usr.bin/window/parser1.c

   1 /*      $NetBSD: parser1.c,v 1.5 2002/06/14 01:06:53 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[] = "@(#)parser1.c   8.1 (Berkeley) 6/6/93";
  39 #else
  40 __RCSID("$NetBSD: parser1.c,v 1.5 2002/06/14 01:06:53 wiz Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include "defs.h"
  45 #include "parser.h"
  46
  47 void
  48 p_start(void)
  49 {
  50         char flag = 1;
  51
  52         (void) s_gettok();
  53         for (;;) {
  54                 p_statementlist(flag);
  55                 if (token == T_EOF || p_abort())
  56                         break;
  57                 flag = 0;
  58                 p_synerror();
  59                 while (token != T_EOL && token != T_EOF) {
  60                         if (token == T_STR)
  61                                 str_free(token_str);
  62                         (void) s_gettok();
  63                 }
  64                 if (token == T_EOL)
  65                         (void) s_gettok();
  66                 p_clearerr();
  67         }
  68 }
  69
  70 void
  71 p_statementlist(char flag)
  72 {
  73         for (; p_statement(flag) >= 0; p_clearerr())
  74                 ;
  75 }
  76
  77 int
  78 p_statement(char flag)
  79 {
  80         switch (token) {
  81         case T_EOL:
  82                 (void) s_gettok();
  83                 return 0;
  84         case T_IF:
  85                 return p_if(flag);
  86         default:
  87                 return p_expression(flag);
  88         }
  89 }
  90
  91 int
  92 p_if(char flag)
  93 {
  94         struct value t;
  95         char true = 0;
  96
  97 top:
  98         (void) s_gettok();
  99
 100         if (p_expr(&t, flag) < 0) {
 101                 p_synerror();
 102                 return -1;
 103         }
 104         switch (t.v_type) {
 105         case V_NUM:
 106                 true = !true && t.v_num != 0;
 107                 break;
 108         case V_STR:
 109                 p_error("if: Numeric value required.");
 110                 str_free(t.v_str);
 111         case V_ERR:
 112                 flag = 0;
 113                 break;
 114         }
 115
 116         if (token != T_THEN) {
 117                 p_synerror();
 118                 return -1;
 119         }
 120
 121         (void) s_gettok();
 122         p_statementlist(flag && true);
 123         if (p_erred())
 124                 return -1;
 125
 126         if (token == T_ELSIF)
 127                 goto top;
 128
 129         if (token == T_ELSE) {
 130                 (void) s_gettok();
 131                 p_statementlist(flag && !true);
 132                 if (p_erred())
 133                         return -1;
 134         }
 135
 136         if (token == T_ENDIF) {
 137                 (void) s_gettok();
 138                 return 0;
 139         }
 140
 141         p_synerror();
 142         return -1;
 143 }
 144
 145 int
 146 p_expression(char flag)
 147 {
 148         struct value t;
 149         char *cmd;
 150
 151         switch (token) {
 152         case T_NUM:
 153                 t.v_type = V_NUM;
 154                 t.v_num = token_num;
 155                 (void) s_gettok();
 156                 break;
 157         case T_STR:
 158                 t.v_type = V_STR;
 159                 t.v_str = token_str;
 160                 (void) s_gettok();
 161                 break;
 162         default:
 163                 if (p_expr(&t, flag) < 0)
 164                         return -1;
 165                 if (token == T_EOF) {
 166                         val_free(t);
 167                         return 0;
 168                 }
 169         }
 170         if (token != T_ASSIGN && p_convstr(&t) < 0)
 171                 return -1;
 172         cmd = t.v_type == V_STR ? t.v_str : 0;
 173         if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
 174                 if (cmd)
 175                         str_free(cmd);
 176                 return -1;
 177         }
 178         if (cmd)
 179                 str_free(cmd);
 180         val_free(t);
 181         if (token == T_EOL)
 182                 (void) s_gettok();
 183         else if (token != T_EOF) {
 184                 p_synerror();
 185                 return -1;
 186         }
 187         return 0;
 188 }
 189
 190 int
 191 p_convstr(struct value *v)
 192 {
 193         if (v->v_type != V_NUM)
 194                 return 0;
 195         if ((v->v_str = str_itoa(v->v_num)) == 0) {
 196                 p_memerror();
 197                 v->v_type = V_ERR;
 198                 return -1;
 199         }
 200         v->v_type = V_STR;
 201         return 0;
 202 }
 203
 204 void
 205 p_synerror(void)
 206 {
 207         if (!cx.x_synerred) {
 208                 cx.x_synerred = cx.x_erred = 1;
 209                 error("Syntax error.");
 210         }
 211 }
 212
 213 void
 214 p_error(const char *msg, ...)
 215 {
 216         va_list ap;
 217
 218         va_start(ap, msg);
 219         if (!cx.x_erred) {
 220                 cx.x_erred = 1;
 221                 verror(msg, ap);
 222         }
 223         va_end(ap);
 224 }
 225
 226 void
 227 p_memerror(void)
 228 {
 229         cx.x_erred = cx.x_abort = 1;
 230         error("Out of memory.");
 231 }