2 * Empire - A multi-player, client/server Internet based war game.
3 * Copyright (C) 1986-2005, Dave Pare, Jeff Bailey, Thomas Ruschak,
4 * Ken Stevens, Steve McClure
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
23 * related information and legal notices. It is expected that any future
24 * projects/authors will amend these files as needed.
28 * nstr.c: compile and execute the item selections on sectors
30 * Known contributors to this file:
33 * Markus Armbruster, 2004
41 #include "prototypes.h"
43 static char *nstr_parse_val(char *, struct valstr *);
44 static int nstr_match_ca(struct valstr *, struct castr *);
45 static int nstr_match_val(struct valstr *, int, struct castr *, int);
46 static int nstr_string_ok(struct castr *ca, int idx);
47 static struct valstr *nstr_resolve_sel(struct valstr *, struct castr *);
48 static struct valstr *nstr_mkselval(struct valstr *, int, struct castr *);
49 static struct valstr *nstr_resolve_id(struct valstr *, struct castr *, int, int);
50 static int nstr_promote(int);
54 * Compile conditions into array NP[LEN].
55 * Return number of conditions, or -1 on error.
56 * It is an error if there are more than LEN conditions.
57 * TYPE is the context type, a file type.
58 * STR is the condition string, in Empire syntax, without the leading
62 nstr_comp(struct nscstr *np, int len, int type, char *str)
64 struct castr *ca = ef_cadef(type);
69 int lft_caidx, rgt_caidx;
71 int lft_type, rgt_type;
74 for (i = 0; ; ++i, ++np) {
79 tail = nstr_parse_val(cond, &np->lft);
80 lft_caidx = nstr_match_ca(&np->lft, ca);
83 if (*tail != '<' && *tail != '=' && *tail != '>' && *tail != '#') {
85 pr("%s -- expected condition operator\n", cond);
87 pr("%s -- missing condition operator\n", cond);
94 tail = nstr_parse_val(tail, &np->rgt);
95 rgt_caidx = nstr_match_ca(&np->rgt, ca);
100 * An identifier can name a selector or, if the other operand
101 * is a selector, a value for that. The condition is
102 * ambiguous if both selector x value and value x selector are
103 * possible. Example: n<n for sectors could mean newdes<n or
106 lft_val = nstr_match_val(&np->lft, type, ca, rgt_caidx);
107 rgt_val = nstr_match_val(&np->rgt, type, ca, lft_caidx);
109 * if lft_val >= 0, then rhs names a selector and lhs names
110 * one of its values. Likewise for rgt_val.
112 if (lft_val >= 0 && rgt_val >= 0) {
113 pr("%.*s -- condition ambiguous\n", (int)(tail-cond), cond);
115 } else if (rgt_val >= 0) {
116 /* selector x value */
117 if (!nstr_resolve_sel(&np->lft, &ca[lft_caidx]))
119 nstr_mkselval(&np->rgt, rgt_val, &ca[lft_caidx]);
120 } else if (lft_val >= 0) {
121 /* value x selector */
122 nstr_mkselval(&np->lft, lft_val, &ca[rgt_caidx]);
123 if (!nstr_resolve_sel(&np->rgt, &ca[rgt_caidx]))
127 * Neither side works as selector value; any identifiers
128 * must name selectors.
