[apple/xnu.git] / osfmk / ddb / db_lex.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. The rights granted to you under the License
 * may not be used to create, or enable the creation or redistribution of,
 * unlawful or unlicensed copies of an Apple operating system, or to
 * circumvent, violate, or enable the circumvention or violation of, any
 * terms of an Apple operating system software license agreement.
 * 
 * Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
 */
/*
 * @OSF_COPYRIGHT@
 */
/*
 * HISTORY
 * 
 * Revision 1.1.1.1  1998/09/22 21:05:48  wsanchez
 * Import of Mac OS X kernel (~semeria)
 *
 * Revision 1.1.1.1  1998/03/07 02:26:09  wsanchez
 * Import of OSF Mach kernel (~mburg)
 *
 * Revision 1.1.11.3  1996/01/09  19:15:49  devrcs
 * 	Change 'register foo' to 'register int foo'.
 * 	[1995/12/01  21:42:12  jfraser]
 *
 * 	Merged '64-bit safe' changes from DEC alpha port.
 * 	[1995/11/21  18:03:11  jfraser]
 *
 * Revision 1.1.11.2  1995/01/06  19:10:21  devrcs
 * 	mk6 CR668 - 1.3b26 merge
 * 	* Revision 1.1.4.6  1994/05/06  18:39:20  tmt
 * 	Merged osc1.3dec/shared with osc1.3b19
 * 	Merge Alpha changes into osc1.312b source code.
 * 	String protos.
 * 	64bit cleanup.
 * 	Cleanup to quiet gcc warnings.
 * 	* End1.3merge
 * 	[1994/11/04  08:49:35  dwm]
 * 
 * Revision 1.1.11.1  1994/09/23  01:19:59  ezf
 * 	change marker to not FREE
 * 	[1994/09/22  21:10:14  ezf]
 * 
 * Revision 1.1.4.4  1993/08/11  20:37:55  elliston
 * 	Add ANSI Prototypes.  CR #9523.
 * 	[1993/08/11  03:33:26  elliston]
 * 
 * Revision 1.1.4.3  1993/07/27  18:27:38  elliston
 * 	Add ANSI prototypes.  CR #9523.
 * 	[1993/07/27  18:12:13  elliston]
 * 
 * Revision 1.1.4.2  1993/06/02  23:11:27  jeffc
 * 	Added to OSF/1 R1.3 from NMK15.0.
 * 	[1993/06/02  20:56:32  jeffc]
 * 
 * Revision 1.1  1992/09/30  02:01:10  robert
 * 	Initial revision
 * 
 * $EndLog$
 */
/* CMU_HIST */
/*
 * Revision 2.5  91/10/09  16:00:20  af
 * 	 Revision 2.4.3.1  91/10/05  13:06:25  jeffreyh
 * 	 	Added relational operator tokens and string constant etc.
 * 	 	Added input switching functions for macro and conditional command.
 * 	 	Moved skip_to_eol() from db_command.c and added db_last_lp to print
 * 	 	  skipped input data as a warning message.
 * 	 	Added last input repetition support to db_read_line.
 * 	 	Changed db_lex() to always set db_tok_string for error message.
 * 	 	[91/08/29            tak]
 * 
 * Revision 2.4.3.1  91/10/05  13:06:25  jeffreyh
 * 	Added relational operator tokens and string constant etc.
 * 	Added input switching functions for macro and conditional command.
 * 	Moved skip_to_eol() from db_command.c and added db_last_lp to print
 * 	  skipped input data as a warning message.
 * 	Added last input repetition support to db_read_line.
 * 	Changed db_lex() to always set db_tok_string for error message.
 * 	[91/08/29            tak]
 * 
 * Revision 2.4  91/05/14  15:34:23  mrt
 * 	Correcting copyright
 *
 * Revision 2.3  91/02/05  17:06:36  mrt
 * 	Changed to new Mach copyright
 * 	[91/01/31  16:18:20  mrt]
 * 
 * Revision 2.2  90/08/27  21:51:10  dbg
 * 	Add 'dotdot' token.
 * 	[90/08/22            dbg]
 * 
 * 	Allow backslash to quote any character into an identifier.
 * 	Allow colon in identifier for symbol table qualification.
 * 	[90/08/16            dbg]
 * 	Reduce lint.
 * 	[90/08/07            dbg]
 * 	Created.
 * 	[90/07/25            dbg]
 * 
 */
/* CMU_ENDHIST */
/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 */
/*
 *	Author: David B. Golub, Carnegie Mellon University
 *	Date:	7/90
 */
/*
 * Lexical analyzer.
 */
#include <string.h>			/* For strcpy(), strncmp(), strlen() */
#include <ddb/db_lex.h>
#include <ddb/db_command.h>
#include <ddb/db_input.h>
#include <ddb/db_output.h>		/* For db_printf() */

