/*
* Empire - A multi-player, client/server Internet based war game.
- * Copyright (C) 1986-2000, Dave Pare, Jeff Bailey, Thomas Ruschak,
- * Ken Stevens, Steve McClure
+ * Copyright (C) 1986-2011, Dave Pare, Jeff Bailey, Thomas Ruschak,
+ * Ken Stevens, Steve McClure, Markus Armbruster
*
- * This program is free software; you can redistribute it and/or modify
+ * Empire is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* ---
*
- * See the "LEGAL", "LICENSE", "CREDITS" and "README" files for all the
- * related information and legal notices. It is expected that any future
- * projects/authors will amend these files as needed.
+ * See files README, COPYING and CREDITS in the root of the source
+ * tree for related information and legal notices. It is expected
+ * that future projects/authors will amend these files as needed.
*
* ---
*
* nstr.c: compile and execute the item selections on sectors
- *
+ *
* Known contributors to this file:
* Dave Pare, 1989
* Steve McClure, 1997
+ * Markus Armbruster, 2004-2008
*/
+#include <config.h>
+
#include <ctype.h>
-#include "struct.h"
-#include "misc.h"
-#include "var.h"
-#include "xy.h"
-#include "sect.h"
-#include "nsc.h"
-#include "nat.h"
-#include "match.h"
+#include <limits.h>
#include "file.h"
+#include "match.h"
#include "player.h"
#include "prototypes.h"
-static int legal_val(s_char *str, int val);
+static char *nstr_parse_val(char *, struct valstr *);
+static int nstr_match_ca(struct valstr *, struct castr *);
+static int nstr_is_name_of_ca(struct valstr *, struct castr *, int);
+static int nstr_ca_comparable(struct castr *, int, int);
+static int nstr_match_val(struct valstr *, struct castr *, int);
+static struct valstr *nstr_resolve_id(struct valstr *, struct castr *, int);
+static struct valstr *nstr_resolve_val(struct valstr *, int, struct castr *);
+static int nstr_optype(enum nsc_type, enum nsc_type);
/*
- * Compiles and adds "str" to the list of conditionals.
- * type is the EF typename of the item type we're selecting.
- * returns amount of "str" used by nstr_comp (i.e. how far
- * the pointer was advanced). The last is only meaningful
- * if several conditionals are expected in one string.
+ * Compile conditions into array NP[LEN].
+ * Return number of conditions, or -1 on error.
+ * It is an error if there are more than LEN conditions.
+ * TYPE is the context type, a file type.
+ * STR is the condition string, in Empire syntax, without the leading
+ * '?'.
*/
-s_char *
-nstr_comp(struct nscstr *np, int *size, int type, s_char *str)
+int
+nstr_comp(struct nscstr *np, int len, int type, char *str)
{
- register s_char *bp;
- register s_char *cp;
- register int c;
- s_char ident[80];
- s_char arg[255];
- int op;
- int val;
-
- strncpy(arg, str, sizeof(arg) - 1);
- arg[sizeof(arg) - 1] = 0;
- cp = arg;
- bp = ident;
- while ((c = *cp++) && bp < &ident[sizeof(ident) - 1]) {
- if (c == '<' || c == '=' || c == '>' || c == '#')
+ struct castr *ca = ef_cadef(type);
+ char *cond;
+ char *tail;
+ int i;
+ struct nscstr dummy;
+ int lft_caidx, rgt_caidx;
+ int lft_val, rgt_val;
+ int two_sels;
+
+ cond = str;
+ for (i = 0; ; ++i, ++np) {
+ if (i >= len)
+ np = &dummy;
+
+ /* left operand */
+ tail = nstr_parse_val(cond, &np->lft);
+ lft_caidx = nstr_match_ca(&np->lft, ca);
+
+ /* operator */
+ if (*tail != '<' && *tail != '=' && *tail != '>' && *tail != '#') {
+ if (*tail)
+ pr("%s -- expected condition operator\n", cond);
+ else
+ pr("%s -- missing condition operator\n", cond);
+ return -1;
+ }
+ np->operator = *tail;
+ ++tail;
+
+ /* right operand */
+ tail = nstr_parse_val(tail, &np->rgt);
+ rgt_caidx = nstr_match_ca(&np->rgt, ca);
+
+ /*
+ * Resolve identifiers
+ *
+ * If just one operand is an identifier, it names a selector.
