/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */
/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */


/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 *                      COPYRIGHT NOTICE
 *
 *      This software is copyright(C) 1982 by Pavel Curtis
 *
 *      Permission is granted to reproduce and distribute
 *      this file by any means so long as no fee is charged
 *      above a nominal handling fee and so long as this
 *      notice is always included in the copies.
 *
 *      Other rights are reserved except as explicitly granted
 *      by written permission of the author.
 *              Pavel Curtis
 *              Computer Science Dept.
 *              405 Upson Hall
 *              Cornell University
 *              Ithaca, NY 14853
 *
 *              Ph- (607) 256-4934
 *
 *              Pavel.Cornell@Udel-Relay(ARPAnet)
 *              decvax!cornell!pavel(UUCPnet)
 */

/*
 *      comp_scan.c --- Lexical scanner for terminfo compiler.
 *
 *   $Log:      RCS/comp_scan.v $
 * Revision 2.1  82/10/25  14:45:55  pavel
 * Added Copyright Notice
 *
 * Revision 2.0  82/10/24  15:17:12  pavel
 * Beta-one Test Release
 *
 * Revision 1.3  82/08/23  22:30:03  pavel
 * The REAL Alpha-one Release Version
 *
 * Revision 1.2  82/08/19  19:10:06  pavel
 * Alpha Test Release One
 *
 * Revision 1.1  82/08/12  18:37:46  pavel
 * Initial revision
 *
 *
 */


#include <stdio.h>
#include <ctype.h>
#include "compiler.h"

#define iswhite(ch)     (ch == ' ' || ch == '\t')

extern void err_abort(char *, ...);
extern void syserr_abort(char *, ...);
extern void warning(char *, ...);

static int      first_column;           /* See 'next_char()' below */

static void backspace(void);
void reset_input(void);
void panic_mode(int);



/*
 *      int
 *      get_token()
 *
 *      Scans the input for the next token, storing the specifics in the
 *      global structure 'curr_token' and returning one of the following:
 *
 *              NAMES           A line beginning in column 1.  'name'
 *                              will be set to point to everything up to
 *                              but not including the first comma on the line.
 *              BOOLEAN         An entry consisting of a name followed by
 *                              a comma.  'name' will be set to point to the
 *                              name of the capability.
 *              NUMBER          An entry of the form
 *                                      name#digits,
 *                              'name' will be set to point to the capability
 *                              name and 'valnumber' to the number given.
 *              STRING          An entry of the form
 *                                      name=characters,
 *                              'name' is set to the capability name and
 *                              'valstring' to the string of characters, with
 *                              input translations done.
 *              CANCEL          An entry of the form
 *                                      name@,
 *                              'name' is set to the capability name and
 *                              'valnumber' to -1.
 *              EOF             The end of the file has been reached.
 *
 */
int
get_token()
{
        long            number;
        int             type = UNDEF;
        register int    ch;
        static char     buffer[1024];
        register char   *ptr;
        int             dot_flag = FALSE;

        while ((ch = next_char()) == '\n' || (isascii(ch) && iswhite(ch)));

        if (ch == EOF)
            type = EOF;
        else {
            if (ch == '.') {
                dot_flag = TRUE;

                while ((ch = next_char()) == ' ' || ch == '\t');
            }

            if (! isascii(ch) || ! isalnum(ch)) {
                warning("Illegal character - '%c'", ch);
                panic_mode(',');
            }

            ptr = buffer;
            if (ch != '\n') *(ptr++) = ch;

            if (first_column) {
                while ((ch = next_char()) != ',' && ch != '\n' && ch != EOF)
                    *(ptr++) = ch;

                if (ch == EOF)
                    err_abort("Premature EOF");
                else if (ch == '\n') {
                    warning("Newline in middle of terminal name");
                    panic_mode(',');
                }

                *ptr = '\0';
                curr_token.tk_name = buffer;
                type = NAMES;
            } else {
                ch = next_char();
                while (isascii(ch) && isalnum(ch)) {
                    *(ptr++) = ch;
                    ch = next_char();
                }