char	db_line[DB_LEX_LINE_SIZE];
char	db_last_line[DB_LEX_LINE_SIZE];
char	*db_lp, *db_endlp;
char	*db_last_lp;
int	db_look_char = 0;
db_expr_t db_look_token = 0;


/* Prototypes for functions local to this file.  XXX -- should be static!
 */
void db_flush_line(void);
void db_unread_char(int c);


int
db_read_line(char *repeat_last)
{
	int	i;

	i = db_readline(db_line, sizeof(db_line));
	if (i == 0)
	    return (0);	/* EOI */
	if (repeat_last) {
	    if (strncmp(db_line, repeat_last, strlen(repeat_last)) == 0) {
		strcpy(db_line, db_last_line);
		db_printf("%s", db_line);
		i = strlen(db_line);
	    } else if (db_line[0] != '\n' && db_line[0] != 0)
		strcpy(db_last_line, db_line);
	}
	db_lp = db_line;
	db_endlp = db_lp + i;
	db_last_lp = db_lp;
	db_look_char = 0;
	db_look_token = 0;
	return (i);
}

void
db_flush_line(void)
{
	db_lp = db_line;
	db_last_lp = db_lp;
	db_endlp = db_line;
}

void
db_switch_input(
	char	*buffer,
	int	size)
{
	db_lp = buffer;
	db_last_lp = db_lp;
	db_endlp = buffer + size;
	db_look_char = 0;
	db_look_token = 0;
}

void
db_save_lex_context(register struct db_lex_context *lp)
{
	lp->l_ptr = db_lp;
	lp->l_eptr = db_endlp;
	lp->l_char = db_look_char;
	lp->l_token = db_look_token;
}

void
db_restore_lex_context(register struct db_lex_context *lp)
{
	db_lp = lp->l_ptr;
	db_last_lp = db_lp;
	db_endlp = lp->l_eptr;
	db_look_char = lp->l_char;
	db_look_token = lp->l_token;
}

int
db_read_char(void)
{
	int	c;

	if (db_look_char != 0) {
	    c = db_look_char;
	    db_look_char = 0;
	}
	else if (db_lp >= db_endlp)
	    c = -1;
	else 
	    c = *db_lp++;
	return (c);
}

void
db_unread_char(int c)
{
	db_look_char = c;
}

void
db_unread_token(int t)
{
	db_look_token = t;
}

int
db_read_token(void)
{
	int	t;

	if (db_look_token) {
	    t = db_look_token;
	    db_look_token = 0;
	}
	else {
	    db_last_lp = db_lp;
	    if (db_look_char)
		db_last_lp--;
	    t = db_lex();
	}
	return (t);
}

db_expr_t db_tok_number;
char	db_tok_string[TOK_STRING_SIZE];

db_expr_t db_radix = 16;

void
db_flush_lex(void)
{
	db_flush_line();
	db_look_char = 0;
	db_look_token = 0;
}

