window/parser3.c

   1 /*      $NetBSD: parser3.c,v 1.4 1997/11/21 08:36:14 lukem Exp $        */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Edward Wang at The University of California, Berkeley.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. All advertising materials mentioning features or use of this software
  19  *    must display the following acknowledgement:
  20  *      This product includes software developed by the University of
  21  *      California, Berkeley and its contributors.
  22  * 4. Neither the name of the University nor the names of its contributors
  23  *    may be used to endorse or promote products derived from this software
  24  *    without specific prior written permission.
  25  *
  26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  36  * SUCH DAMAGE.
  37  */
  38
  39 #include <sys/cdefs.h>
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)parser3.c   8.1 (Berkeley) 6/6/93";
  43 #else
  44 __RCSID("$NetBSD: parser3.c,v 1.4 1997/11/21 08:36:14 lukem Exp $");
  45 #endif
  46 #endif /* not lint */
  47
  48 #include "defs.h"
  49 #include "parser.h"
  50
  51 /*
  52  * =
  53  * ? :
  54  * ||
  55  * &&
  56  * |
  57  * ^
  58  * &
  59  * == !=
  60  * <= >=
  61  * << >>
  62  * + -
  63  * * / %
  64  * unary - + ~ !
  65  */
  66 int
  67 p_expr(v, flag)
  68         struct value *v;
  69         char flag;
  70 {
  71         struct value t;
  72         int ret;
  73
  74         if (p_expr0(&t, flag) < 0)
  75                 return -1;
  76
  77         if (token != T_ASSIGN) {
  78                 *v = t;
  79                 return 0;
  80         }
  81         switch (t.v_type) {
  82         case V_NUM:
  83                 p_error("%d: Not a variable.", t.v_num);
  84         case V_ERR:
  85                 t.v_str = 0;
  86                 break;
  87         }
  88         ret = p_assign(t.v_str, v, flag);
  89         if (t.v_str != 0)
  90                 str_free(t.v_str);
  91         return ret;
  92 }
  93
  94 /*
  95  * ? :
  96  */
  97 int
  98 p_expr0(v, flag)
  99         struct value *v;
 100         char flag;
 101 {
 102         struct value t;
 103         char true = 0;
 104
 105         if (p_expr1(v, flag) < 0)
 106                 return -1;
 107         if (token != T_QUEST)
 108                 return 0;
 109         switch (v->v_type) {
 110         case V_NUM:
 111                 true = v->v_num != 0;
 112                 break;
 113         case V_STR:
 114                 p_error("?: Numeric left operand required.");
 115                 str_free(v->v_str);
 116                 v->v_type = V_ERR;
 117         case V_ERR:
 118                 flag = 0;
 119                 break;
 120         }
 121         (void) s_gettok();
 122         v->v_type = V_ERR;
 123         if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
 124                 return -1;
 125         if (token != T_COLON) {
 126                 val_free(*v);
 127                 p_synerror();
 128                 return -1;
 129         }
 130         (void) s_gettok();
 131         return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
 132 }
 133
 134 /*
 135  * ||
 136  */
 137 int
 138 p_expr1(v, flag)
 139         struct value *v;
 140         char flag;
 141 {
 142         char true = 0;
 143
 144         if (p_expr2(v, flag) < 0)
 145                 return -1;
 146         if (token != T_OROR)
 147                 return 0;
 148         for (;;) {
 149                 switch (v->v_type) {
 150                 case V_NUM:
 151                         v->v_num = true = true || v->v_num != 0;
 152                         break;
 153                 case V_STR:
 154                         p_error("||: Numeric operands required.");
 155                         str_free(v->v_str);
 156                         v->v_type = V_ERR;
 157                 case V_ERR:
 158                         flag = 0;
 159                         break;
 160                 }
 161                 if (token != T_OROR)
 162                         return 0;
 163                 (void) s_gettok();
 164                 if (p_expr2(v, flag && !true) < 0)
 165                         return -1;
 166         }
 167 }
 168
 169 /*
 170  * &&
 171  */
 172 int
 173 p_expr2(v, flag)
 174         struct value *v;
 175         char flag;
 176 {
 177         char true = 1;
 178
 179         if (p_expr3_10(3, v, flag) < 0)
 180                 return -1;
 181         if (token != T_ANDAND)
 182                 return 0;
 183         for (;;) {
 184                 switch (v->v_type) {
 185                 case V_NUM:
 186                         v->v_num = true = true && v->v_num != 0;
 187                         break;
 188                 case V_STR:
 189                         p_error("&&: Numeric operands required.");
 190                         str_free(v->v_str);
 191                         v->v_type = V_ERR;
 192                 case V_ERR:
 193                         flag = 0;
 194                         break;
 195                 }
 196                 if (token != T_ANDAND)
 197                         return 0;
 198                 (void) s_gettok();
 199                 if (p_expr3_10(3, v, flag && true) < 0)
 200                         return -1;
 201         }
 202         /*NOTREACHED*/
 203 }