[become] / src / lexer.l

/* -*-c-*-
 *
 * $Id: lexer.l,v 1.4 1999/05/04 16:17:26 mdw Exp $
 *
 * Lexical analyser for `become.conf' files
 *
 * (c) 1998 EBI
 */

/*----- Licensing notice --------------------------------------------------*
 *
 * This file is part of `become'
 *
 * `Become' is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * `Become' is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with `become'; if not, write to the Free Software Foundation,
 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------*
 *
 * $Log: lexer.l,v $
 * Revision 1.4  1999/05/04 16:17:26  mdw
 * Change to header file name for parser.  See log for `parse.h' for
 * details.
 *
 * Revision 1.3  1998/01/12  16:46:07  mdw
 * Fix copyright date.
 *
 * Revision 1.2  1997/08/04 10:24:23  mdw
 * Sources placed under CVS control.
 *
 * Revision 1.1  1997/07/21  13:47:48  mdw
 * Initial revision
 *
 */

/*----- Declarations section ----------------------------------------------*/

/* --- Header files --- */

%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "become.h"
#include "lexer.h"
#include "parse.h"
#include "utils.h"
%}

/* --- Start conditions --- */

%x s_KEYWORD
%x s_NORMAL
%x s_STRING

/* --- A handy static buffer --- */

 static char lex__buff[4096];
 static char *lex__ptr;

/* --- Line number --- */

 int lex_line;

%%

 /*---- Main scanner definition -------------------------------------------*/

 /* --- Comments --- */

<INITIAL,s_KEYWORD,s_NORMAL>{
  "#".*\n			lex_line++;

 /* --- Whitespace --- */

  [ \t]				/* munch */
  \n				lex_line++;
}

 /* --- Keywords --- */

<INITIAL,s_KEYWORD>{
  user				BEGIN(s_NORMAL); return (USER);
  command			BEGIN(s_NORMAL); return (COMMAND);
  host				BEGIN(s_NORMAL); return (HOST);
  allow				BEGIN(s_NORMAL); return (ALLOW);
  port				BEGIN(s_NORMAL); return (PORT);
  keyfile			BEGIN(s_NORMAL); return (KEYFILE);
  .				BEGIN(s_NORMAL); return (BADTOKEN);
}
 /* --- Other sorts of tokens --- */

<s_NORMAL>{
  [0-9]*			yylval.i = atoi(yytext); return (INT);
  [a-zA-Z_][a-zA-Z_0-9]*	yylval.s = yytext; return (WORD);
  \"				BEGIN(s_STRING); lex__ptr = lex__buff;
  ";"				BEGIN(s_KEYWORD); return (';');
  "->"				return (ARROW);
  .				return (yytext[0]);
}

 /* --- Strings and things --- *
  *
  * Be a little careful about buffer overflows here.
  */

<s_STRING>{
  \\.				{
				  if (lex__ptr >
				      lex__buff + sizeof(lex__buff) - 8) {
				    moan("string too long at line %i",
					 lex_line);
				    *lex__ptr++ = 0;
				    yylval.s = lex__buff;
				    BEGIN(s_NORMAL);
				    return (STRING);
				  }
				  *lex__ptr++ = yytext[1];
				}
  \"				{
				  *lex__ptr++ = 0;
				  yylval.s = lex__buff;
				  BEGIN(s_NORMAL);
				  return (STRING);
				}
  \n				|
  <<EOF>>			{
				  moan("missing `\"', inserted at line %i",
				       lex_line);
				  lex_line++;
				  *lex__ptr++ = 0;
				  yylval.s = lex__buff;
				  BEGIN(s_NORMAL);
				  return (STRING);
				}
  .				{
				  if (lex__ptr >
				      lex__buff + sizeof(lex__buff) - 8) {
				    moan("string too long at line %i",
					 lex_line);
				    *lex__ptr++ = 0;
				    yylval.s = lex__buff;
				    BEGIN(s_NORMAL);
				    return (STRING);
				  }
				  *lex__ptr++ = yytext[0];
				}
}

%%

/*----- Support routines --------------------------------------------------*/

/* --- @lexer_scan@ --- *
 *
 * Arguments:	@FILE *fp@ = pointer to a stream object to scan
 *
 * Returns:	---
 *
 * Use:		Initialises the scanner ready to parse from the given
 *		stream.
 */