#define	DB_DISP_SKIP	40		/* number of chars to display skip */

void
db_skip_to_eol(void)
{
	register int skip;
	register int t;
	register int n;
	register char *p;

	t = db_read_token();
	p = db_last_lp;
	for (skip = 0; t != tEOL && t != tSEMI_COLON && t != tEOF; skip++)
	    t = db_read_token();
	if (t == tSEMI_COLON)
	    db_unread_token(t);
	if (skip != 0) {
	    while (p < db_last_lp && (*p == ' ' || *p == '\t'))
		p++;
	    db_printf("Warning: Skipped input data \"");
	    for (n = 0; n < DB_DISP_SKIP && p < db_last_lp; n++)
		db_printf("%c", *p++);
	    if (n >= DB_DISP_SKIP)
		db_printf("....");
	    db_printf("\"\n");
	}
}

int
db_lex(void)
{
	register char *cp;
	register int c;

	c = db_read_char();
	while (c <= ' ' || c > '~') {
	    if (c == '\n' || c == -1)
		return (tEOL);
	    c = db_read_char();
	}

	cp = db_tok_string;
	*cp++ = c;

	if (c >= '0' && c <= '9') {
	    /* number */
	    int	r, digit;

	    if (c > '0')
		r = db_radix;
	    else {
		c = db_read_char();
		if (c == 'O' || c == 'o')
		    r = 8;
		else if (c == 'T' || c == 't')
		    r = 10;
		else if (c == 'X' || c == 'x')
		    r = 16;
		else {
		    cp--;
		    r = db_radix;
		    db_unread_char(c);
		}
		c = db_read_char();
		*cp++ = c;
	    }
	    db_tok_number = 0;
	    for (;;) {
		if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
		    digit = c - '0';
		else if (r == 16 && ((c >= 'A' && c <= 'F') ||
				     (c >= 'a' && c <= 'f'))) {
		    if (c >= 'a')
			digit = c - 'a' + 10;
		    else
			digit = c - 'A' + 10;
		}
		else
		    break;
		db_tok_number = db_tok_number * r + digit;
		c = db_read_char();
		if (cp < &db_tok_string[sizeof(db_tok_string)-1])
			*cp++ = c;
	    }
	    cp[-1] = 0;
	    if ((c >= '0' && c <= '9') ||
		(c >= 'A' && c <= 'Z') ||
		(c >= 'a' && c <= 'z') ||
		(c == '_'))
	    {
		db_printf("Bad character '%c' after number %s\n", 
				c, db_tok_string);
		db_error(0);
		db_flush_lex();
		return (tEOF);
	    }
	    db_unread_char(c);
	    return (tNUMBER);
	}
	if ((c >= 'A' && c <= 'Z') ||
	    (c >= 'a' && c <= 'z') ||
	    c == '_' || c == '\\' || c == ':')
	{
	    /* identifier */
	    if (c == '\\') {
		c = db_read_char();
		if (c == '\n' || c == -1)
		    db_error("Bad '\\' at the end of line\n");
	        cp[-1] = c;
	    }
	    while (1) {
		c = db_read_char();
		if ((c >= 'A' && c <= 'Z') ||
		    (c >= 'a' && c <= 'z') ||
		    (c >= '0' && c <= '9') ||
		    c == '_' || c == '\\' || c == ':' || c == '.')
		{
		    if (c == '\\') {
			c = db_read_char();
			if (c == '\n' || c == -1)
			    db_error("Bad '\\' at the end of line\n");
		    }
		    *cp++ = c;
		    if (cp == db_tok_string+sizeof(db_tok_string)) {
			db_error("String too long\n");
			db_flush_lex();
			return (tEOF);
		    }
		    continue;
		}
		else {
		    *cp = '\0';
		    break;
		}
	    }
	    db_unread_char(c);
	    return (tIDENT);
	}