130 if (!nstr_resolve_id(&np->lft, ca, lft_caidx,
131 nstr_string_ok(ca, rgt_caidx)))
133 if (!nstr_resolve_id(&np->rgt, ca, rgt_caidx,
134 nstr_string_ok(ca, lft_caidx)))
138 /* find operator type, coerce operands */
139 lft_type = nstr_promote(np->lft.val_type);
140 rgt_type = nstr_promote(np->rgt.val_type);
141 np->optype = NSC_NOTYPE;
142 if (lft_type == NSC_TYPEID) {
143 if (!nstr_coerce_val(&np->rgt, NSC_TYPEID, str))
144 np->optype = NSC_TYPEID;
145 } else if (rgt_type == NSC_TYPEID) {
146 if (!nstr_coerce_val(&np->lft, NSC_TYPEID, str))
147 np->optype = NSC_TYPEID;
148 } else if (lft_type == NSC_STRING) {
149 if (!nstr_coerce_val(&np->rgt, NSC_STRING, str))
150 np->optype = NSC_STRING;
151 } else if (rgt_type == NSC_STRING) {
152 if (!nstr_coerce_val(&np->lft, NSC_STRING, str))
153 np->optype = NSC_STRING;
154 } else if (lft_type == NSC_DOUBLE) {
155 if (!nstr_coerce_val(&np->rgt, NSC_DOUBLE, str))
156 np->optype = NSC_DOUBLE;
157 } else if (rgt_type == NSC_DOUBLE) {
158 if (!nstr_coerce_val(&np->lft, NSC_DOUBLE, str))
159 np->optype = NSC_DOUBLE;
161 if (!nstr_coerce_val(&np->lft, NSC_LONG, str)
162 && !nstr_coerce_val(&np->rgt, NSC_LONG, str))
163 np->optype = NSC_LONG;
165 if (np->optype == NSC_NOTYPE)
168 /* another condition? */
172 pr("%s -- expected `&'\n", cond);
179 /* could just return I and let caller gripe or enlarge buffer */
180 pr("%s -- too many conditions\n", str);
187 /* Like strcmp(S1, S2), but limit length of S1 to SZ1 and of S2 to SZ2. */
189 strnncmp(char *s1, size_t sz1, char *s2, size_t sz2)
192 if (sz1 == sz2) return strncmp(s1, s2, sz2);
193 if (sz1 < sz2) return -strnncmp(s2, sz2, s1, sz1);
194 res = strncmp(s1, s2, sz2);
195 return res ? res : s1[sz2];
198 #define EVAL(op, lft, rgt) \
199 ((op) == '<' ? (lft) < (rgt) \
200 : (op) == '=' ? (lft) == (rgt) \
201 : (op) == '>' ? (lft) > (rgt) \
202 : (op) == '#' ? (lft) != (rgt) \
206 * Evaluate compiled conditions in array NP[NCOND].
207 * Return non-zero iff they are all true.
208 * PTR points to a context object of the type that was used to compile
212 nstr_exec(struct nscstr *np, int ncond, void *ptr)
214 int i, op, optype, cmp;
215 struct valstr lft, rgt;
217 for (i = 0; i < ncond; ++i) {
219 optype = np[i].optype;
220 if (np[i].lft.val_cat == NSC_NOCAT || np[i].rgt.val_cat == NSC_NOCAT)
223 nstr_exec_val(&lft, player->cnum, ptr, optype);
225 nstr_exec_val(&rgt, player->cnum, ptr, optype);
229 if (!EVAL(op, lft.val_as.lng, rgt.val_as.lng))
233 if (!EVAL(op, lft.val_as.dbl, rgt.val_as.dbl))
237 cmp = strnncmp(lft.val_as.str.base, lft.val_as.str.maxsz,
238 rgt.val_as.str.base, rgt.val_as.str.maxsz);
239 if (!EVAL(op, cmp, 0))
243 CANT_HAPPEN("bad OPTYPE");
252 * Parse a value in STR into VAL.
253 * Return a pointer to the first character after the value.
254 * Value is either evaluated (but not NSC_TYPEID) or an identifier.
257 nstr_parse_val(char *str, struct valstr *val)
264 if (str[0] == '\'') {
265 for (tail = str + 1; *tail && *tail != '\''; ++tail) ;
266 /* FIXME implement \ quoting */
267 val->val_type = NSC_STRING;
268 val->val_cat = NSC_VAL;
269 val->val_as.str.base = str + 1;
270 val->val_as.str.maxsz = tail - (str + 1);
276 if (isalpha(str[0])) {
277 for (tail = str+1; isalnum(*tail) || *tail == '_'; ++tail) ;
278 val->val_type = NSC_NOTYPE;
279 val->val_cat = NSC_ID;
280 val->val_as.str.base = str;
281 val->val_as.str.maxsz = tail - str;
286 l = strtol(str, &tail, 0);
287 d = strtod(str, &tail2);
289 val->val_type = NSC_DOUBLE;
290 val->val_cat = NSC_VAL;
295 val->val_type = NSC_LONG;
296 val->val_cat = NSC_VAL;
301 /* funny character, interpret as identifier */
303 val->val_type = NSC_NOTYPE;
304 val->val_cat = NSC_ID;
305 val->val_as.str.base = str;
306 val->val_as.str.maxsz = tail - str;
311 * Match VAL in table of selector descriptors CA, return index.
312 * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
314 * A VAL that is not an identifier doesn't match anything. A null CA
315 * is considered empty.
318 nstr_match_ca(struct valstr *val, struct castr *ca)
322 if (val->val_cat != NSC_ID || val->val_as.str.maxsz >= sizeof(id))
328 memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
329 id[val->val_as.str.maxsz] = 0;
331 return stmtch(id, ca, offsetof(struct castr, ca_name),
332 sizeof(struct castr));
336 * Match VAL in a selector's values, return its (non-negative) value.
