[become] / src / lexer.l

/* -*-c-*-
 *
 * $Id: lexer.l,v 1.7 2004/04/08 01:36:20 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.
 */

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

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

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

#include <mLib/report.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	*
af4f4d6a	3	* $Id: lexer.l,v 1.7 2004/04/08 01:36:20 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	*/
c4f2d992	28
c4f2d992	29	/----- Declarations section ----------------------------------------------/
	30
	31	/* --- Header files --- */
	32
	33	%{
	34	#include <stdio.h>
	35	#include <stdlib.h>
	36	#include <string.h>
	37
2344499e	38	#include <mLib/report.h>
2344499e	39
c4f2d992	40	#include "become.h"
c4f2d992	41	#include "lexer.h"
79fae27d	42	#include "parse.h"
c4f2d992	43	%}
	44
	45	/* --- Start conditions --- */
	46
	47	%x s_KEYWORD
	48	%x s_NORMAL
	49	%x s_STRING
	50
	51	/* --- A handy static buffer --- */
	52
	53	static char lex__buff[4096];
	54	static char *lex__ptr;
	55
	56	/* --- Line number --- */
	57
	58	int lex_line;
	59
	60	%%
	61
	62	/---- Main scanner definition -------------------------------------------/
	63
	64	/* --- Comments --- */
	65
	66	<INITIAL,s_KEYWORD,s_NORMAL>{
	67	"#".*\n lex_line++;
	68
	69	/* --- Whitespace --- */
	70
	71	[ \t] /* munch */
	72	\n lex_line++;
	73	}
	74
	75	/* --- Keywords --- */
	76
	77	<INITIAL,s_KEYWORD>{
	78	user BEGIN(s_NORMAL); return (USER);
	79	command BEGIN(s_NORMAL); return (COMMAND);
	80	host BEGIN(s_NORMAL); return (HOST);
	81	allow BEGIN(s_NORMAL); return (ALLOW);
	82	port BEGIN(s_NORMAL); return (PORT);
	83	keyfile BEGIN(s_NORMAL); return (KEYFILE);
	84	. BEGIN(s_NORMAL); return (BADTOKEN);
	85	}
	86	/* --- Other sorts of tokens --- */
	87
	88	<s_NORMAL>{
	89	[0-9]* yylval.i = atoi(yytext); return (INT);
	90	[a-zA-Z_][a-zA-Z_0-9]* yylval.s = yytext; return (WORD);
	91	\" BEGIN(s_STRING); lex__ptr = lex__buff;
	92	";" BEGIN(s_KEYWORD); return (';');
	93	"->" return (ARROW);
	94	. return (yytext[0]);
	95	}
	96
	97	/* --- Strings and things --- *
	98	*
	99	* Be a little careful about buffer overflows here.
	100	*/
	101
	102	<s_STRING>{
	103	\\. {
	104	if (lex__ptr >
	105	lex__buff + sizeof(lex__buff) - 8) {
	106	moan("string too long at line %i",
107	lex_line);
108	*lex__ptr++ = 0;
109	yylval.s = lex__buff;
110	BEGIN(s_NORMAL);
111	return (STRING);
112	}
113	*lex__ptr++ = yytext[1];
114	}
115	\" {
116	*lex__ptr++ = 0;
117	yylval.s = lex__buff;
118	BEGIN(s_NORMAL);
119	return (STRING);
120	}
121	\n \|
122	<<EOF>> {
123	moan("missing `\"', inserted at line %i",
124	lex_line);
125	lex_line++;
126	*lex__ptr++ = 0;
127	yylval.s = lex__buff;
128	BEGIN(s_NORMAL);
129	return (STRING);
130	}
131	. {
132	if (lex__ptr >
133	lex__buff + sizeof(lex__buff) - 8) {
134	moan("string too long at line %i",
135	lex_line);
136	*lex__ptr++ = 0;
137	yylval.s = lex__buff;
138	BEGIN(s_NORMAL);
139	return (STRING);
140	}
141	*lex__ptr++ = yytext[0];
142	}
143	}
144
145	%%
146
147	/----- Support routines --------------------------------------------------/
148
149	/* --- @lexer_scan@ --- *
150	*
151	* Arguments: @FILE *fp@ = pointer to a stream object to scan
152	*
153	* Returns: ---
154	*
155	* Use: Initialises the scanner ready to parse from the given
156	* stream.
157	*/
158
159	void lexer_scan(FILE *fp)
160	{
161	yyin = fp;
162	lex_line = 1;
163	BEGIN(INITIAL);
164	}
165
166	/----- That's all, folks -------------------------------------------------/