	*cp = 0;
	switch (c) {
	    case '+':
		return (tPLUS);
	    case '-':
		return (tMINUS);
	    case '.':
		c = db_read_char();
		if (c == '.') {
		    *cp++ = c;
		    *cp = 0;
		    return (tDOTDOT);
		}
		db_unread_char(c);
		return (tDOT);
	    case '*':
		return (tSTAR);
	    case '/':
		return (tSLASH);
	    case '=':
		c = db_read_char();
		if (c == '=') {
		    *cp++ = c;
		    *cp = 0;
		    return(tLOG_EQ);
		}
		db_unread_char(c);
		return (tEQ);
	    case '%':
		return (tPCT);
	    case '#':
		return (tHASH);
	    case '(':
		return (tLPAREN);
	    case ')':
		return (tRPAREN);
	    case ',':
		return (tCOMMA);
	    case '\'':
		return (tQUOTE);
	    case '"':
		/* string */
		cp = db_tok_string;
		c = db_read_char();
		while (c != '"' && c > 0 && c != '\n') {
		    if (cp >= &db_tok_string[sizeof(db_tok_string)-1]) {
			db_error("Too long string\n");
			db_flush_lex();
			return (tEOF);
		    }
		    if (c == '\\') {
			c = db_read_char();
			switch(c) {
			case 'n':
			    c = '\n'; break;
			case 't':
			    c = '\t'; break;
			case '\\':
			case '"':
			    break;
			default:
			    db_printf("Bad escape sequence '\\%c'\n", c);
			    db_error(0);
			    db_flush_lex();
			    return (tEOF);
			}
		    }
		    *cp++ = c;
		    c = db_read_char();
		}
		*cp = 0;
		if (c != '"') {
		    db_error("Non terminated string constant\n");
		    db_flush_lex();
		    return (tEOF);
		}
		return (tSTRING);
	    case '$':
		return (tDOLLAR);
	    case '!':
		c = db_read_char();
		if (c == '=') {
		    *cp++ = c;
		    *cp = 0;
		    return(tLOG_NOT_EQ);
		}
		db_unread_char(c);
		return (tEXCL);
	    case '&':
		c = db_read_char();
		if (c == '&') {
		    *cp++ = c;
		    *cp = 0;
		    return(tLOG_AND);
		}
		db_unread_char(c);
		return(tBIT_AND);
	    case '|':
		c = db_read_char();
		if (c == '|') {
		    *cp++ = c;
		    *cp = 0;
		    return(tLOG_OR);
		}
		db_unread_char(c);
		return(tBIT_OR);
	    case '<':
		c = db_read_char();
		*cp++ = c;
		*cp = 0;
		if (c == '<')
		    return (tSHIFT_L);
		if (c == '=')
		    return (tLESS_EQ);
		cp[-1] = 0;
		db_unread_char(c);
		return(tLESS);
		break;
	    case '>':
		c = db_read_char();
		*cp++ = c;
		*cp = 0;
		if (c == '>')
		    return (tSHIFT_R);
		if (c == '=')
		    return (tGREATER_EQ);
		cp[-1] = 0;
		db_unread_char(c);
		return (tGREATER);
		break;
	    case ';':
		return (tSEMI_COLON);
	    case '?':
		return (tQUESTION);
	    case -1:
		strcpy(db_tok_string, "<EOL>");
		return (tEOF);
	}
	db_printf("Bad character '%c'\n", c);
	db_flush_lex();
	return (tEOF);
}
Commit	Line	Data
1c79356b A	1	/*
	2	* Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
	3	*
8f6c56a5	4	* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
1c79356b	5	*
8f6c56a5 A	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. The rights granted to you under the License
	10	* may not be used to create, or enable the creation or redistribution of,
	11	* unlawful or unlicensed copies of an Apple operating system, or to
	12	* circumvent, violate, or enable the circumvention or violation of, any
	13	* terms of an Apple operating system software license agreement.
	14	*
	15	* Please obtain a copy of the License at
	16	* http://www.opensource.apple.com/apsl/ and read it before using this file.
