BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / window / parser1.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Edward Wang at The University of California, Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
static char sccsid[] = "@(#)parser1.c   3.22 (Berkeley) 6/6/90";
#endif /* not lint */

#include "parser.h"

p_start()
{
       char flag = 1;

       (void) s_gettok();
       for (;;) {
               p_statementlist(flag);
               if (token == T_EOF || p_abort())
                       break;
               flag = 0;
               p_synerror();
               while (token != T_EOL && token != T_EOF) {
                       if (token == T_STR)
                               str_free(token_str);
                       (void) s_gettok();
               }
               if (token == T_EOL)
                       (void) s_gettok();
               p_clearerr();
       }
}

p_statementlist(flag)
char flag;
{
       for (; p_statement(flag) >= 0; p_clearerr())
               ;
}

p_statement(flag)
char flag;
{
       switch (token) {
       case T_EOL:
               (void) s_gettok();
               return 0;
       case T_IF:
               return p_if(flag);
       default:
               return p_expression(flag);
       }
}

p_if(flag)
char flag;
{
       struct value t;
       char true = 0;

top:
       (void) s_gettok();

       if (p_expr(&t, flag) < 0) {
               p_synerror();
               return -1;
       }
       switch (t.v_type) {
       case V_NUM:
               true = !true && t.v_num != 0;
               break;
       case V_STR:
               p_error("if: Numeric value required.");
               str_free(t.v_str);
       case V_ERR:
               flag = 0;
               break;
       }

       if (token != T_THEN) {
               p_synerror();
               return -1;
       }

       (void) s_gettok();
       p_statementlist(flag && true);
       if (p_erred())
               return -1;

       if (token == T_ELSIF)
               goto top;

       if (token == T_ELSE) {
               (void) s_gettok();
               p_statementlist(flag && !true);
               if (p_erred())
                       return -1;
       }

       if (token == T_ENDIF) {
               (void) s_gettok();
               return 0;
       }

       p_synerror();
       return -1;
}

p_expression(flag)
char flag;
{
       struct value t;
       char *cmd;
       int p_function(), p_assign();

       switch (token) {
       case T_NUM:
               t.v_type = V_NUM;
               t.v_num = token_num;
               (void) s_gettok();
               break;
       case T_STR:
               t.v_type = V_STR;
               t.v_str = token_str;
               (void) s_gettok();
               break;
       default:
               if (p_expr(&t, flag) < 0)
                       return -1;
               if (token == T_EOF) {
                       val_free(t);
                       return 0;
               }
       }
       if (token != T_ASSIGN && p_convstr(&t) < 0)
               return -1;
       cmd = t.v_type == V_STR ? t.v_str : 0;
       if ((*(token == T_ASSIGN ? p_assign : p_function))(cmd, &t, flag) < 0) {
               if (cmd)
                       str_free(cmd);
               return -1;
       }
       if (cmd)
               str_free(cmd);
       val_free(t);
       if (token == T_EOL)
               (void) s_gettok();
       else if (token != T_EOF) {
               p_synerror();
               return -1;
       }
       return 0;
}

p_convstr(v)
register struct value *v;
{
       if (v->v_type != V_NUM)
               return 0;
       if ((v->v_str = str_itoa(v->v_num)) == 0) {
               p_memerror();
               v->v_type = V_ERR;
               return -1;
       }
       v->v_type = V_STR;
       return 0;
}

p_synerror()
{
       if (!cx.x_synerred) {
               cx.x_synerred = cx.x_erred = 1;
               error("Syntax error.");
       }
}

/*VARARGS1*/
p_error(msg, a, b, c)
char *msg;
{
       if (!cx.x_erred) {
               cx.x_erred = 1;
               error(msg, a, b, c);
       }
}

p_memerror()
{
       cx.x_erred = cx.x_abort = 1;
       error("Out of memory.");
}