usr.bin/window/parser3.c

   1 /*      @(#)parser3.c   8.1 (Berkeley) 6/6/93   */
   2 /*      $NetBSD: parser3.c,v 1.6 2003/08/07 11:17:28 agc Exp $  */
   3
   4 /*
   5  * Copyright (c) 1983, 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Edward Wang at The University of California, Berkeley.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "defs.h"
  37 #include "parser.h"
  38
  39 /*
  40  * =
  41  * ? :
  42  * ||
  43  * &&
  44  * |
  45  * ^
  46  * &
  47  * == !=
  48  * <= >=
  49  * << >>
  50  * + -
  51  * * / %
  52  * unary - + ~ !
  53  */
  54 int
  55 p_expr(struct value *v, char flag)
  56 {
  57         struct value t;
  58         int ret;
  59
  60         if (p_expr0(&t, flag) < 0)
  61                 return -1;
  62
  63         if (token != T_ASSIGN) {
  64                 *v = t;
  65                 return 0;
  66         }
  67         switch (t.v_type) {
  68         case V_NUM:
  69                 p_error("%d: Not a variable.", t.v_num);
  70         case V_ERR:
  71                 t.v_str = 0;
  72                 break;
  73         }
  74         ret = p_assign(t.v_str, v, flag);
  75         if (t.v_str != 0)
  76                 str_free(t.v_str);
  77         return ret;
  78 }
  79
  80 /*
  81  * ? :
  82  */
  83 int
  84 p_expr0(struct value *v, char flag)
  85 {
  86         struct value t;
  87         char true = 0;
  88
  89         if (p_expr1(v, flag) < 0)
  90                 return -1;
  91         if (token != T_QUEST)
  92                 return 0;
  93         switch (v->v_type) {
  94         case V_NUM:
  95                 true = v->v_num != 0;
  96                 break;
  97         case V_STR:
  98                 p_error("?: Numeric left operand required.");
  99                 str_free(v->v_str);
 100                 v->v_type = V_ERR;
 101         case V_ERR:
 102                 flag = 0;
 103                 break;
 104         }
 105         (void) s_gettok();
 106         v->v_type = V_ERR;
 107         if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
 108                 return -1;
 109         if (token != T_COLON) {
 110                 val_free(*v);
 111                 p_synerror();
 112                 return -1;
 113         }
 114         (void) s_gettok();
 115         return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
 116 }
 117
 118 /*
 119  * ||
 120  */
 121 int
 122 p_expr1(struct value *v, char flag)
 123 {
 124         char true = 0;
 125
 126         if (p_expr2(v, flag) < 0)
 127                 return -1;
 128         if (token != T_OROR)
 129                 return 0;
 130         for (;;) {
 131                 switch (v->v_type) {
 132                 case V_NUM:
 133                         v->v_num = true = true || v->v_num != 0;
 134                         break;
 135                 case V_STR:
 136                         p_error("||: Numeric operands required.");
 137                         str_free(v->v_str);
 138                         v->v_type = V_ERR;
 139                 case V_ERR:
 140                         flag = 0;
 141                         break;
 142                 }
 143                 if (token != T_OROR)
 144                         return 0;
 145                 (void) s_gettok();
 146                 if (p_expr2(v, flag && !true) < 0)
 147                         return -1;
 148         }
 149 }
 150
 151 /*
 152  * &&
 153  */
 154 int
 155 p_expr2(struct value *v, char flag)
 156 {
 157         char true = 1;
 158
 159         if (p_expr3_10(3, v, flag) < 0)
 160                 return -1;
 161         if (token != T_ANDAND)
 162                 return 0;
 163         for (;;) {
 164                 switch (v->v_type) {
 165                 case V_NUM:
 166                         v->v_num = true = true && v->v_num != 0;
 167                         break;
 168                 case V_STR:
 169                         p_error("&&: Numeric operands required.");
 170                         str_free(v->v_str);
 171                         v->v_type = V_ERR;
 172                 case V_ERR:
 173                         flag = 0;
 174                         break;
 175                 }
 176                 if (token != T_ANDAND)
 177                         return 0;
 178                 (void) s_gettok();
 179                 if (p_expr3_10(3, v, flag && true) < 0)
 180                         return -1;
 181         }
 182         /*NOTREACHED*/
 183 }