+ * If both operands are identifiers, things get complicated:
+ * either can then name a selector or a symbolic value for the
+ * selector named by the other operand.
+ */
+ if (np->lft.val_cat == NSC_ID && np->rgt.val_cat == NSC_ID) {
+ lft_val = nstr_match_val(&np->lft, ca, rgt_caidx);
+ rgt_val = nstr_match_val(&np->rgt, ca, lft_caidx);
+ two_sels = nstr_ca_comparable(ca, lft_caidx, rgt_caidx);
+ /*
+ * If lft_val >= 0 interpreting rgt as a selector and lft
+ * as one of its values works. Likewise for rgt_val >= 0.
+ * If two_sels, interpreting both lft and rgt as selector
+ * works.
+ */
+ switch ((lft_val >= 0) + (rgt_val >= 0) + !!two_sels) {
+ case 0: /* no interpretation */
+ if (lft_caidx >= 0 && rgt_caidx >= 0) {
+ /*
+ * Both identifiers name selectors. Since
+ * !two_sels, they can't be comparable.
+ * Example: type=civil.
+ */
+ pr("%.*s -- not comparable\n", (int)(tail-cond), cond);
+ return -1;
+ }
+ /*
+ * At least one identifier doesn't name a selector,
+ * and nstr_resolve_id() will fail for it below
+ */
+ break;
+ case 1: /* one unambigous interpretation */
+ break;
+ default: /* multiple interpretations */
+ /*
+ * Last-resort disambiguation: if the identifier is
+ * the unabbreviated name of a selector, discard
+ * value, else discard selector interpretation.
+ * Example: resolve wing=g to wing='g', not wing=group
+ * or 'wing'=group.
+ */
+ if (nstr_is_name_of_ca(&np->lft, ca, lft_caidx))
+ lft_val = -1;
+ else
+ two_sels = 0;
+ if (nstr_is_name_of_ca(&np->rgt, ca, rgt_caidx))
+ rgt_val = -1;
+ else
+ two_sels = 0;
+ if ((lft_val >= 0) + (rgt_val >= 0) + !!two_sels == 1)
+ break; /* last-resort disambiguation worked */
+ /*
+ * Example: n<n for sectors could mean newdes<n or
+ * n<newdes.
+ */
+ pr("%.*s -- condition ambiguous\n", (int)(tail-cond), cond);
+ return -1;
+ }
+ /* resolve identifiers naming values */
+ if (lft_val >= 0)
+ nstr_resolve_val(&np->lft, lft_val, &ca[rgt_caidx]);
+ if (rgt_val >= 0)
+ nstr_resolve_val(&np->rgt, rgt_val, &ca[lft_caidx]);
+ }
+ /* remaining identifiers name selectors */
+ if (!nstr_resolve_id(&np->lft, ca, lft_caidx))
+ return -1;
+ if (!nstr_resolve_id(&np->rgt, ca, rgt_caidx))
+ return -1;
+
+ /* find operator type */
+ np->optype = nstr_optype(np->lft.val_type, np->rgt.val_type);
+ if (np->optype == NSC_NOTYPE) {
+ pr("%.*s -- not comparable\n", (int)(tail-cond), cond);
+ return -1;
+ }
+
+ /* another condition? */
+ if (*tail == 0)
break;
- *bp++ = c;
+ if (*tail != '&') {
+ pr("%s -- expected `&'\n", cond);
+ return -1;
+ }
+ cond = tail + 1;
}
- *bp = 0;
- if (c == 0) {
- pr("'%s'? -- meaningless condition?\n", arg);
- return 0;
+
+ if (i >= len) {
+ /* could just return I and let caller gripe or enlarge buffer */
+ pr("%s -- too many conditions\n", str);
+ return -1;
}
- op = c;
- np[*size].oper = op;
- if ((val = encode(ident, &np[*size].fld1, type)) < 0)
- return 0;
- if (val == 2)
- np[*size].oper += 255;
- bp = ident;
- while ((c = *cp++) && bp < &ident[sizeof(ident) - 1]) {
- if (c == '&')
+
+ return i + 1;
+}
+
+/* Like strcmp(S1, S2), but limit length of S1 to SZ1 and of S2 to SZ2. */
+static int
+strnncmp(char *s1, size_t sz1, char *s2, size_t sz2)
+{
+ int res;
+ if (sz1 == sz2)
+ return strncmp(s1, s2, sz2);
+ if (sz1 < sz2)
+ return -strnncmp(s2, sz2, s1, sz1);
+ res = strncmp(s1, s2, sz2);
+ return res ? res : s1[sz2];
+}
+
+#define EVAL(op, lft, rgt) \
+ ((op) == '<' ? (lft) < (rgt) \
+ : (op) == '=' ? (lft) == (rgt) \
+ : (op) == '>' ? (lft) > (rgt) \
+ : (op) == '#' ? (lft) != (rgt) \
+ : (CANT_REACH(), 0))
+
+/*
+ * Evaluate compiled conditions in array NP[NCOND].
