lex.c

bind 9.3结合mysql数据库

/*
 * Copyright (C) 2004  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 1998-2003  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: lex.c,v 1.66.2.6.2.8 2004/08/28 06:25:21 marka Exp $ */

#include <config.h>

#include <ctype.h>
#include <errno.h>
#include <stdlib.h>

#include <isc/buffer.h>
#include <isc/file.h>
#include <isc/lex.h>
#include <isc/mem.h>
#include <isc/msgs.h>
#include <isc/parseint.h>
#include <isc/print.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/util.h>

typedef struct inputsource {
	isc_result_t			result;
	isc_boolean_t			is_file;
	isc_boolean_t			need_close;
	isc_boolean_t			at_eof;
	isc_buffer_t *			pushback;
	unsigned int			ignored;
	void *				input;
	char *				name;
	unsigned long			line;
	unsigned long			saved_line;
	ISC_LINK(struct inputsource)	link;
} inputsource;

#define LEX_MAGIC			ISC_MAGIC('L', 'e', 'x', '!')
#define VALID_LEX(l)			ISC_MAGIC_VALID(l, LEX_MAGIC)

struct isc_lex {
	/* Unlocked. */
	unsigned int			magic;
	isc_mem_t *			mctx;
	size_t				max_token;
	char *				data;
	unsigned int			comments;
	isc_boolean_t			comment_ok;
	isc_boolean_t			last_was_eol;
	unsigned int			paren_count;
	unsigned int			saved_paren_count;
	isc_lexspecials_t		specials;
	LIST(struct inputsource)	sources;
};

static inline isc_result_t
grow_data(isc_lex_t *lex, size_t *remainingp, char **currp, char **prevp) {
	char *new;

	new = isc_mem_get(lex->mctx, lex->max_token * 2 + 1);
	if (new == NULL)
		return (ISC_R_NOMEMORY);
	memcpy(new, lex->data, lex->max_token + 1);
	*currp = new + (*currp - lex->data);
	if (*prevp != NULL)
		*prevp = new + (*prevp - lex->data);
	isc_mem_put(lex->mctx, lex->data, lex->max_token + 1);
	lex->data = new;
	*remainingp += lex->max_token;
	lex->max_token *= 2;
	return (ISC_R_SUCCESS);
}

isc_result_t
isc_lex_create(isc_mem_t *mctx, size_t max_token, isc_lex_t **lexp) {
	isc_lex_t *lex;

	/*
	 * Create a lexer.
	 */

	REQUIRE(lexp != NULL && *lexp == NULL);
	REQUIRE(max_token > 0U);

	lex = isc_mem_get(mctx, sizeof(*lex));
	if (lex == NULL)
		return (ISC_R_NOMEMORY);
	lex->data = isc_mem_get(mctx, max_token + 1);
	if (lex->data == NULL) {
		isc_mem_put(mctx, lex, sizeof(*lex));
		return (ISC_R_NOMEMORY);
	}
	lex->mctx = mctx;
	lex->max_token = max_token;
	lex->comments = 0;
	lex->comment_ok = ISC_TRUE;
	lex->last_was_eol = ISC_TRUE;
	lex->paren_count = 0;
	lex->saved_paren_count = 0;
	memset(lex->specials, 0, 256);
	INIT_LIST(lex->sources);
	lex->magic = LEX_MAGIC;

	*lexp = lex;

	return (ISC_R_SUCCESS);
}

void
isc_lex_destroy(isc_lex_t **lexp) {
	isc_lex_t *lex;

	/*
	 * Destroy the lexer.
	 */

	REQUIRE(lexp != NULL);
	lex = *lexp;
	REQUIRE(VALID_LEX(lex));

	while (!EMPTY(lex->sources))
		RUNTIME_CHECK(isc_lex_close(lex) == ISC_R_SUCCESS);
	if (lex->data != NULL)
		isc_mem_put(lex->mctx, lex->data, lex->max_token + 1);
	lex->magic = 0;
	isc_mem_put(lex->mctx, lex, sizeof(*lex));

	*lexp = NULL;
}

unsigned int
isc_lex_getcomments(isc_lex_t *lex) {
	/*
	 * Return the current lexer commenting styles.
	 */

	REQUIRE(VALID_LEX(lex));

	return (lex->comments);
}

void
isc_lex_setcomments(isc_lex_t *lex, unsigned int comments) {
	/*
	 * Set allowed lexer commenting styles.
	 */