	17	*
	18	* The Original Code and all software distributed under the License are
	19	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	20	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	21	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	23	* Please see the License for the specific language governing rights and
8ad349bb	24	* limitations under the License.
8f6c56a5 A	25	*
8f6c56a5 A	26	* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
1c79356b A	27	*/
	28	/*
	29	* @OSF_COPYRIGHT@
	30	*/
	31	/*
	32	* HISTORY
	33	*
	34	* Revision 1.1.1.1 1998/09/22 21:05:48 wsanchez
	35	* Import of Mac OS X kernel (~semeria)
	36	*
	37	* Revision 1.1.1.1 1998/03/07 02:26:09 wsanchez
	38	* Import of OSF Mach kernel (~mburg)
	39	*
	40	* Revision 1.1.11.3 1996/01/09 19:15:49 devrcs
	41	* Change 'register foo' to 'register int foo'.
	42	* [1995/12/01 21:42:12 jfraser]
	43	*
	44	* Merged '64-bit safe' changes from DEC alpha port.
	45	* [1995/11/21 18:03:11 jfraser]
	46	*
	47	* Revision 1.1.11.2 1995/01/06 19:10:21 devrcs
	48	* mk6 CR668 - 1.3b26 merge
	49	* * Revision 1.1.4.6 1994/05/06 18:39:20 tmt
	50	* Merged osc1.3dec/shared with osc1.3b19
	51	* Merge Alpha changes into osc1.312b source code.
	52	* String protos.
	53	* 64bit cleanup.
	54	* Cleanup to quiet gcc warnings.
	55	* * End1.3merge
	56	* [1994/11/04 08:49:35 dwm]
	57	*
	58	* Revision 1.1.11.1 1994/09/23 01:19:59 ezf
	59	* change marker to not FREE
	60	* [1994/09/22 21:10:14 ezf]
	61	*
	62	* Revision 1.1.4.4 1993/08/11 20:37:55 elliston
	63	* Add ANSI Prototypes. CR #9523.
	64	* [1993/08/11 03:33:26 elliston]
	65	*
	66	* Revision 1.1.4.3 1993/07/27 18:27:38 elliston
	67	* Add ANSI prototypes. CR #9523.
	68	* [1993/07/27 18:12:13 elliston]
	69	*
	70	* Revision 1.1.4.2 1993/06/02 23:11:27 jeffc
	71	* Added to OSF/1 R1.3 from NMK15.0.
	72	* [1993/06/02 20:56:32 jeffc]
	73	*
	74	* Revision 1.1 1992/09/30 02:01:10 robert
	75	* Initial revision
	76	*
	77	* $EndLog$
	78	*/
	79	/* CMU_HIST */
	80	/*
	81	* Revision 2.5 91/10/09 16:00:20 af
	82	* Revision 2.4.3.1 91/10/05 13:06:25 jeffreyh
	83	* Added relational operator tokens and string constant etc.
	84	* Added input switching functions for macro and conditional command.
	85	* Moved skip_to_eol() from db_command.c and added db_last_lp to print
	86	* skipped input data as a warning message.
	87	* Added last input repetition support to db_read_line.
	88	* Changed db_lex() to always set db_tok_string for error message.
	89	* [91/08/29 tak]
	90	*
91	* Revision 2.4.3.1 91/10/05 13:06:25 jeffreyh
92	* Added relational operator tokens and string constant etc.
93	* Added input switching functions for macro and conditional command.
94	* Moved skip_to_eol() from db_command.c and added db_last_lp to print
95	* skipped input data as a warning message.
96	* Added last input repetition support to db_read_line.
97	* Changed db_lex() to always set db_tok_string for error message.
98	* [91/08/29 tak]
99	*
100	* Revision 2.4 91/05/14 15:34:23 mrt
101	* Correcting copyright
102	*
103	* Revision 2.3 91/02/05 17:06:36 mrt
104	* Changed to new Mach copyright
105	* [91/01/31 16:18:20 mrt]
106	*
107	* Revision 2.2 90/08/27 21:51:10 dbg
108	* Add 'dotdot' token.
109	* [90/08/22 dbg]
110	*