                *ptr++ = '\0';
                switch (ch) {
                    case ',':
                        curr_token.tk_name = buffer;
                        type = BOOLEAN;
                        break;

                    case '@':
                        if (next_char() != ',')
                            warning("Missing comma");
                        curr_token.tk_name = buffer;
                        type = CANCEL;
                        break;

                    case '#':
                        number = 0;
                        if ((ch = next_char()) == ',')
                                warning("Missing numeric value");
                        backspace();
                        if ((ch = next_char()) == '0') {
                            if ((ch = next_char()) == 'x' || ch == 'X') {
                                while (isascii(ch = next_char()) &&
                                    isxdigit(ch)) {
                                    number *= 16;
                                    if (isdigit(ch))
                                        number += ch - '0';
                                    else if (ch >= 'a' && ch <= 'f')
                                        number += 10 + ch - 'a';
                                    else
                                        number += 10 + ch - 'A';
                                }
                            } else {
                                backspace();
                                while ((ch = next_char()) >= '0' &&
                                    ch <= '7')
                                    number = number * 8 + ch - '0';
                                }
                            } else {
                                    backspace();
                                    while (isascii(ch = next_char()) &&
                                        isdigit(ch))
                                        number = number * 10 + ch - '0';
                            }
                        if (ch != ',')
                            warning("Missing comma");
                        curr_token.tk_name = buffer;
                        curr_token.tk_valnumber = number;
                        type = NUMBER;
                        break;

                    case '=':
                        ch = trans_string(ptr);
                        if (ch != '\0' && ch != ',')
                            warning("Missing comma");
                        if (ch == '\0')
                                warning("NULL string value");
                        curr_token.tk_name = buffer;
                        curr_token.tk_valstring = ptr;
                        type = STRING;
                        break;

                    default:
                        warning("Illegal character - '%c'", ch);
                }
            } /* end else (first_column == FALSE) */
        } /* end else (ch != EOF) */

        if (dot_flag == TRUE)
            DEBUG(8, "Commented out ", "");

        if (debug_level >= 8) {
            fprintf(stderr, "Token: ");
            switch (type) {
                case BOOLEAN:
                        fprintf(stderr, "Boolean;  name='%s'\n",
                            curr_token.tk_name);
                        break;

                case NUMBER:
                        fprintf(stderr, "Number; name = '%s', value = %d\n",
                            curr_token.tk_name, curr_token.tk_valnumber);
                        break;

                case STRING:
                        fprintf(stderr, "String; name = '%s', value = '%s'\n",
                            curr_token.tk_name, curr_token.tk_valstring);
                        break;

                case CANCEL:
                        fprintf(stderr, "Cancel; name = '%s'\n",
                            curr_token.tk_name);
                    break;

                case NAMES:
                        fprintf(stderr, "Names; value = '%s'\n",
                            curr_token.tk_name);
                        break;

                case EOF:
                        fprintf(stderr, "End of file\n");
                        break;

                default:
                        warning("Bad token type");
            }
        }

        if (dot_flag == TRUE)   /* if commented out, use the next one */
            type = get_token();

        return (type);
}



/*
 *      int
 *      next_char()
 *
 *      Returns the next character in the input stream.  Comments and leading
 *      white space are stripped.  The global state variable 'firstcolumn' is
 *      set TRUE if the character returned is from the first column of the
 *      inputline.  The global variable curr_line is incremented for each new.
 *      line. The global variable curr_file_pos is set to the file offset
 *      of the beginning of each line.
 *
 */

int     curr_column = -1;
char    line[1024];

int
next_char()
{
        char    *rtn_value;
        long    ftell();
        char    *p;

        if (curr_column < 0 || curr_column > 1023 ||
            line[curr_column] == '\0') {
            do {
                        curr_file_pos = ftell(stdin);

