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                 /* FALLTHROUGH */
  71         case V_ERR:
  72                 t.v_str = 0;
  73                 break;
  74         }
  75         ret = p_assign(t.v_str, v, flag);
  76         if (t.v_str != 0)
  77                 str_free(t.v_str);
  78         return ret;
  79 }
  80
  81 /*
  82  * ? :
  83  */
  84 int
  85 p_expr0(struct value *v, char flag)
  86 {
  87         struct value t;
  88         char true = 0;
  89
  90         if (p_expr1(v, flag) < 0)
  91                 return -1;
  92         if (token != T_QUEST)
  93                 return 0;
  94         switch (v->v_type) {
  95         case V_NUM:
  96                 true = v->v_num != 0;
  97                 break;
  98         case V_STR:
  99                 p_error("?: Numeric left operand required.");
 100                 str_free(v->v_str);
 101                 v->v_type = V_ERR;
 102                 /* FALLTHROUGH */
 103         case V_ERR:
 104                 flag = 0;
 105                 break;
 106         }
 107         (void) s_gettok();
 108         v->v_type = V_ERR;
 109         if ((flag && true ? p_expr1(v, 1) : p_expr1(&t, 0)) < 0)
 110                 return -1;
 111         if (token != T_COLON) {
 112                 val_free(*v);
 113                 p_synerror();
 114                 return -1;
 115         }
 116         (void) s_gettok();
 117         return flag && !true ? p_expr1(v, 1) : p_expr1(&t, 0);
 118 }
 119
 120 /*
 121  * ||
 122  */
 123 int
 124 p_expr1(struct value *v, char flag)
 125 {
 126         char true = 0;
 127
 128         if (p_expr2(v, flag) < 0)
 129                 return -1;
 130         if (token != T_OROR)
 131                 return 0;
 132         for (;;) {
 133                 switch (v->v_type) {
 134                 case V_NUM:
 135                         v->v_num = true = true || v->v_num != 0;
 136                         break;
 137                 case V_STR:
 138                         p_error("||: Numeric operands required.");
 139                         str_free(v->v_str);
 140                         v->v_type = V_ERR;
 141                         /* FALLTHROUGH */
 142                 case V_ERR:
 143                         flag = 0;
 144                         break;
 145                 }
 146                 if (token != T_OROR)
 147                         return 0;
 148                 (void) s_gettok();
 149                 if (p_expr2(v, flag && !true) < 0)
 150                         return -1;
 151         }
 152 }
 153
 154 /*
 155  * &&
 156  */
 157 int
 158 p_expr2(struct value *v, char flag)
 159 {
 160         char true = 1;
 161
 162         if (p_expr3_10(3, v, flag) < 0)
 163                 return -1;
 164         if (token != T_ANDAND)
 165                 return 0;
 166         for (;;) {
 167                 switch (v->v_type) {
 168                 case V_NUM:
 169                         v->v_num = true = true && v->v_num != 0;
 170                         break;
 171                 case V_STR:
 172                         p_error("&&: Numeric operands required.");
 173                         str_free(v->v_str);
 174                         v->v_type = V_ERR;
 175                         /* FALLTHROUGH */
 176                 case V_ERR:
 177                         flag = 0;
 178                         break;
 179                 }
 180                 if (token != T_ANDAND)
 181                         return 0;
 182                 (void) s_gettok();
 183                 if (p_expr3_10(3, v, flag && true) < 0)
 184                         return -1;
 185         }
 186         /*NOTREACHED*/
 187 }