comp_scan.c

ncurses-5.4

/****************************************************************************
 * Copyright (c) 1998-2002,2003 Free Software Foundation, Inc.              *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <[e-mail]> 1992,1995               *
 *     and: Eric S. Raymond <[e-mail]>                         *
 ****************************************************************************/

/*
 *	comp_scan.c --- Lexical scanner for terminfo compiler.
 *
 *	_nc_reset_input()
 *	_nc_get_token()
 *	_nc_panic_mode()
 *	int _nc_syntax;
 *	int _nc_curr_line;
 *	long _nc_curr_file_pos;
 *	long _nc_comment_start;
 *	long _nc_comment_end;
 */

#include <curses.priv.h>

#include <ctype.h>
#include <term_entry.h>
#include <tic.h>

MODULE_ID("$Id: comp_scan.c,v 1.66 2003/12/14 00:32:40 tom Exp $")

/*
 * Maximum length of string capability we'll accept before raising an error.
 * Yes, there is a real capability in /etc/termcap this long, an "is".
 */
#define MAXCAPLEN	600

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

NCURSES_EXPORT_VAR(int)
_nc_syntax = 0;			/* termcap or terminfo? */
NCURSES_EXPORT_VAR(long)
_nc_curr_file_pos = 0;		/* file offset of current line */
NCURSES_EXPORT_VAR(long)
_nc_comment_start = 0;		/* start of comment range before name */
NCURSES_EXPORT_VAR(long)
_nc_comment_end = 0;		/* end of comment range before name */
NCURSES_EXPORT_VAR(long)
_nc_start_line = 0;		/* start line of current entry */

NCURSES_EXPORT_VAR(struct token)
_nc_curr_token =
{
    0, 0, 0
};

/*****************************************************************************
 *
 * Token-grabbing machinery
 *
 *****************************************************************************/

static bool first_column;	/* See 'next_char()' below */
static bool had_newline;
static char separator;		/* capability separator */
static int pushtype;		/* type of pushback token */
static char *pushname;

#if NCURSES_EXT_FUNCS
NCURSES_EXPORT_VAR(bool)
_nc_disable_period = FALSE;	/* used by tic -a option */
#endif

static bool end_of_stream(void);
static int last_char(void);
static int next_char(void);
static long stream_pos(void);
static void push_back(char c);

/* Assume we may be looking at a termcap-style continuation */
static inline int
eat_escaped_newline(int ch)
{
    if (ch == '\\')
	while ((ch = next_char()) == '\n' || iswhite(ch))
	    continue;
    return ch;
}

/*
 *	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 separator on the line.
 *		BOOLEAN		An entry consisting of a name followed by
 *				a separator.  '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.
 *
 *	A `separator' is either a comma or a semicolon, depending on whether
 *	we are in termcap or terminfo mode.
 *
 */

NCURSES_EXPORT(int)
_nc_get_token(bool silent)
{
    static const char terminfo_punct[] = "@%&*!#";
    static char *buffer;

    char *after_list;
    char *after_name;
    char *numchk;
    char *ptr;
    char *s;
    char numbuf[80];
    int ch;
    int dot_flag = FALSE;
    int type;
    long number;
    long token_start;
    unsigned found;

    if (pushtype != NO_PUSHBACK) {
	int retval = pushtype;

	_nc_set_type(pushname != 0 ? pushname : "");
	DEBUG(3, ("pushed-back token: `%s', class %d",
		  _nc_curr_token.tk_name, pushtype));

	pushtype = NO_PUSHBACK;
	if (pushname != 0)
	    pushname[0] = '\0';

	/* currtok wasn't altered by _nc_push_token() */
	return (retval);
    }

    if (end_of_stream()) {
	if (buffer != 0) {
	    FreeAndNull(buffer);
	}
	return (EOF);
    }

  start_token:
    token_start = stream_pos();
    while ((ch = next_char()) == '\n' || iswhite(ch)) {
	if (ch == '\n')
	    had_newline = TRUE;
	continue;
    }

    ch = eat_escaped_newline(ch);

    if (ch == EOF)
	type = EOF;
    else {
	/* if this is a termcap entry, skip a leading separator */
	if (separator == ':' && ch == ':')
	    ch = next_char();

	if (ch == '.'
#if NCURSES_EXT_FUNCS
	    && !_nc_disable_period
#endif
	    ) {
	    dot_flag = TRUE;
	    DEBUG(8, ("dot-flag set"));

	    while ((ch = next_char()) == '.' || iswhite(ch))
		continue;
	}

	if (ch == EOF) {
	    type = EOF;
	    goto end_of_token;
	}

	/* have to make some punctuation chars legal for terminfo */
	if (!isalnum(ch)
#if NCURSES_EXT_FUNCS
	    && !(ch == '.' && _nc_disable_period)
#endif
	    && !strchr(terminfo_punct, (char) ch)) {
	    if (!silent)
		_nc_warning("Illegal character (expected alphanumeric or %s) - %s",
			    terminfo_punct, unctrl((chtype) ch));
	    _nc_panic_mode(separator);
	    goto start_token;
	}

	if (buffer == 0)
	    buffer = typeMalloc(char, MAX_ENTRY_SIZE);

	ptr = buffer;
	*(ptr++) = ch;

	if (first_column) {
	    _nc_comment_start = token_start;
	    _nc_comment_end = _nc_curr_file_pos;
	    _nc_start_line = _nc_curr_line;