337 * TYPE is the context type, a file type.
338 * CA is ef_cadef(TYPE). If it is null, then IDX must be negative.
339 * Match values of selector descriptor CA[IDX], provided IDX is not
341 * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
343 * TODO: This is just a stub and works only for NSC_TYPEID.
344 * Generalize: give struct castr enough info to find values, remove
348 nstr_match_val(struct valstr *val, int type, struct castr *ca, int idx)
352 if (val->val_cat != NSC_ID || val->val_as.str.maxsz >= sizeof(id))
355 if (idx < 0 || ca[idx].ca_type != NSC_TYPEID)
358 memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
359 id[val->val_as.str.maxsz] = 0;
361 return typematch(id, type);
365 * Can CA[IDX] be compared to a string?
366 * Return 0 for negative IDX.
369 nstr_string_ok(struct castr *ca, int idx)
371 return idx >= 0 && nstr_promote(ca[idx].ca_type) == NSC_STRING;
375 * Change VAL to resolve identifier to selector or string.
376 * Return VAL on success, NULL on error.
377 * No change if VAL is not an identifier. Otherwise, change it as
379 * Error if IDX == M_NOTUNIQUE or IDX == M_NOTFOUND and !STRING_OK.
380 * Change into string if IDX == M_NOTFOUND and STRING_OK.
381 * Change into selector CA[IDX] if IDX >= 0.
383 static struct valstr *
384 nstr_resolve_id(struct valstr *val, struct castr *ca, int idx, int string_ok)
386 if (val->val_cat != NSC_ID)
389 if (idx == M_NOTUNIQUE) {
390 pr("%.*s -- ambiguous name\n",
391 (int)val->val_as.str.maxsz, val->val_as.str.base);
392 val->val_cat = NSC_NOCAT;
397 CANT_HAPPEN(idx != M_NOTFOUND);
399 pr("%.*s -- unknown name\n",
400 (int)val->val_as.str.maxsz, val->val_as.str.base);
401 val->val_cat = NSC_NOCAT;
404 /* interpret unbound identifier as string */
405 val->val_type = NSC_STRING;
406 val->val_cat = NSC_VAL;
410 return nstr_resolve_sel(val, &ca[idx]);
414 * Change VAL to resolve identifier to selector CA.
415 * Return VAL on success, NULL if the player is denied access to the
417 * VAL must be an identifier.
419 static struct valstr *
420 nstr_resolve_sel(struct valstr *val, struct castr *ca)
422 if (CANT_HAPPEN(val->val_cat != NSC_ID)) {
423 val->val_cat = NSC_NOCAT;
427 if ((ca->ca_flags & NSC_DEITY) && !player->god) {
428 pr("%.*s -- not accessible to mortals\n",
429 (int)val->val_as.str.maxsz, val->val_as.str.base);
430 val->val_cat = NSC_NOCAT;
434 val->val_type = ca->ca_type;
435 val->val_cat = NSC_OFF;
436 val->val_as.sym.off = ca->ca_off;
437 val->val_as.sym.len = ca->ca_len;
438 val->val_as.sym.idx = 0;
443 * Initialize VAL to value SELVAL for selector CA, return VAL.
445 static struct valstr *
446 nstr_mkselval(struct valstr *val, int selval, struct castr *ca)
448 if (CANT_HAPPEN(ca->ca_type != NSC_TYPEID)) {
449 val->val_type = NSC_NOTYPE;
450 val->val_cat = NSC_NOCAT;
454 val->val_type = ca->ca_type;
455 val->val_cat = NSC_VAL;
456 val->val_as.lng = selval;
461 * Compile a value in STR into VAL.
462 * Return a pointer to the first character after the value on success,
464 * TYPE is the context type, a file type.
465 * If STR names an array, VAL simply refers to the element with index
469 nstr_comp_val(char *str, struct valstr *val, int type)
471 struct castr *ca = ef_cadef(type);
472 char *tail = nstr_parse_val(str, val);
473 return nstr_resolve_id(val, ca, nstr_match_ca(val, ca), 0) ? tail : NULL;
479 * If VALTYPE is an integer type, return NSC_LONG.
480 * If VALTYPE is a floating-point type, return NSC_DOUBLE.
481 * If VALTYPE is NSC_STRINGY, return NSC_STRING.
482 * If VALTYPE is NSC_NOTYPE, NSC_STRING or NSC_TYPEID, return VALTYPE.