void lexer_scan(FILE *fp)
{
  yyin = fp;
  lex_line = 1;
  BEGIN(INITIAL);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
c4f2d992	1	/* --c--
c4f2d992	2	*
79fae27d	3	* $Id: lexer.l,v 1.4 1999/05/04 16:17:26 mdw Exp $
c4f2d992	4	*
	5	* Lexical analyser for `become.conf' files
	6	*
c758e654	7	* (c) 1998 EBI
c4f2d992	8	*/
c4f2d992	9
03f996bd	10	/----- Licensing notice --------------------------------------------------
c4f2d992	11	*
	12	* This file is part of `become'
	13	*
	14	* `Become' is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* `Become' is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
03f996bd	25	* along with `become'; if not, write to the Free Software Foundation,
03f996bd	26	* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
c4f2d992	27	*/
	28
	29	/----- Revision history --------------------------------------------------
	30	*
	31	* $Log: lexer.l,v $
79fae27d	32	* Revision 1.4 1999/05/04 16:17:26 mdw
	33	* Change to header file name for parser. See log for `parse.h' for
	34	* details.
	35	*
	36	* Revision 1.3 1998/01/12 16:46:07 mdw
c758e654	37	* Fix copyright date.
c758e654	38	*
03f996bd	39	* Revision 1.2 1997/08/04 10:24:23 mdw
	40	* Sources placed under CVS control.
	41	*
	42	* Revision 1.1 1997/07/21 13:47:48 mdw
c4f2d992	43	* Initial revision
	44	*
	45	*/
	46
	47	/----- Declarations section ----------------------------------------------/
	48
	49	/* --- Header files --- */
	50
	51	%{
	52	#include <stdio.h>
	53	#include <stdlib.h>
	54	#include <string.h>
	55
	56	#include "become.h"
	57	#include "lexer.h"
79fae27d	58	#include "parse.h"
c4f2d992	59	#include "utils.h"
	60	%}
	61
	62	/* --- Start conditions --- */
	63
	64	%x s_KEYWORD
	65	%x s_NORMAL
	66	%x s_STRING
	67
	68	/* --- A handy static buffer --- */
	69
	70	static char lex__buff[4096];
	71	static char *lex__ptr;
	72
	73	/* --- Line number --- */
	74
	75	int lex_line;
	76
	77	%%
	78
	79	/---- Main scanner definition -------------------------------------------/
	80
	81	/* --- Comments --- */
	82
	83	<INITIAL,s_KEYWORD,s_NORMAL>{
	84	"#".*\n lex_line++;
	85
	86	/* --- Whitespace --- */
	87
	88	[ \t] /* munch */
	89	\n lex_line++;
	90	}
	91
	92	/* --- Keywords --- */
	93
	94	<INITIAL,s_KEYWORD>{
	95	user BEGIN(s_NORMAL); return (USER);
	96	command BEGIN(s_NORMAL); return (COMMAND);
	97	host BEGIN(s_NORMAL); return (HOST);
	98	allow BEGIN(s_NORMAL); return (ALLOW);
	99	port BEGIN(s_NORMAL); return (PORT);
	100	keyfile BEGIN(s_NORMAL); return (KEYFILE);
	101	. BEGIN(s_NORMAL); return (BADTOKEN);
	102	}
	103	/* --- Other sorts of tokens --- */
	104
	105	<s_NORMAL>{
	106	[0-9]* yylval.i = atoi(yytext); return (INT);
	107	[a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD);
	108	\" BEGIN(s_STRING); lex__ptr = lex__buff;
	109	";" BEGIN(s_KEYWORD); return (';');
	110	"->" return (ARROW);
	111	. return (yytext[0]);
	112	}
	113
	114	/* --- Strings and things --- *
	115	*
	116	* Be a little careful about buffer overflows here.
	117	*/
	118
	119	<s_STRING>{
	120	\\. {
	121	if (lex__ptr >
	122	lex__buff + sizeof(lex__buff) - 8) {
123	moan("string too long at line %i",
124	lex_line);
125	*lex__ptr++ = 0;
126	yylval.s = lex__buff;
127	BEGIN(s_NORMAL);
128	return (STRING);
129	}
130	*lex__ptr++ = yytext[1];
131	}
132	\" {
133	*lex__ptr++ = 0;
134	yylval.s = lex__buff;
135	BEGIN(s_NORMAL);
136	return (STRING);
137	}
138	\n \|
139	<<EOF>> {
140	moan("missing `\"', inserted at line %i",
141	lex_line);
142	lex_line++;
143	*lex__ptr++ = 0;
144	yylval.s = lex__buff;
145	BEGIN(s_NORMAL);
146	return (STRING);
147	}
148	. {
149	if (lex__ptr >
150	lex__buff + sizeof(lex__buff) - 8) {
151	moan("string too long at line %i",
152	lex_line);
153	*lex__ptr++ = 0;
154	yylval.s = lex__buff;
155	BEGIN(s_NORMAL);
156	return (STRING);
157	}
158	*lex__ptr++ = yytext[0];
159	}
160	}
161
162	%%
163
164	/----- Support routines --------------------------------------------------/
165
166	/* --- @lexer_scan@ --- *
167	*
168	* Arguments: @FILE *fp@ = pointer to a stream object to scan
169	*
170	* Returns: ---
171	*
172	* Use: Initialises the scanner ready to parse from the given
173	* stream.
174	*/
175
176	void lexer_scan(FILE *fp)
177	{
178	yyin = fp;
179	lex_line = 1;
180	BEGIN(INITIAL);
181	}
182
183	/----- That's all, folks -------------------------------------------------/