usr.bin/window/parser3.c

   1 /*      $NetBSD: parser3.c,v 1.5 2002/06/14 01:06:54 wiz 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. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include <sys/cdefs.h>
  36 #ifndef lint
  37 #if 0
  38 static char sccsid[] = "@(#)parser3.c   8.1 (Berkeley) 6/6/93";
  39 #else
  40 __RCSID("$NetBSD: parser3.c,v 1.5 2002/06/14 01:06:54 wiz Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include "defs.h"
  45 #include "parser.h"
  46
  47 /*
  48  * =
  49  * ? :
  50  * ||
  51  * &&
  52  * |
  53  * ^
  54  * &
  55  * == !=
  56  * <= >=
  57  * << >>
  58  * + -
  59  * * / %
  60  * unary - + ~ !
  61  */
  62 int
  63 p_expr(struct value *v, char flag)
  64 {
  65         struct value t;
  66         int ret;
  67
  68         if (p_expr0(&t, flag) < 0)
  69                 return -1;
  70
  71         if (token != T_ASSIGN) {
  72                 *v = t;
  73                 return 0;
  74         }
  75         switch (t.v_type) {
  76         case V_NUM:
  77                 p_error("%d: Not a variable.", t.v_num);
  78         case V_ERR:
  79                 t.v_str = 0;
  80                 break;
  81         }
  82         ret = p_assign(t.v_str, v, flag);
  83         if (t.v_str != 0)
  84                 str_free(t.v_str);
  85         return ret;
  86 }
  87
  88 /*
  89  * ? :
  90  */
  91 int
  92 p_expr0(struct value *v, char flag)
  93 {
  94         struct value t;
  95         char true = 0;
  96
  97         if (p_expr1(v, flag) < 0)
  98                 return -1;
  99         if (token != T_QUEST)
 100                 return 0;
 101         switch (v->v_type) {
 102         case V_NUM:
 103                 true = v->v_num != 0;
 104                 break;
 105         case V_STR:
 106                 p_error("?: Numeric left operand required.");
 107                 str_free(v->v_str);
 108                 v->v_type = V_ERR;
 109         case V_ERR:
 110                 flag = 0;
 111                 break;
 112         }
 113         (void) s_gettok();
 114         v->v_type = V_ERR;
 115         if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
 116                 return -1;
 117         if (token != T_COLON) {
 118                 val_free(*v);
 119                 p_synerror();
 120                 return -1;
 121         }
 122         (void) s_gettok();
 123         return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
 124 }
 125
 126 /*
 127  * ||
 128  */
 129 int
 130 p_expr1(struct value *v, char flag)
 131 {
 132         char true = 0;
 133
 134         if (p_expr2(v, flag) < 0)
 135                 return -1;
 136         if (token != T_OROR)
 137                 return 0;
 138         for (;;) {
 139                 switch (v->v_type) {
 140                 case V_NUM:
 141                         v->v_num = true = true || v->v_num != 0;
 142                         break;
 143                 case V_STR:
 144                         p_error("||: Numeric operands required.");
 145                         str_free(v->v_str);
 146                         v->v_type = V_ERR;
 147                 case V_ERR:
 148                         flag = 0;
 149                         break;
 150                 }
 151                 if (token != T_OROR)
 152                         return 0;
 153                 (void) s_gettok();
 154                 if (p_expr2(v, flag && !true) < 0)
 155                         return -1;
 156         }
 157 }
 158
 159 /*
 160  * &&
 161  */
 162 int
 163 p_expr2(struct value *v, char flag)
 164 {
 165         char true = 1;
 166
 167         if (p_expr3_10(3, v, flag) < 0)
 168                 return -1;
 169         if (token != T_ANDAND)
 170                 return 0;
 171         for (;;) {
 172                 switch (v->v_type) {
 173                 case V_NUM:
 174                         v->v_num = true = true && v->v_num != 0;
 175                         break;
 176                 case V_STR:
 177                         p_error("&&: Numeric operands required.");
 178                         str_free(v->v_str);
 179                         v->v_type = V_ERR;
 180                 case V_ERR:
 181                         flag = 0;
 182                         break;
 183                 }
 184                 if (token != T_ANDAND)
 185                         return 0;
 186                 (void) s_gettok();
 187                 if (p_expr3_10(3, v, flag && true) < 0)
 188                         return -1;
 189         }
 190         /*NOTREACHED*/
 191 }