usr.bin/window/parser1.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  * @(#)parser1.c        8.1 (Berkeley) 6/6/93
  37  * $FreeBSD: src/usr.bin/window/parser1.c,v 1.1.1.1.14.1 2001/05/17 09:45:00 obrien Exp $
  38  * $DragonFly: src/usr.bin/window/parser1.c,v 1.2 2003/06/17 04:29:34 dillon Exp $
  39  */
  40
  41 #include "parser.h"
  42
  43 p_start()
  44 {
  45         char flag = 1;
  46
  47         (void) s_gettok();
  48         for (;;) {
  49                 p_statementlist(flag);
  50                 if (token == T_EOF || p_abort())
  51                         break;
  52                 flag = 0;
  53                 p_synerror();
  54                 while (token != T_EOL && token != T_EOF) {
  55                         if (token == T_STR)
  56                                 str_free(token_str);
  57                         (void) s_gettok();
  58                 }
  59                 if (token == T_EOL)
  60                         (void) s_gettok();
  61                 p_clearerr();
  62         }
  63 }
  64
  65 p_statementlist(flag)
  66 char flag;
  67 {
  68         for (; p_statement(flag) >= 0; p_clearerr())
  69                 ;
  70 }
  71
  72 p_statement(flag)
  73 char flag;
  74 {
  75         switch (token) {
  76         case T_EOL:
  77                 (void) s_gettok();
  78                 return 0;
  79         case T_IF:
  80                 return p_if(flag);
  81         default:
  82                 return p_expression(flag);
  83         }
  84 }
  85
  86 p_if(flag)
  87 char flag;
  88 {
  89         struct value t;
  90         char true = 0;
  91
  92 top:
  93         (void) s_gettok();
  94
  95         if (p_expr(&t, flag) < 0) {
  96                 p_synerror();
  97                 return -1;
  98         }
  99         switch (t.v_type) {
 100         case V_NUM:
 101                 true = !true && t.v_num != 0;
 102                 break;
 103         case V_STR:
 104                 p_error("if: Numeric value required.");
 105                 str_free(t.v_str);
 106         case V_ERR:
 107                 flag = 0;
 108                 break;
 109         }
 110
 111         if (token != T_THEN) {
 112                 p_synerror();
 113                 return -1;
 114         }
 115
 116         (void) s_gettok();
 117         p_statementlist(flag && true);
 118         if (p_erred())
 119                 return -1;
 120
 121         if (token == T_ELSIF)
 122                 goto top;
 123
 124         if (token == T_ELSE) {
 125                 (void) s_gettok();
 126                 p_statementlist(flag && !true);
 127                 if (p_erred())
 128                         return -1;
 129         }
 130
 131         if (token == T_ENDIF) {
 132                 (void) s_gettok();
 133                 return 0;
 134         }
 135
 136         p_synerror();
 137         return -1;
 138 }
 139
 140 p_expression(flag)
 141 char flag;
 142 {
 143         struct value t;
 144         char *cmd;
 145         int p_function(), p_assign();
 146
 147         switch (token) {
 148         case T_NUM:
 149                 t.v_type = V_NUM;
 150                 t.v_num = token_num;
 151                 (void) s_gettok();
 152                 break;
 153         case T_STR:
 154                 t.v_type = V_STR;
 155                 t.v_str = token_str;
 156                 (void) s_gettok();
 157                 break;
 158         default:
 159                 if (p_expr(&t, flag) < 0)
 160                         return -1;
 161                 if (token == T_EOF) {
 162                         val_free(t);
 163                         return 0;
 164                 }
 165         }
 166         if (token != T_ASSIGN && p_convstr(&t) < 0)
 167                 return -1;
 168         cmd = t.v_type == V_STR ? t.v_str : 0;
 169         if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
 170                 if (cmd)
 171                         str_free(cmd);
 172                 return -1;
 173         }
 174         if (cmd)
 175                 str_free(cmd);
 176         val_free(t);
 177         if (token == T_EOL)
 178                 (void) s_gettok();
 179         else if (token != T_EOF) {
 180                 p_synerror();
 181                 return -1;
 182         }
 183         return 0;
 184 }
 185
 186 p_convstr(v)
 187 register struct value *v;
 188 {
 189         if (v->v_type != V_NUM)
 190                 return 0;
 191         if ((v->v_str = str_itoa(v->v_num)) == 0) {
 192                 p_memerror();
 193                 v->v_type = V_ERR;
 194                 return -1;
 195         }
 196         v->v_type = V_STR;
 197         return 0;
 198 }
 199
 200 p_synerror()
 201 {
 202         if (!cx.x_synerred) {
 203                 cx.x_synerred = cx.x_erred = 1;
 204                 error("Syntax error.");
 205         }
 206 }
 207
 208 /*VARARGS1*/
 209 p_error(msg, a, b, c)
 210 char *msg;
 211 {
 212         if (!cx.x_erred) {
 213                 cx.x_erred = 1;
 214                 error(msg, a, b, c);
 215         }
 216 }
 217
 218 p_memerror()
 219 {
 220         cx.x_erred = cx.x_abort = 1;
 221         error("Out of memory.");
 222 }