+ * Return non-zero iff they are all true.
+ * PTR points to a context object of the type that was used to compile
+ * the conditions.
+ */
+int
+nstr_exec(struct nscstr *np, int ncond, void *ptr)
+{
+ int i, op, optype, cmp;
+ struct valstr lft, rgt;
+
+ for (i = 0; i < ncond; ++i) {
+ op = np[i].operator;
+ optype = np[i].optype;
+ if (np[i].lft.val_cat == NSC_NOCAT || np[i].rgt.val_cat == NSC_NOCAT)
+ return 0;
+ lft = np[i].lft;
+ nstr_exec_val(&lft, player->cnum, ptr, optype);
+ rgt = np[i].rgt;
+ nstr_exec_val(&rgt, player->cnum, ptr, optype);
+ switch (optype) {
+ case NSC_LONG:
+ if (!EVAL(op, lft.val_as.lng, rgt.val_as.lng))
+ return 0;
+ break;
+ case NSC_DOUBLE:
+ if (!EVAL(op, lft.val_as.dbl, rgt.val_as.dbl))
+ return 0;
break;
- *bp++ = c;
+ case NSC_STRING:
+ cmp = strnncmp(lft.val_as.str.base, lft.val_as.str.maxsz,
+ rgt.val_as.str.base, rgt.val_as.str.maxsz);
+ if (!EVAL(op, cmp, 0))
+ return 0;
+ break;
+ default:
+ CANT_REACH();
+ return 0;
+ }
}
- *bp = 0;
- if ((val = encode(ident, &np[*size].fld2, type)) < 0)
+
+ return 1;
+}
+
+/*
+ * Parse a value in STR into VAL.
+ * Return a pointer to the first character after the value.
+ * Value is either evaluated into NSC_STRING, NSC_DOUBLE or NSC_LONG,
+ * or an identifier.
+ */
+static char *
+nstr_parse_val(char *str, struct valstr *val)
+{
+ long l;
+ double d;
+ char *tail, *tail2;
+
+ /* string */
+ if (str[0] == '\'') {
+ for (tail = str + 1; *tail && *tail != '\''; ++tail) ;
+ /* FIXME implement \ quoting */
+ val->val_type = NSC_STRING;
+ val->val_cat = NSC_VAL;
+ val->val_as.str.base = str + 1;
+ val->val_as.str.maxsz = tail - (str + 1);
+ if (*tail)
+ ++tail;
+ /* FIXME else unclosed string */
+ return tail;
+ }
+
+ /* identifier */
+ if (isalpha(str[0])) {
+ for (tail = str+1; isalnum(*tail) || *tail == '_'; ++tail) ;
+ val->val_type = NSC_NOTYPE;
+ val->val_cat = NSC_ID;
+ val->val_as.str.base = str;
+ val->val_as.str.maxsz = tail - str;
+ return tail;
+ }
+
+ /* number */
+ l = strtol(str, &tail, 0);
+ d = strtod(str, &tail2);
+ if (tail2 > tail) {
+ val->val_type = NSC_DOUBLE;
+ val->val_cat = NSC_VAL;
+ val->val_as.dbl = d;
+ return tail2;
+ }
+ if (tail != str) {
+ val->val_type = NSC_LONG;
+ val->val_cat = NSC_VAL;
+ val->val_as.lng = l;
+ return tail;
+ }
+
+ /* funny character, interpret as identifier */
+ tail = str+1;
+ val->val_type = NSC_NOTYPE;
+ val->val_cat = NSC_ID;
+ val->val_as.str.base = str;
+ val->val_as.str.maxsz = tail - str;
+ return tail;
+}
+
+/*
+ * Match VAL in table of selector descriptors CA, return index.
+ * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
+ * several.
+ * A VAL that is not an identifier doesn't match anything. A null CA
+ * is considered empty.