111	* Allow backslash to quote any character into an identifier.
112	* Allow colon in identifier for symbol table qualification.
113	* [90/08/16 dbg]
114	* Reduce lint.
115	* [90/08/07 dbg]
116	* Created.
117	* [90/07/25 dbg]
118	*
119	*/
120	/* CMU_ENDHIST */
121	/*
122	* Mach Operating System
123	* Copyright (c) 1991,1990 Carnegie Mellon University
124	* All Rights Reserved.
125	*
126	* Permission to use, copy, modify and distribute this software and its
127	* documentation is hereby granted, provided that both the copyright
128	* notice and this permission notice appear in all copies of the
129	* software, derivative works or modified versions, and any portions
130	* thereof, and that both notices appear in supporting documentation.
131	*
132	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
133	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
134	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
135	*
136	* Carnegie Mellon requests users of this software to return to
137	*
138	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
139	* School of Computer Science
140	* Carnegie Mellon University
141	* Pittsburgh PA 15213-3890
142	*
143	* any improvements or extensions that they make and grant Carnegie Mellon
144	* the rights to redistribute these changes.
145	*/
146	/*
147	*/
148	/*
149	* Author: David B. Golub, Carnegie Mellon University
150	* Date: 7/90
151	*/
152	/*
153	* Lexical analyzer.
154	*/
155	#include <string.h> /* For strcpy(), strncmp(), strlen() */
156	#include <ddb/db_lex.h>
157	#include <ddb/db_command.h>
158	#include <ddb/db_input.h>
159	#include <ddb/db_output.h> /* For db_printf() */
160
161	char db_line[DB_LEX_LINE_SIZE];
162	char db_last_line[DB_LEX_LINE_SIZE];
163	char db_lp, db_endlp;
164	char *db_last_lp;
165	int db_look_char = 0;
166	db_expr_t db_look_token = 0;
167
168
169	/* Prototypes for functions local to this file. XXX -- should be static!
170	*/
171	void db_flush_line(void);
172	void db_unread_char(int c);
173
174
175	int
176	db_read_line(char *repeat_last)
177	{
178	int i;
179
180	i = db_readline(db_line, sizeof(db_line));
181	if (i == 0)
182	return (0); /* EOI */
183	if (repeat_last) {
184	if (strncmp(db_line, repeat_last, strlen(repeat_last)) == 0) {
185	strcpy(db_line, db_last_line);
186	db_printf("%s", db_line);
187	i = strlen(db_line);
188	} else if (db_line[0] != '\n' && db_line[0] != 0)
189	strcpy(db_last_line, db_line);
190	}
191	db_lp = db_line;
192	db_endlp = db_lp + i;
193	db_last_lp = db_lp;
194	db_look_char = 0;
195	db_look_token = 0;
196	return (i);
197	}
198
199	void
200	db_flush_line(void)
201	{
202	db_lp = db_line;
203	db_last_lp = db_lp;
204	db_endlp = db_line;
205	}
206
207	void
208	db_switch_input(
209	char *buffer,
210	int size)
211	{
212	db_lp = buffer;
213	db_last_lp = db_lp;
214	db_endlp = buffer + size;
215	db_look_char = 0;
216	db_look_token = 0;
217	}
218
219	void
220	db_save_lex_context(register struct db_lex_context *lp)
221	{
222	lp->l_ptr = db_lp;
223	lp->l_eptr = db_endlp;
224	lp->l_char = db_look_char;
225	lp->l_token = db_look_token;
226	}
227
228	void
229	db_restore_lex_context(register struct db_lex_context *lp)
230	{
231	db_lp = lp->l_ptr;
232	db_last_lp = db_lp;
233	db_endlp = lp->l_eptr;
234	db_look_char = lp->l_char;
235	db_look_token = lp->l_token;