	    _nc_syntax = ERR;
	    after_name = 0;
	    after_list = 0;
	    while ((ch = next_char()) != '\n') {
		if (ch == EOF) {
		    _nc_err_abort(MSG_NO_MEMORY);
		} else if (ch == '|') {
		    after_list = ptr;
		    if (after_name == 0)
			after_name = ptr;
		} else if (ch == ':' && last_char() != ',') {
		    _nc_syntax = SYN_TERMCAP;
		    separator = ':';
		    break;
		} else if (ch == ',') {
		    _nc_syntax = SYN_TERMINFO;
		    separator = ',';
		    /*
		     * If we did not see a '|', then we found a name with no
		     * aliases or description.
		     */
		    if (after_name == 0)
			break;
		    /*
		     * If we see a comma, we assume this is terminfo unless we
		     * subsequently run into a colon.  But we don't stop
		     * looking for a colon until hitting a newline.  This
		     * allows commas to be embedded in description fields of
		     * either syntax.
		     */
		} else
		    ch = eat_escaped_newline(ch);

		*ptr++ = ch;
	    }
	    ptr[0] = '\0';
	    if (_nc_syntax == ERR) {
		/*
		 * Grrr...what we ought to do here is barf, complaining that
		 * the entry is malformed.  But because a couple of name fields
		 * in the 8.2 termcap file end with |\, we just have to assume
		 * it's termcap syntax.
		 */
		_nc_syntax = SYN_TERMCAP;
		separator = ':';
	    } else if (_nc_syntax == SYN_TERMINFO) {
		/* throw away trailing /, *$/ */
		for (--ptr; iswhite(*ptr) || *ptr == ','; ptr--)
		    continue;
		ptr[1] = '\0';
	    }

	    /*
	     * This is the soonest we have the terminal name fetched.  Set up
	     * for following warning messages.  If there's no '|', then there
	     * is no description.
	     */
	    if (after_name != 0) {
		ch = *after_name;
		*after_name = '\0';
		_nc_set_type(buffer);
		*after_name = ch;
	    }

	    /*
	     * Compute the boundary between the aliases and the description
	     * field for syntax-checking purposes.
	     */
	    if (after_list != 0) {
		if (!silent) {
		    if (*after_list == '\0')
			_nc_warning("empty longname field");
		    else if (strchr(after_list, ' ') == 0)
			_nc_warning("older tic versions may treat the description field as an alias");
		}
	    } else {
		after_list = buffer + strlen(buffer);
		DEBUG(1, ("missing description"));
	    }

	    /*
	     * Whitespace in a name field other than the long name can confuse
	     * rdist and some termcap tools.  Slashes are a no-no.  Other
	     * special characters can be dangerous due to shell expansion.
	     */
	    for (s = buffer; s < after_list; ++s) {
		if (isspace(UChar(*s))) {
		    if (!silent)
			_nc_warning("whitespace in name or alias field");
		    break;
		} else if (*s == '/') {
		    if (!silent)
			_nc_warning("slashes aren't allowed in names or aliases");
		    break;
		} else if (strchr("$[]!*?", *s)) {
		    if (!silent)
			_nc_warning("dubious character `%c' in name or alias field", *s);
		    break;
		}
	    }

	    _nc_curr_token.tk_name = buffer;
	    type = NAMES;
	} else {
	    if (had_newline && _nc_syntax == SYN_TERMCAP) {
		_nc_warning("Missing backslash before newline");
		had_newline = FALSE;
	    }
	    while ((ch = next_char()) != EOF) {
		if (!isalnum(ch)) {
		    if (_nc_syntax == SYN_TERMINFO) {
			if (ch != '_')
			    break;
		    } else {	/* allow ';' for "k;" */
			if (ch != ';')
			    break;
		    }
		}
		*(ptr++) = ch;
	    }

	    *ptr++ = '\0';
	    switch (ch) {
	    case ',':
	    case ':':
		if (ch != separator)
		    _nc_err_abort("Separator inconsistent with syntax");
		_nc_curr_token.tk_name = buffer;
		type = BOOLEAN;
		break;
	    case '@':
		if ((ch = next_char()) != separator && !silent)
		    _nc_warning("Missing separator after `%s', have %s",
				buffer, unctrl((chtype) ch));
		_nc_curr_token.tk_name = buffer;
		type = CANCEL;
		break;

	    case '#':
		found = 0;
		while (isalnum(ch = next_char())) {
		    numbuf[found++] = ch;
		    if (found >= sizeof(numbuf) - 1)
			break;
		}
		numbuf[found] = '\0';
		number = strtol(numbuf, &numchk, 0);
		if (!silent) {
		    if (numchk == numbuf)
			_nc_warning("no value given for `%s'", buffer);
		    if ((*numchk != '\0') || (ch != separator))
			_nc_warning("Missing separator");
		}
		_nc_curr_token.tk_name = buffer;
		_nc_curr_token.tk_valnumber = number;
		type = NUMBER;
		break;

	    case '=':
		ch = _nc_trans_string(ptr, buffer + MAX_ENTRY_SIZE);
		if (!silent && ch != separator)
		    _nc_warning("Missing separator");
		_nc_curr_token.tk_name = buffer;
		_nc_curr_token.tk_valstring = ptr;
		type = STRING;
		break;

	    case EOF:
		type = EOF;
		break;
	    default:
		/* just to get rid of the compiler warning */
		type = UNDEF;
		if (!silent)
		    _nc_warning("Illegal character - %s", unctrl((chtype) ch));
	    }
	}			/* end else (first_column == FALSE) */
    }				/* end else (ch != EOF) */

  end_of_token:

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

    if (_nc_tracing >= DEBUG_LEVEL(7)) {