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Diffstat (limited to 'src/pluto/lex.c')
| -rw-r--r-- | src/pluto/lex.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/src/pluto/lex.c b/src/pluto/lex.c new file mode 100644 index 000000000..5c811725a --- /dev/null +++ b/src/pluto/lex.c @@ -0,0 +1,213 @@ +/* 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. + * + * RCSID $Id: lex.c,v 1.1 2004/03/15 20:35:28 as Exp $ + */ + +#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; + } +} |