freebsd-dev/usr.bin/window/parser1.c

223 lines
4.6 KiB
C
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1994-05-27 12:33:43 +00:00
/*
* Copyright (c) 1983, 1993
* The 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 8.1 (Berkeley) 6/6/93";
#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.");
}