usr.bin/window/parser3.c

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