236	}
237
238	int
239	db_read_char(void)
240	{
241	int c;
242
243	if (db_look_char != 0) {
244	c = db_look_char;
245	db_look_char = 0;
246	}
247	else if (db_lp >= db_endlp)
248	c = -1;
249	else
250	c = *db_lp++;
251	return (c);
252	}
253
254	void
255	db_unread_char(int c)
256	{
257	db_look_char = c;
258	}
259
260	void
261	db_unread_token(int t)
262	{
263	db_look_token = t;
264	}
265
266	int
267	db_read_token(void)
268	{
269	int t;
270
271	if (db_look_token) {
272	t = db_look_token;
273	db_look_token = 0;
274	}
275	else {
276	db_last_lp = db_lp;
277	if (db_look_char)
278	db_last_lp--;
279	t = db_lex();
280	}
281	return (t);
282	}
283
284	db_expr_t db_tok_number;
285	char db_tok_string[TOK_STRING_SIZE];
286
287	db_expr_t db_radix = 16;
288
289	void
290	db_flush_lex(void)
291	{
292	db_flush_line();
293	db_look_char = 0;
294	db_look_token = 0;
295	}
296
297	#define DB_DISP_SKIP 40 /* number of chars to display skip */
298
299	void
300	db_skip_to_eol(void)
301	{
302	register int skip;
303	register int t;
304	register int n;
305	register char *p;
306
307	t = db_read_token();
308	p = db_last_lp;
309	for (skip = 0; t != tEOL && t != tSEMI_COLON && t != tEOF; skip++)
310	t = db_read_token();
311	if (t == tSEMI_COLON)
312	db_unread_token(t);
313	if (skip != 0) {
314	while (p < db_last_lp && (p == ' ' \|\| p == '\t'))
315	p++;
316	db_printf("Warning: Skipped input data \"");
317	for (n = 0; n < DB_DISP_SKIP && p < db_last_lp; n++)
318	db_printf("%c", *p++);
319	if (n >= DB_DISP_SKIP)
320	db_printf("....");
321	db_printf("\"\n");
322	}
323	}
324
325	int
326	db_lex(void)
327	{
328	register char *cp;
329	register int c;
330
331	c = db_read_char();
332	while (c <= ' ' \|\| c > '~') {
333	if (c == '\n' \|\| c == -1)
334	return (tEOL);
335	c = db_read_char();
336	}
337
338	cp = db_tok_string;
339	*cp++ = c;
340
341	if (c >= '0' && c <= '9') {
342	/* number */
343	int r, digit;
344
345	if (c > '0')
346	r = db_radix;
347	else {
348	c = db_read_char();
349	if (c == 'O' \|\| c == 'o')
350	r = 8;
351	else if (c == 'T' \|\| c == 't')
352	r = 10;
353	else if (c == 'X' \|\| c == 'x')
354	r = 16;
355	else {
356	cp--;
357	r = db_radix;
358	db_unread_char(c);
359	}
360	c = db_read_char();
361	*cp++ = c;
362	}
363	db_tok_number = 0;
364	for (;;) {
365	if (c >= '0' && c <= ((r == 8) ? '7' : '9'))
366	digit = c - '0';
367	else if (r == 16 && ((c >= 'A' && c <= 'F') \|\|
368	(c >= 'a' && c <= 'f'))) {
369	if (c >= 'a')
370	digit = c - 'a' + 10;
371	else
372	digit = c - 'A' + 10;
373	}
374	else
375	break;
376	db_tok_number = db_tok_number * r + digit;
377	c = db_read_char();
378	if (cp < &db_tok_string[sizeof(db_tok_string)-1])
379	*cp++ = c;
380	}
381	cp[-1] = 0;
382	if ((c >= '0' && c <= '9') \|\|
383	(c >= 'A' && c <= 'Z') \|\|
384	(c >= 'a' && c <= 'z') \|\|
385	(c == '_'))
386	{
387	db_printf("Bad character '%c' after number %s\n",
388	c, db_tok_string);
389	db_error(0);
390	db_flush_lex();
391	return (tEOF);
392	}
393	db_unread_char(c);
394	return (tNUMBER);
395	}
396	if ((c >= 'A' && c <= 'Z') \|\|
397	(c >= 'a' && c <= 'z') \|\|
398	c == '_' \|\| c == '\\' \|\| c == ':')
399	{
400	/* identifier */
401	if (c == '\\') {
402	c = db_read_char();
403	if (c == '\n' \|\| c == -1)
404	db_error("Bad '\\' at the end of line\n");
