212 lines
4.6 KiB
C
212 lines
4.6 KiB
C
/* lexer (lexical analyzer) for control files
|
|
* Copyright (C) 1998-2001 D. Hugh Redelmeier.
|
|
*
|
|
* This program 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. See <http://www.fsf.org/copyleft/gpl.txt>.
|
|
*
|
|
* This program 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.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
#include <ctype.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
|
|
#include <freeswan.h>
|
|
|
|
#include "constants.h"
|
|
#include "defs.h"
|
|
#include "log.h"
|
|
#include "whack.h" /* for RC_LOG_SERIOUS */
|
|
#include "lex.h"
|
|
|
|
struct file_lex_position *flp = NULL;
|
|
|
|
/* Open a file for lexical processing.
|
|
* new_flp and name must point into storage with will live
|
|
* at least until the file is closed.
|
|
*/
|
|
bool
|
|
lexopen(struct file_lex_position *new_flp, const char *name, bool optional)
|
|
{
|
|
FILE *f = fopen(name, "r");
|
|
|
|
if (f == NULL)
|
|
{
|
|
if (!optional || errno != ENOENT)
|
|
log_errno((e, "could not open \"%s\"", name));
|
|
return FALSE;
|
|
}
|
|
else
|
|
{
|
|
new_flp->previous = flp;
|
|
flp = new_flp;
|
|
flp->filename = name;
|
|
flp->fp = f;
|
|
flp->lino = 0;
|
|
flp->bdry = B_none;
|
|
|
|
flp->cur = flp->buffer; /* nothing loaded yet */
|
|
flp->under = *flp->cur = '\0';
|
|
|
|
(void) shift(); /* prime tok */
|
|
return TRUE;
|
|
}
|
|
}
|
|
|
|
void
|
|
lexclose(void)
|
|
{
|
|
fclose(flp->fp);
|
|
flp = flp->previous;
|
|
}
|
|
|
|
/* Token decoding: shift() loads the next token into tok.
|
|
* Iff a token starts at the left margin, it is considered
|
|
* to be the first in a record. We create a special condition,
|
|
* Record Boundary (analogous to EOF), just before such a token.
|
|
* We are unwilling to shift through a record boundary:
|
|
* it must be overridden first.
|
|
* Returns FALSE iff Record Boundary or EOF (i.e. no token);
|
|
* tok will then be NULL.
|
|
*/
|
|
|
|
char *tok;
|
|
#define tokeq(s) (streq(tok, (s)))
|
|
#define tokeqword(s) (strcasecmp(tok, (s)) == 0)
|
|
|
|
bool
|
|
shift(void)
|
|
{
|
|
char *p = flp->cur;
|
|
char *sor = NULL; /* start of record for any new lines */
|
|
|
|
passert(flp->bdry == B_none);
|
|
|
|
*p = flp->under;
|
|
flp->under = '\0';
|
|
|
|
for (;;)
|
|
{
|
|
switch (*p)
|
|
{
|
|
case '\0': /* end of line */
|
|
case '#': /* comment to end of line: treat as end of line */
|
|
/* get the next line */
|
|
if (fgets(flp->buffer, sizeof(flp->buffer)-1, flp->fp) == NULL)
|
|
{
|
|
flp->bdry = B_file;
|
|
tok = flp->cur = NULL;
|
|
return FALSE;
|
|
}
|
|
else
|
|
{
|
|
/* strip trailing whitespace, including \n */
|
|
|
|
for (p = flp->buffer+strlen(flp->buffer)-1
|
|
; p>flp->buffer && isspace(p[-1]); p--)
|
|
;
|
|
*p = '\0';
|
|
|
|
flp->lino++;
|
|
sor = p = flp->buffer;
|
|
}
|
|
break; /* try again for a token */
|
|
|
|
case ' ': /* whitespace */
|
|
case '\t':
|
|
p++;
|
|
break; /* try again for a token */
|
|
|
|
case '"': /* quoted token */
|
|
case '\'':
|
|
if (p != sor)
|
|
{
|
|
/* we have a quoted token: note and advance to its end */
|
|
tok = p;
|
|
p = strchr(p+1, *p);
|
|
if (p == NULL)
|
|
{
|
|
loglog(RC_LOG_SERIOUS, "\"%s\" line %d: unterminated string"
|
|
, flp->filename, flp->lino);
|
|
p = tok + strlen(tok);
|
|
}
|
|
else
|
|
{
|
|
p++; /* include delimiter in token */
|
|
}
|
|
|
|
/* remember token delimiter and replace with '\0' */
|
|
flp->under = *p;
|
|
*p = '\0';
|
|
flp->cur = p;
|
|
return TRUE;
|
|
}
|
|
/* FALL THROUGH */
|
|
default:
|
|
if (p != sor)
|
|
{
|
|
/* we seem to have a token: note and advance to its end */
|
|
tok = p;
|
|
|
|
if (p[0] == '0' && p[1] == 't')
|
|
{
|
|
/* 0t... token goes to end of line */
|
|
p += strlen(p);
|
|
}
|
|
else
|
|
{
|
|
/* "ordinary" token: up to whitespace or end of line */
|
|
do {
|
|
p++;
|
|
} while (*p != '\0' && !isspace(*p))
|
|
;
|
|
|
|
/* fudge to separate ':' from a preceding adjacent token */
|
|
if (p-1 > tok && p[-1] == ':')
|
|
p--;
|
|
}
|
|
|
|
/* remember token delimiter and replace with '\0' */
|
|
flp->under = *p;
|
|
*p = '\0';
|
|
flp->cur = p;
|
|
return TRUE;
|
|
}
|
|
|
|
/* we have a start-of-record: return it, deferring "real" token */
|
|
flp->bdry = B_record;
|
|
tok = NULL;
|
|
flp->under = *p;
|
|
flp->cur = p;
|
|
return FALSE;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ensures we are at a Record (or File) boundary, optionally warning if not */
|
|
|
|
bool
|
|
flushline(const char *m)
|
|
{
|
|
if (flp->bdry != B_none)
|
|
{
|
|
return TRUE;
|
|
}
|
|
else
|
|
{
|
|
if (m != NULL)
|
|
loglog(RC_LOG_SERIOUS, "\"%s\" line %d: %s", flp->filename, flp->lino, m);
|
|
do {} while (shift());
|
|
return FALSE;
|
|
}
|
|
}
|