485 nstr_promote(int valtype)
505 valtype = NSC_DOUBLE;
508 valtype = NSC_STRING;
511 CANT_HAPPEN("bad VALTYPE");
512 valtype = NSC_NOTYPE;
518 cond_type_mismatch(char *str)
521 pr("%s -- condition operand type mismatch\n", str);
526 * Coerce VAL to promoted value type TO.
527 * Return 0 on success, -1 on error.
528 * If VAL is evaluated, convert it, else only check.
529 * STR is the condition text to be used for error messages. Suppress
530 * messages if it is a null pointer.
533 nstr_coerce_val(struct valstr *val, nsc_type to, char *str)
535 /* FIXME get rid of promotion? */
536 nsc_type from = nstr_promote(val->val_type);
538 if (from == NSC_NOTYPE)
544 return cond_type_mismatch(str);
546 return cond_type_mismatch(str); /* FIXME implement */
548 if (from == NSC_LONG) {
549 if (val->val_cat == NSC_VAL)
550 val->val_as.dbl = val->val_as.lng;
552 return cond_type_mismatch(str);
555 return cond_type_mismatch(str);
557 CANT_HAPPEN("bad TO argument");
562 if (val->val_cat == NSC_VAL) {
563 /* coord literals don't occur, conversion not implemented */
564 CANT_HAPPEN(val->val_type == NSC_XCOORD
565 || val->val_type == NSC_YCOORD);
574 * If VAL is symbolic, evaluate it into a promoted value type.
575 * Use coordinate system of country CNUM.
576 * PTR points to a context object of the type that was used to compile
578 * Unless WANT is NSC_NOTYPE, coerce the value to promoted value type
579 * WANT. VAL must be coercible. That's the case if a previous
580 * nstr_coerce_val(VAL, WANT, STR) succeeded.
583 nstr_exec_val(struct valstr *val, natid cnum, void *ptr, nsc_type want)
589 switch (val->val_cat) {
591 CANT_HAPPEN("Bad VAL category");
594 valtype = val->val_type;
599 memb_ptr += val->val_as.sym.off;
600 idx = val->val_as.sym.idx;
601 switch (val->val_type) {
603 val->val_as.lng = ((signed char *)memb_ptr)[idx];
606 val->val_as.lng = ((unsigned char *)memb_ptr)[idx];
609 val->val_as.lng = ((short *)memb_ptr)[idx];
612 val->val_as.lng = ((unsigned short *)memb_ptr)[idx];
615 val->val_as.lng = ((int *)memb_ptr)[idx];
618 val->val_as.lng = ((long *)memb_ptr)[idx];
621 val->val_as.lng = xrel(getnatp(cnum), ((short *)memb_ptr)[idx]);
624 val->val_as.lng = yrel(getnatp(cnum), ((short *)memb_ptr)[idx]);
627 val->val_as.dbl = ((float *)memb_ptr)[idx];
628 valtype = NSC_DOUBLE;
631 val->val_as.dbl = ((double *)memb_ptr)[idx];
632 valtype = NSC_DOUBLE;
636 val->val_as.str.maxsz = val->val_as.sym.len;
637 val->val_as.str.base = (char *)memb_ptr;
638 valtype = NSC_STRING;
641 val->val_as.str.base = ((char **)memb_ptr)[idx];
642 val->val_as.str.maxsz = INT_MAX;
643 valtype = NSC_STRING;
646 val->val_as.lng = ((time_t *)memb_ptr)[idx];
649 val->val_as.lng = ((signed char *)memb_ptr)[idx];
650 valtype = NSC_TYPEID;
653 CANT_HAPPEN("Bad VAL type");
656 val->val_cat = NSC_VAL;
661 else if (want == NSC_DOUBLE) {
662 if (valtype == NSC_LONG) {
664 val->val_as.dbl = val->val_as.lng;
666 } else if (want == NSC_STRING)
667 CANT_HAPPEN("unimplemented WANT"); /* FIXME */
669 if (CANT_HAPPEN(valtype != want && want != NSC_NOTYPE)) {
673 case NSC_LONG: val->val_as.lng = 0; break;
674 case NSC_DOUBLE: val->val_as.dbl = 0.0; break;
675 case NSC_STRING: val->val_as.str.base = NULL; break;
677 CANT_HAPPEN("bad WANT argument");
681 val->val_type = valtype;
685 symbol_by_value(int key, struct symbol *table)
689 for (i = 0; table[i].name; i++)
690 if (key == table[i].value)
691 return table[i].name;