	REQUIRE(VALID_LEX(lex));

	lex->comments = comments;
}

void
isc_lex_getspecials(isc_lex_t *lex, isc_lexspecials_t specials) {
	/*
	 * Put the current list of specials into 'specials'.
	 */

	REQUIRE(VALID_LEX(lex));

	memcpy(specials, lex->specials, 256);
}

void
isc_lex_setspecials(isc_lex_t *lex, isc_lexspecials_t specials) {
	/*
	 * The characters in 'specials' are returned as tokens.  Along with
	 * whitespace, they delimit strings and numbers.
	 */

	REQUIRE(VALID_LEX(lex));

	memcpy(lex->specials, specials, 256);
}

static inline isc_result_t
new_source(isc_lex_t *lex, isc_boolean_t is_file, isc_boolean_t need_close,
	   void *input, const char *name)
{
	inputsource *source;
	isc_result_t result;

	source = isc_mem_get(lex->mctx, sizeof(*source));
	if (source == NULL)
		return (ISC_R_NOMEMORY);
	source->result = ISC_R_SUCCESS;
	source->is_file = is_file;
	source->need_close = need_close;
	source->at_eof = ISC_FALSE;
	source->input = input;
	source->name = isc_mem_strdup(lex->mctx, name);
	if (source->name == NULL) {
		isc_mem_put(lex->mctx, source, sizeof(*source));
		return (ISC_R_NOMEMORY);
	}
	source->pushback = NULL;
	result = isc_buffer_allocate(lex->mctx, &source->pushback,
				     lex->max_token);
	if (result != ISC_R_SUCCESS) {
		isc_mem_free(lex->mctx, source->name);
		isc_mem_put(lex->mctx, source, sizeof(*source));
		return (result);
	}
	source->ignored = 0;
	source->line = 1;
	ISC_LIST_INITANDPREPEND(lex->sources, source, link);

	return (ISC_R_SUCCESS);
}

isc_result_t
isc_lex_openfile(isc_lex_t *lex, const char *filename) {
	isc_result_t result;
	FILE *stream = NULL;

	/*
	 * Open 'filename' and make it the current input source for 'lex'.
	 */

	REQUIRE(VALID_LEX(lex));

	result = isc_stdio_open(filename, "r", &stream);
	if (result != ISC_R_SUCCESS)
		return (result);

	result = new_source(lex, ISC_TRUE, ISC_TRUE, stream, filename);
	if (result != ISC_R_SUCCESS)
		(void)fclose(stream);
	return (result);
}

isc_result_t
isc_lex_openstream(isc_lex_t *lex, FILE *stream) {
	char name[128];

	/*
	 * Make 'stream' the current input source for 'lex'.
	 */

	REQUIRE(VALID_LEX(lex));

	snprintf(name, sizeof(name), "stream-%p", stream);

	return (new_source(lex, ISC_TRUE, ISC_FALSE, stream, name));
}

isc_result_t
isc_lex_openbuffer(isc_lex_t *lex, isc_buffer_t *buffer) {
	char name[128];

	/*
	 * Make 'buffer' the current input source for 'lex'.
	 */

	REQUIRE(VALID_LEX(lex));

	snprintf(name, sizeof(name), "buffer-%p", buffer);

	return (new_source(lex, ISC_FALSE, ISC_FALSE, buffer, name));
}

isc_result_t
isc_lex_close(isc_lex_t *lex) {
	inputsource *source;

	/*
	 * Close the most recently opened object (i.e. file or buffer).
	 */

	REQUIRE(VALID_LEX(lex));

	source = HEAD(lex->sources);
	if (source == NULL)
		return (ISC_R_NOMORE);

	ISC_LIST_UNLINK(lex->sources, source, link);
	if (source->is_file) {
		if (source->need_close)
			(void)fclose((FILE *)(source->input));
	}
	isc_mem_free(lex->mctx, source->name);
	isc_buffer_free(&source->pushback);
	isc_mem_put(lex->mctx, source, sizeof(*source));

	return (ISC_R_SUCCESS);
}

typedef enum {
	lexstate_start,
	lexstate_crlf,
	lexstate_string,
	lexstate_number,
	lexstate_maybecomment,
	lexstate_ccomment,
	lexstate_ccommentend,
	lexstate_eatline,
	lexstate_qstring
} lexstate;