                        if ((rtn_value = fgets(line, 1024, stdin)) == NULL)
                                return (EOF);
                        curr_line++;
                        p = &line[0];
                        while (*p && iswhite(*p)) {
                                p++;
                        }
            } while (*p == '#');

            curr_column = 0;
            while (isascii(line[curr_column]) && iswhite(line[curr_column]))
                curr_column++;
        }

        if (curr_column == 0 && line[0] != '\n')
            first_column = TRUE;
        else
            first_column = FALSE;

        return (line[curr_column++]);
}


static void
backspace(void)
{
        curr_column--;

        if (curr_column < 0)
                syserr_abort("Backspaced off beginning of line");
}



/*
 *      reset_input()
 *
 *      Resets the input-reading routines.  Used after a seek has been done.
 *
 */

void
reset_input(void)
{
        curr_column = -1;
}



/*
 *      int
 *      trans_string(ptr)
 *
 *      Reads characters using next_char() until encountering a comma, a new
 *      entry, or end-of-file.  The returned value is the character which
 *      caused reading to stop.  The following translations are done on the
 *      input:
 *
 *              ^X  goes to  ctrl-X (i.e. X & 037)
 *              {\E,\n,\r,\b,\t,\f}  go to
 *                      {ESCAPE,newline,carriage-return,backspace,tab,formfeed}
 *              {\^,\\}  go to  {carat,backslash}
 *              \ddd (for ddd = up to three octal digits)  goes to
 *                                                      the character ddd
 *
 *              \e == \E
 *              \0 == \200
 *
 */

int
trans_string(char *ptr)
{
        register int    count = 0;
        int             number;
        register int    i;
        register int    ch;

        while ((ch = next_char()) != ',' && ch != EOF && !first_column) {
            if (ch == '^') {
                ch = next_char();
                if (ch == EOF)
                    err_abort("Premature EOF");

                if (!isascii(ch) || ! isprint(ch)) {
                    warning("Illegal ^ character - '%c'", ch);
                }

                if (ch == '@')
                    *(ptr++) = 0200;
                else
                    *(ptr++) = ch & 037;
            } else if (ch == '\\') {
                ch = next_char();
                if (ch == EOF)
                    err_abort("Premature EOF");

                if (ch >= '0' && ch <= '7') {
                    number = ch - '0';
                    for (i = 0; i < 2; i++) {
                        ch = next_char();
                        if (ch == EOF)
                            err_abort("Premature EOF");

                        if (ch < '0' || ch > '7') {
                            backspace();
                            break;
                        }

                        number = number * 8 + ch - '0';
                    }

                    if (number == 0)
                        number = 0200;
                    *(ptr++) = (char)number;
                } else {
                    switch (ch) {
                        case 'E':
                        case 'e':       *(ptr++) = '\033';      break;

                        case 'l':
                        case 'n':       *(ptr++) = '\n';        break;

                        case 'r':       *(ptr++) = '\r';        break;

                        case 'b':       *(ptr++) = '\010';      break;

                        case 's':       *(ptr++) = ' ';         break;

                        case 'f':       *(ptr++) = '\014';      break;

                        case 't':       *(ptr++) = '\t';        break;

                        case '\\':      *(ptr++) = '\\';        break;

                        case '^':       *(ptr++) = '^';         break;

                        case ',':       *(ptr++) = ',';         break;

                        case ':':       *(ptr++) = ':';         break;

                        default:
                            warning("Illegal character in \\ sequence - '%c'",
                                ch);
                            *(ptr++) = ch;
                    } /* endswitch (ch) */
                } /* endelse (ch < '0' ||  ch > '7') */
            } /* end else if (ch == '\\') */
            else {
                if (ch != '\n') *(ptr++) = ch;
            }

            count ++;

            if (count > 1000)
                warning("Very long string found.  Missing comma?");
        } /* end while */

        if (ch == EOF)
            warning("Premature EOF - missing comma?");
        /* start of new description */
        else if (first_column) {
            backspace();
            warning("Missing comma?");
            /* pretend we did get a comma */
            ch = ',';
        }

        *ptr = '\0';

        if (count == 0)
                return (0);
        return (ch);
}

/*
 * Panic mode error recovery - skip everything until a "ch" is found.
 */
void
panic_mode(int ch)
{
        int c;

        for (;;) {
                c = next_char();
                if (c == ch)
                        return;
                if (c == EOF)
                        return;
        }
}