[become] / src / lexer.l

/* -*-c-*-
 *
 * $Id: lexer.l,v 1.5 2003/10/12 00:29:10 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 1.5  2003/10/12 00:29:10  mdw
 * Missed an old include...
 *
 * 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"
%}

/* --- 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	*
892c65ca	3	* $Id: lexer.l,v 1.5 2003/10/12 00:29:10 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 $
892c65ca	32	* Revision 1.5 2003/10/12 00:29:10 mdw
	33	* Missed an old include...
	34	*
79fae27d	35	* Revision 1.4 1999/05/04 16:17:26 mdw
	36	* Change to header file name for parser. See log for `parse.h' for
	37	* details.
	38	*
	39	* Revision 1.3 1998/01/12 16:46:07 mdw
c758e654	40	* Fix copyright date.
c758e654	41	*
03f996bd	42	* Revision 1.2 1997/08/04 10:24:23 mdw
	43	* Sources placed under CVS control.
	44	*
	45	* Revision 1.1 1997/07/21 13:47:48 mdw
c4f2d992	46	* Initial revision
	47	*
	48	*/
	49
	50	/----- Declarations section ----------------------------------------------/
	51
	52	/* --- Header files --- */
	53
	54	%{
	55	#include <stdio.h>
	56	#include <stdlib.h>
	57	#include <string.h>
	58
	59	#include "become.h"
	60	#include "lexer.h"
79fae27d	61	#include "parse.h"
c4f2d992	62	%}
	63
	64	/* --- Start conditions --- */
	65
	66	%x s_KEYWORD
	67	%x s_NORMAL
	68	%x s_STRING
	69
	70	/* --- A handy static buffer --- */
	71
	72	static char lex__buff[4096];
	73	static char *lex__ptr;
	74
	75	/* --- Line number --- */
	76
	77	int lex_line;
	78
	79	%%
	80
	81	/---- Main scanner definition -------------------------------------------/
	82
	83	/* --- Comments --- */
	84
	85	<INITIAL,s_KEYWORD,s_NORMAL>{
	86	"#".*\n lex_line++;
	87
	88	/* --- Whitespace --- */
	89
	90	[ \t] /* munch */
	91	\n lex_line++;
	92	}
	93
	94	/* --- Keywords --- */
	95
	96	<INITIAL,s_KEYWORD>{
	97	user BEGIN(s_NORMAL); return (USER);
	98	command BEGIN(s_NORMAL); return (COMMAND);
	99	host BEGIN(s_NORMAL); return (HOST);
	100	allow BEGIN(s_NORMAL); return (ALLOW);
	101	port BEGIN(s_NORMAL); return (PORT);
	102	keyfile BEGIN(s_NORMAL); return (KEYFILE);
	103	. BEGIN(s_NORMAL); return (BADTOKEN);
	104	}
	105	/* --- Other sorts of tokens --- */
	106
	107	<s_NORMAL>{
	108	[0-9]* yylval.i = atoi(yytext); return (INT);
	109	[a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD);
	110	\" BEGIN(s_STRING); lex__ptr = lex__buff;
	111	";" BEGIN(s_KEYWORD); return (';');
	112	"->" return (ARROW);
	113	. return (yytext[0]);
	114	}
	115
	116	/* --- Strings and things --- *
	117	*
	118	* Be a little careful about buffer overflows here.
	119	*/
	120
	121	<s_STRING>{
	122	\\. {
	123	if (lex__ptr >
	124	lex__buff + sizeof(lex__buff) - 8) {
	125	moan("string too long at line %i",
126	lex_line);
127	*lex__ptr++ = 0;
128	yylval.s = lex__buff;
129	BEGIN(s_NORMAL);
130	return (STRING);
131	}
132	*lex__ptr++ = yytext[1];
133	}
134	\" {
135	*lex__ptr++ = 0;
136	yylval.s = lex__buff;
137	BEGIN(s_NORMAL);
138	return (STRING);
139	}
140	\n \|
141	<<EOF>> {
142	moan("missing `\"', inserted at line %i",
143	lex_line);
144	lex_line++;
145	*lex__ptr++ = 0;
146	yylval.s = lex__buff;
147	BEGIN(s_NORMAL);
148	return (STRING);
149	}
150	. {
151	if (lex__ptr >
152	lex__buff + sizeof(lex__buff) - 8) {
153	moan("string too long at line %i",
154	lex_line);
155	*lex__ptr++ = 0;
156	yylval.s = lex__buff;
157	BEGIN(s_NORMAL);
158	return (STRING);
159	}
160	*lex__ptr++ = yytext[0];
161	}
162	}
163
164	%%
165
166	/----- Support routines --------------------------------------------------/
167
168	/* --- @lexer_scan@ --- *
169	*
170	* Arguments: @FILE *fp@ = pointer to a stream object to scan
171	*
172	* Returns: ---
173	*
174	* Use: Initialises the scanner ready to parse from the given
175	* stream.
176	*/
177
178	void lexer_scan(FILE *fp)
179	{
180	yyin = fp;
181	lex_line = 1;
182	BEGIN(INITIAL);
183	}
184
185	/----- That's all, folks -------------------------------------------------/