)                                                     \
79         cx->blk_sub.cv = cv;                                            \
80         cx->blk_sub.olddepth = CvDEPTH(cv);                             \
81         cx->blk_sub.hasargs = hasargs;
82
83 #define PUSHFORMAT(cx)                                                  \
84         cx->blk_sub.cv = cv;                                            \
85         cx->blk_sub.gv = gv;                                            \
86         cx->blk_sub.dfoutgv = defoutgv;                                 \
87         cx->blk_sub.hasargs = 0;
88
89 #define POPSUB(cx)                                                      \
90         if (cx->blk_sub.hasargs) {   /* put back old @_ */              \
91             GvAV(defgv) = cx->blk_sub.savearray;                        \
92         }                                                               \
93         if (cx->blk_sub.cv) {                                           \
94             if (!(CvDEPTH(cx->blk_sub.cv) = cx->blk_sub.olddepth)) {    \
95                 if (CvDELETED(cx->blk_sub.cv))                          \
96                     SvREFCNT_dec((SV*)cx->blk_sub.cv);                  \
97             }                                                           \
98         }
99
100 #define POPFORMAT(cx)                                                   \
101         defoutgv = cx->blk_sub.dfoutgv;
102
103 /* eval context */
104 struct block_eval {
105     I32         old_in_eval;
106     I32         old_op_type;
107     char *      old_name;
108     OP *        old_eval_root;
109 };
110
111 #define PUSHEVAL(cx,n,fgv)                                              \
112         cx->blk_eval.old_in_eval = in_eval;                             \
113         cx->blk_eval.old_op_type = op->op_type;                         \
114         cx->blk_eval.old_name = n;                                      \
115         cx->blk_eval.old_eval_root = eval_root;
116
117 #define POPEVAL(cx)                                                     \
118         in_eval = cx->blk_eval.old_in_eval;                             \
119         optype = cx->blk_eval.old_op_type;                              \
120         eval_root = cx->blk_eval.old_eval_root;
121
122 /* loop context */
123 struct block_loop {
124     char *      label;
125     I32         resetsp;
126     OP *        redo_op;
127     OP *        next_op;
128     OP *        last_op;
129     SV **       itervar;
130     SV *        itersave;
131     AV *        iterary;
132     I32         iterix;
133 };
134
135 #define PUSHLOOP(cx, ivar, s)                                           \
136         cx->blk_loop.label = curcop->cop_label;                         \
137         cx->blk_loop.resetsp = s - stack_base;                          \
138         cx->blk_loop.redo_op = cLOOP->op_redoop;                        \
139         cx->blk_loop.next_op = cLOOP->op_nextop;                        \
140         cx->blk_loop.last_op = cLOOP->op_lastop;                        \
141         cx->blk_loop.itervar = ivar;                                    \
142         if (ivar)                                                       \
143             cx->blk_loop.itersave = *cx->blk_loop.itervar;
144
145 #define POPLOOP(cx)                                                     \
146         newsp           = stack_base + cx->blk_loop.resetsp;            \
147         if (cx->blk_loop.itervar)                                       \
148             *cx->blk_loop.itervar = cx->blk_loop.itersave;
149
150 /* context common to subroutines, evals and loops */
151 struct block {
152     I32         blku_oldsp;     /* stack pointer to copy stuff down to */
153     COP *       blku_oldcop;    /* old curcop pointer */
154     I32         blku_oldretsp;  /* return stack index */
155     I32         blku_oldmarksp; /* mark stack index */
156     I32         blku_oldscopesp;        /* scope stack index */
157     PMOP *      blku_oldpm;     /* values of pattern match vars */
158     U8          blku_gimme;     /* is this block running in list context? */
159
160     union {
161         struct block_sub        blku_sub;
162         struct block_eval       blku_eval;
163         struct block_loop       blku_loop;
164     } blk_u;
165 };
166 #define blk_oldsp       cx_u.cx_blk.blku_oldsp
167 #define blk_oldcop      cx_u.cx_blk.blku_oldcop
168 #define blk_oldretsp    cx_u.cx_blk.blku_oldretsp
169 #define blk_oldmarksp   cx_u.cx_blk.blku_oldmarksp
170 #define blk_oldscopesp  cx_u.cx_blk.blku_oldscopesp
171 #define blk_oldpm       cx_u.cx_blk.blku_oldpm
172 #define blk_gimme       cx_u.cx_blk.blku_gimme
