usr/src/usr.bin/window/context.h

/*
 * 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.
 *
 *      @(#)context.h   3.11 (Berkeley) 6/6/90
 */

#include <stdio.h>

struct context {
        struct context *x_link;         /* nested contexts */
        char x_type;                    /* tag for union */
        union {
                struct {        /* input is a file */
                        char *X_filename;       /* input file name */
                        FILE *X_fp;             /* input stream */
                        short X_lineno;         /* current line number */
                        char X_bol;             /* at beginning of line */
                        char X_noerr;           /* don't report errors */
                        struct ww *X_errwin;    /* error window */
                } x_f;
                struct {        /* input is a buffer */
                        char *X_buf;            /* input buffer */
                        char *X_bufp;           /* current position in buf */
                        struct value *X_arg;    /* argument for alias */
                        int X_narg;             /* number of arguments */
                } x_b;
        } x_un;
                /* holding place for current token */
        int x_token;                    /* the token */
        struct value x_val;             /* values associated with token */
                /* parser error flags */
        unsigned x_erred :1;            /* had an error */
        unsigned x_synerred :1;         /* had syntax error */
        unsigned x_abort :1;            /* fatal error */
};
#define x_buf           x_un.x_b.X_buf
#define x_bufp          x_un.x_b.X_bufp
#define x_arg           x_un.x_b.X_arg
#define x_narg          x_un.x_b.X_narg
#define x_filename      x_un.x_f.X_filename
#define x_fp            x_un.x_f.X_fp
#define x_lineno        x_un.x_f.X_lineno
#define x_bol           x_un.x_f.X_bol
#define x_errwin        x_un.x_f.X_errwin
#define x_noerr         x_un.x_f.X_noerr

        /* x_type values, 0 is reserved */
#define X_FILE          1               /* input is a file */
#define X_BUF           2               /* input is a buffer */

struct context cx;                      /* the current context */