#define IWSEOL (ISC_LEXOPT_INITIALWS | ISC_LEXOPT_EOL)

static void
pushback(inputsource *source, int c) {
	REQUIRE(source->pushback->current > 0);
	if (c == EOF) {
		source->at_eof = ISC_FALSE;
		return;
	}
	source->pushback->current--;
	if (c == '\n')
		source->line--;
}

static isc_result_t
pushandgrow(isc_lex_t *lex, inputsource *source, int c) {
	if (isc_buffer_availablelength(source->pushback) == 0) {
		isc_buffer_t *tbuf = NULL;
		unsigned int oldlen;
		isc_region_t used;
		isc_result_t result;

		oldlen = isc_buffer_length(source->pushback);
		result = isc_buffer_allocate(lex->mctx, &tbuf, oldlen * 2);
		if (result != ISC_R_SUCCESS)
			return (result);
		isc_buffer_usedregion(source->pushback, &used);
		result = isc_buffer_copyregion(tbuf, &used);
		INSIST(result == ISC_R_SUCCESS);
		tbuf->current = source->pushback->current;
		isc_buffer_free(&source->pushback);
		source->pushback = tbuf;
	}
	isc_buffer_putuint8(source->pushback, (isc_uint8_t)c);
	return (ISC_R_SUCCESS);
}

isc_result_t
isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp) {
	inputsource *source;
	int c;
	isc_boolean_t done = ISC_FALSE;
	isc_boolean_t no_comments = ISC_FALSE;
	isc_boolean_t escaped = ISC_FALSE;
	lexstate state = lexstate_start;
	lexstate saved_state = lexstate_start;
	isc_buffer_t *buffer;
	FILE *stream;
	char *curr, *prev;
	size_t remaining;
	isc_uint32_t as_ulong;
	unsigned int saved_options;
	isc_result_t result;

	/*
	 * Get the next token.
	 */

	REQUIRE(VALID_LEX(lex));
	source = HEAD(lex->sources);
	REQUIRE(tokenp != NULL);

	lex->saved_paren_count = lex->paren_count;
	source->saved_line = source->line;

	if (source == NULL) {
		if ((options & ISC_LEXOPT_NOMORE) != 0) {
			tokenp->type = isc_tokentype_nomore;
			return (ISC_R_SUCCESS);
		}
		return (ISC_R_NOMORE);
	}

	if (source->result != ISC_R_SUCCESS)
		return (source->result);

	if (isc_buffer_remaininglength(source->pushback) == 0 &&
	    source->at_eof)
	{
		if ((options & ISC_LEXOPT_DNSMULTILINE) != 0 &&
		    lex->paren_count != 0) {
			lex->paren_count = 0;
			return (ISC_R_UNBALANCED);
		}
		if ((options & ISC_LEXOPT_EOF) != 0) {
			tokenp->type = isc_tokentype_eof;
			return (ISC_R_SUCCESS);
		}
		return (ISC_R_EOF);
	}

	isc_buffer_compact(source->pushback);

	saved_options = options;
	if ((options & ISC_LEXOPT_DNSMULTILINE) != 0 && lex->paren_count > 0)
		options &= ~IWSEOL;

	curr = lex->data;
	*curr = '\0';

	prev = NULL;
	remaining = lex->max_token;

#ifdef HAVE_FLOCKFILE
	if (source->is_file)
		flockfile(source->input);
#endif

	do {
		if (isc_buffer_remaininglength(source->pushback) == 0) {
			if (source->is_file) {
				stream = source->input;

#if defined(HAVE_FLOCKFILE) && defined(HAVE_GETCUNLOCKED)
				c = getc_unlocked(stream);
#else
				c = getc(stream);
#endif
				if (c == EOF) {
					if (ferror(stream)) {
						source->result = ISC_R_IOERROR;
						result = source->result;
						goto done;
					}
					source->at_eof = ISC_TRUE;
				}
			} else {
				buffer = source->input;

				if (buffer->current == buffer->used) {
					c = EOF;
					source->at_eof = ISC_TRUE;
				} else {
					c = *((char *)buffer->base +
					      buffer->current);
					buffer->current++;
				}
			}
			if (c != EOF) {
				source->result = pushandgrow(lex, source, c);
				if (source->result != ISC_R_SUCCESS) {
					result = source->result;
					goto done;
				}
			}
		}

		if (!source->at_eof) {
			if (state == lexstate_start)