+ */
+static int
+nstr_match_ca(struct valstr *val, struct castr *ca)
+{
+ char id[32];
+
+ if (val->val_cat != NSC_ID || val->val_as.str.maxsz >= sizeof(id))
+ return M_NOTFOUND;
+
+ if (!ca)
+ return M_NOTFOUND;
+
+ memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
+ id[val->val_as.str.maxsz] = 0;
+
+ return stmtch(id, ca, offsetof(struct castr, ca_name),
+ sizeof(struct castr));
+}
+
+/*
+ * Is identifier VAL the name of the selector given by CA and IDX?
+ * Return non-zero if and only if IDX is non-negative and VAL is the
+ * name of CA[IDX].
+ * IDX must have been obtained from nstr_match_ca(VAL, CA).
+ */
+static int
+nstr_is_name_of_ca(struct valstr *val, struct castr *ca, int idx)
+{
+ if (CANT_HAPPEN(val->val_cat != NSC_ID && idx >= 0))
return 0;
- if (val == 2)
- np[*size].oper += 65535;
- if (c == 0)
- cp--;
- (*size)++;
- return str + (cp - arg);
+ return idx >= 0 && strlen(ca[idx].ca_name) == val->val_as.str.maxsz;
}
-int
-encode(register s_char *str, long int *val, int type)
+/*
+ * Do we have two comparable selectors?
+ * Check selector descriptors CA[LFT_IDX] (unless LFT_IDX is negative)
+ * and CA[RGT_IDX] (unless RGT_IDX is negative). CA may be null when
+ * both are negative.
+ */
+static int
+nstr_ca_comparable(struct castr *ca, int lft_idx, int rgt_idx)
{
- register int i;
- struct castr *cap;
+ if (lft_idx < 0 || rgt_idx < 0)
+ return 0;
+ if (ca[lft_idx].ca_table != ca[rgt_idx].ca_table)
+ return 0; /* Example: land type=spy */
+ return nstr_optype(ca[lft_idx].ca_type, ca[rgt_idx].ca_type)
+ != NSC_NOTYPE; /* Example: ship name=effic */
+}
+
+/*
+ * Match VAL in a selector's values, return its (non-negative) value.
+ * Match values of selector descriptor CA[IDX], provided IDX is not
+ * negative. CA may be null when IDX is negative.
+ * Return M_NOTFOUND if there are no matches, M_NOTUNIQUE if there are
+ * several.
+ */
+static int
+nstr_match_val(struct valstr *val, struct castr *ca, int idx)
+{
+ char id[32];
+ enum nsc_type type;
- if (str == 0) {
- *val = 0;
+ if (val->val_cat != NSC_ID || idx < 0)
+ return M_NOTFOUND;
+
+ type = nstr_promote(ca[idx].ca_type);
+ if (type == NSC_STRING)
return 0;
+
+ if (ca[idx].ca_table == EF_BAD || CANT_HAPPEN(type != NSC_LONG))
+ return M_NOTFOUND;
+
+ if (val->val_as.str.maxsz >= sizeof(id))
+ return M_NOTFOUND;
+ memcpy(id, val->val_as.str.base, val->val_as.str.maxsz);
+ id[val->val_as.str.maxsz] = 0;
+ return ef_elt_byname(ca[idx].ca_table, id);
+}
+
+/*
+ * Change VAL to resolve identifier to selector.
+ * Return VAL on success, NULL on error.
+ * No change if VAL is not an identifier.
+ * Else change VAL into symbolic value for selector CA[IDX] if IDX >=
+ * 0, and error if not.
+ */
+static struct valstr *
+nstr_resolve_id(struct valstr *val, struct castr *ca, int idx)
+{
+ if (val->val_cat != NSC_ID)
+ return val;
+
+ if (idx == M_NOTUNIQUE) {
+ pr("%.*s -- ambiguous name\n",
+ (int)val->val_as.str.maxsz, val->val_as.str.base);
+ val->val_cat = NSC_NOCAT;
+ return NULL;
}
- if (isdigit(*str) || ((*str == '-') && isdigit(str[1]))) {
- *val = atoi(str);
- return 2;
+
+ if (idx == M_NOTFOUND) {
+ pr("%.*s -- unknown name\n",
+ (int)val->val_as.str.maxsz, val->val_as.str.base);
+ val->val_cat = NSC_NOCAT;
+ return NULL;
}
- /*
- * FIXME This accepts the first match found, even if there are
- * more matches in other tables, i.e. it quietly accepts ambiguous
- * matches (matches in multiple tables), and fails to prefer an
- * exact match to partial match in an earlier table.