405	cp[-1] = c;
406	}
407	while (1) {
408	c = db_read_char();
409	if ((c >= 'A' && c <= 'Z') \|\|
410	(c >= 'a' && c <= 'z') \|\|
411	(c >= '0' && c <= '9') \|\|
412	c == '_' \|\| c == '\\' \|\| c == ':' \|\| c == '.')
413	{
414	if (c == '\\') {
415	c = db_read_char();
416	if (c == '\n' \|\| c == -1)
417	db_error("Bad '\\' at the end of line\n");
418	}
419	*cp++ = c;
420	if (cp == db_tok_string+sizeof(db_tok_string)) {
421	db_error("String too long\n");
422	db_flush_lex();
423	return (tEOF);
424	}
425	continue;
426	}
427	else {
428	*cp = '\0';
429	break;
430	}
431	}
432	db_unread_char(c);
433	return (tIDENT);
434	}
435
436	*cp = 0;
437	switch (c) {
438	case '+':
439	return (tPLUS);
440	case '-':
441	return (tMINUS);
442	case '.':
443	c = db_read_char();
444	if (c == '.') {
445	*cp++ = c;
446	*cp = 0;
447	return (tDOTDOT);
448	}
449	db_unread_char(c);
450	return (tDOT);
451	case '*':
452	return (tSTAR);
453	case '/':
454	return (tSLASH);
455	case '=':
456	c = db_read_char();
457	if (c == '=') {
458	*cp++ = c;
459	*cp = 0;
460	return(tLOG_EQ);
461	}
462	db_unread_char(c);
463	return (tEQ);
464	case '%':
465	return (tPCT);
466	case '#':
467	return (tHASH);
468	case '(':
469	return (tLPAREN);
470	case ')':
471	return (tRPAREN);
472	case ',':
473	return (tCOMMA);
474	case '\'':
475	return (tQUOTE);
476	case '"':
477	/* string */
478	cp = db_tok_string;
479	c = db_read_char();
480	while (c != '"' && c > 0 && c != '\n') {
481	if (cp >= &db_tok_string[sizeof(db_tok_string)-1]) {
482	db_error("Too long string\n");
483	db_flush_lex();
484	return (tEOF);
485	}
486	if (c == '\\') {
487	c = db_read_char();
488	switch(c) {
489	case 'n':
490	c = '\n'; break;
491	case 't':
492	c = '\t'; break;
493	case '\\':
494	case '"':
495	break;
496	default:
497	db_printf("Bad escape sequence '\\%c'\n", c);
498	db_error(0);
499	db_flush_lex();
500	return (tEOF);
501	}
502	}
503	*cp++ = c;
504	c = db_read_char();
505	}
506	*cp = 0;
507	if (c != '"') {
508	db_error("Non terminated string constant\n");
509	db_flush_lex();
510	return (tEOF);
511	}
512	return (tSTRING);
513	case '$':
514	return (tDOLLAR);
515	case '!':
516	c = db_read_char();
517	if (c == '=') {
518	*cp++ = c;
519	*cp = 0;
520	return(tLOG_NOT_EQ);
521	}
522	db_unread_char(c);
523	return (tEXCL);
524	case '&':
525	c = db_read_char();
526	if (c == '&') {
527	*cp++ = c;
528	*cp = 0;
529	return(tLOG_AND);
530	}
531	db_unread_char(c);
532	return(tBIT_AND);
533	case '\|':
534	c = db_read_char();
535	if (c == '\|') {
536	*cp++ = c;
537	*cp = 0;
538	return(tLOG_OR);
539	}
540	db_unread_char(c);
541	return(tBIT_OR);
542	case '<':
543	c = db_read_char();
544	*cp++ = c;
545	*cp = 0;
546	if (c == '<')
547	return (tSHIFT_L);
548	if (c == '=')
549	return (tLESS_EQ);
550	cp[-1] = 0;
551	db_unread_char(c);
552	return(tLESS);
553	break;
554	case '>':
555	c = db_read_char();
556	*cp++ = c;
557	*cp = 0;
558	if (c == '>')
559	return (tSHIFT_R);
560	if (c == '=')
561	return (tGREATER_EQ);
562	cp[-1] = 0;
563	db_unread_char(c);
564	return (tGREATER);
565	break;
566	case ';':
567	return (tSEMI_COLON);
568	case '?':
569	return (tQUESTION);
570	case -1:
571	strcpy(db_tok_string, "<EOL>");
572	return (tEOF);
573	}
574	db_printf("Bad character '%c'\n", c);
575	db_flush_lex();
576	return (tEOF);
577	}