173 #define blk_sub         cx_u.cx_blk.blk_u.blku_sub
174 #define blk_eval        cx_u.cx_blk.blk_u.blku_eval
175 #define blk_loop        cx_u.cx_blk.blk_u.blku_loop
176
177 /* Enter a block. */
178 #define PUSHBLOCK(cx,t,sp) CXINC, cx = &cxstack[cxstack_ix],            \
179         cx->cx_type             = t,                                    \
180         cx->blk_oldsp           = sp - stack_base,                      \
181         cx->blk_oldcop          = curcop,                               \
182         cx->blk_oldmarksp       = markstack_ptr - markstack,            \
183         cx->blk_oldscopesp      = scopestack_ix,                        \
184         cx->blk_oldretsp        = retstack_ix,                          \
185         cx->blk_oldpm           = curpm,                                \
186         cx->blk_gimme           = gimme;                                \
187         DEBUG_l( fprintf(stderr,"Entering block %d, type %s\n",         \
188                     cxstack_ix, block_type[t]); )
189
190 /* Exit a block (RETURN and LAST). */
191 #define POPBLOCK(cx) cx = &cxstack[cxstack_ix--],                       \
192         newsp           = stack_base + cx->blk_oldsp,                   \
193         curcop          = cx->blk_oldcop,                               \
194         markstack_ptr   = markstack + cx->blk_oldmarksp,                \
195         scopestack_ix   = cx->blk_oldscopesp,                           \
196         retstack_ix     = cx->blk_oldretsp,                             \
197         curpm           = cx->blk_oldpm,                                \
198         gimme           = cx->blk_gimme;                                \
199         DEBUG_l( fprintf(stderr,"Leaving block %d, type %s\n",          \
200                     cxstack_ix+1,block_type[cx->cx_type]); )
201
202 /* Continue a block elsewhere (NEXT and REDO). */
203 #define TOPBLOCK(cx) cx = &cxstack[cxstack_ix],                         \
204         stack_sp        = stack_base + cx->blk_oldsp,                   \
205         markstack_ptr   = markstack + cx->blk_oldmarksp,                \
206         scopestack_ix   = cx->blk_oldscopesp,                           \
207         retstack_ix     = cx->blk_oldretsp
208
209 /* substitution context */
210 struct subst {
211     I32         sbu_iters;
212     I32         sbu_maxiters;
213     I32         sbu_safebase;
214     I32         sbu_once;
215     char *      sbu_orig;
216     SV *        sbu_dstr;
217     SV *        sbu_targ;
218     char *      sbu_s;
219     char *      sbu_m;
220     char *      sbu_strend;
221     char *      sbu_subbase;
222 };
223 #define sb_iters        cx_u.cx_subst.sbu_iters
224 #define sb_maxiters     cx_u.cx_subst.sbu_maxiters
225 #define sb_safebase     cx_u.cx_subst.sbu_safebase
226 #define sb_once         cx_u.cx_subst.sbu_once
227 #define sb_orig         cx_u.cx_subst.sbu_orig
228 #define sb_dstr         cx_u.cx_subst.sbu_dstr
229 #define sb_targ         cx_u.cx_subst.sbu_targ
230 #define sb_s            cx_u.cx_subst.sbu_s
231 #define sb_m            cx_u.cx_subst.sbu_m
232 #define sb_strend       cx_u.cx_subst.sbu_strend
233 #define sb_subbase      cx_u.cx_subst.sbu_subbase
234
235 #define PUSHSUBST(cx) CXINC, cx = &cxstack[cxstack_ix],                 \
236         cx->sb_iters            = iters,                                \
237         cx->sb_maxiters         = maxiters,                             \
238         cx->sb_safebase         = safebase,                             \
239         cx->sb_once             = once,                                 \
240         cx->sb_orig             = orig,                                 \
241         cx->sb_dstr             = dstr,                                 \
242         cx->sb_targ             = targ,                                 \
243         cx->sb_s                = s,                                    \
244         cx->sb_m                = m,                                    \
245         cx->sb_strend           = strend,                               \
246         cx->cx_type             = CXt_SUBST
247
248 #define POPSUBST(cx) cxstack_ix--
249
250 struct context {
251     I32         cx_type;        /* what kind of context this is */
252     union {
253         struct block    cx_blk;
254         struct subst    cx_subst;
255     } cx_u;
256 };
257 #define CXt_NULL        0
258 #define CXt_SUB         1
259 #define CXt_EVAL        2
260 #define CXt_LOOP        3
261 #define CXt_SUBST       4
262 #define CXt_BLOCK       5
263
264 #define CXINC (cxstack_ix < cxstack_max ? ++cxstack_ix : (cxstack_ix = cxinc()))
265
266 /* "gimme" values */
267 #define G_SCALAR 0
268 #define G_ARRAY 1
269