- */
- if ((i = typematch(str, type)) >= 0) {
- *val = i;
- return 1;
+
+ if ((ca[idx].ca_flags & NSC_DEITY) && !player->god) {
+ pr("%.*s -- not accessible to mortals\n",
+ (int)val->val_as.str.maxsz, val->val_as.str.base);
+ val->val_cat = NSC_NOCAT;
+ return NULL;
}
- if ((cap = ef_cadef(type)) != 0) {
- i = stmtch(str, (caddr_t)cap, fldoff(castr, ca_name),
- sizeof(struct castr));
- if (i >= 0) {
- *val = cap[i].ca_code | NSC_OFF;
- *val &= ~NSC_ROUND;
- return legal_val(str, *val);
- }
- if (i == M_NOTUNIQUE) {
- pr("%s -- ambiguous type selector\n", str);
- return 0;
- }
+
+ return nstr_mksymval(val, &ca[idx], 0);
+}
+
+/*
+ * Change VAL to resolve identifier to value SELVAL for selector CA.
+ * Return VAL.
+ * VAL must be an identifier, and SELVAL must have been obtained from
+ * nstr_match_val(VAL, CA0, IDX), where CA = &CA0[IDX].
+ */
+static struct valstr *
+nstr_resolve_val(struct valstr *val, int selval, struct castr *ca)
+{
+ enum nsc_type type = nstr_promote(ca->ca_type);
+
+ if (CANT_HAPPEN(val->val_cat != NSC_ID)) {
+ val->val_cat = NSC_NOCAT;
+ return val;
}
- /*
- * Only check for commodity selectors on objects which
- * are allowed to have commodities.
- */
- if (ef_flags(type) & EFF_COM) {
- i = stmtch(str, (caddr_t)var_ca, fldoff(castr, ca_name),
- sizeof(struct castr));
- if (i >= 0) {
- *val = var_ca[i].ca_code & ~NSC_ROUND;
- return legal_val(str, *val);
- }
- if (i == M_NOTUNIQUE) {
- pr("%s -- ambiguous commodity selector\n", str);
- return 0;
- }
+
+ if (type == NSC_STRING) {
+ val->val_type = NSC_STRING;
+ val->val_cat = NSC_VAL;
+ /* map identifier ~ to empty string, like some commands do */
+ if (val->val_as.str.maxsz == 1 && val->val_as.str.base[0] == '~')
+ val->val_as.str.maxsz = 0;
+ return val;
}
- pr("%s -- not a valid selector\n", str);
- return 0;
+
+ if (CANT_HAPPEN(type != NSC_LONG || ca->ca_table == EF_BAD)) {
+ val->val_type = NSC_NOTYPE;
+ val->val_cat = NSC_NOCAT;
+ return val;
+ }
+
+ val->val_type = type;
+ val->val_cat = NSC_VAL;
+ val->val_as.lng = selval;
+ return val;
}
+/*
+ * Return operator type for operand types LFT, RGT.
+ */
static int
-legal_val(s_char *str, int val)
+nstr_optype(enum nsc_type lft, enum nsc_type rgt)
{
- if (val & NSC_DEITY && !player->god) {
- pr("%s -- permission denied\n", str);
- return -1;
- }
- return 1;
+ lft = nstr_promote(lft);
+ rgt = nstr_promote(rgt);
+ if (lft == rgt)
+ return lft;
+ if (lft == NSC_DOUBLE && rgt == NSC_LONG)
+ return NSC_DOUBLE;
+ if (rgt == NSC_DOUBLE && lft == NSC_LONG)
+ return NSC_DOUBLE;
+ return NSC_NOTYPE;
}
-
/*
- * The rest of this stuff has been moved to libcommon
- * so it can be used elsewhere (emp_update, mostly)
+ * Compile a value in STR into VAL.
+ * Return a pointer to the first character after the value on success,
+ * NULL on error.
+ * TYPE is the context type, a file type.
+ * If STR names an array, VAL simply refers to the element with index
+ * zero.
*/
+char *
+nstr_comp_val(char *str, struct valstr *val, int type)
+{
+ struct castr *ca = ef_cadef(type);
+ char *tail = nstr_parse_val(str, val);
+ if (!nstr_resolve_id(val, ca, nstr_match_ca(val, ca)))
+ return NULL;
+ return tail;
+}
projects / empserver / blobdiff