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Diffstat (limited to 'lib/isc/include/isc/lex.h')
| -rw-r--r-- | lib/isc/include/isc/lex.h | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/lib/isc/include/isc/lex.h b/lib/isc/include/isc/lex.h new file mode 100644 index 0000000..14b29cf --- /dev/null +++ b/lib/isc/include/isc/lex.h @@ -0,0 +1,444 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * SPDX-License-Identifier: MPL-2.0 + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, you can obtain one at https://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +#pragma once + +/***** +***** Module Info +*****/ + +/*! \file isc/lex.h + * \brief The "lex" module provides a lightweight tokenizer. It can operate + * on files or buffers, and can handle "include". It is designed for + * parsing of DNS master files and the BIND configuration file, but + * should be general enough to tokenize other things, e.g. HTTP. + * + * \li MP: + * No synchronization is provided. Clients must ensure exclusive + * access. + * + * \li Reliability: + * No anticipated impact. + * + * \li Resources: + * TBS + * + * \li Security: + * No anticipated impact. + * + * \li Standards: + * None. + */ + +/*** + *** Imports + ***/ + +#include <stdbool.h> +#include <stdio.h> + +#include <isc/lang.h> +#include <isc/region.h> +#include <isc/types.h> + +ISC_LANG_BEGINDECLS + +/*** + *** Options + ***/ + +/*@{*/ +/*! + * Various options for isc_lex_gettoken(). + */ + +#define ISC_LEXOPT_EOL 0x0001 /*%< Want end-of-line token. */ +#define ISC_LEXOPT_EOF 0x0002 /*%< Want end-of-file token. */ +#define ISC_LEXOPT_INITIALWS 0x0004 /*%< Want initial whitespace. */ +#define ISC_LEXOPT_NUMBER 0x0008 /*%< Recognize numbers. */ +#define ISC_LEXOPT_QSTRING 0x0010 /*%< Recognize qstrings. */ +/*@}*/ + +/*@{*/ +/*! + * The ISC_LEXOPT_DNSMULTILINE option handles the processing of '(' and ')' in + * the DNS master file format. If this option is set, then the + * ISC_LEXOPT_INITIALWS and ISC_LEXOPT_EOL options will be ignored when + * the paren count is > 0. To use this option, '(' and ')' must be special + * characters. + */ +#define ISC_LEXOPT_DNSMULTILINE 0x0020 /*%< Handle '(' and ')'. */ +#define ISC_LEXOPT_NOMORE 0x0040 /*%< Want "no more" token. */ + +#define ISC_LEXOPT_CNUMBER 0x0080 /*%< Recognize octal and hex. */ +#define ISC_LEXOPT_ESCAPE 0x0100 /*%< Recognize escapes. */ +#define ISC_LEXOPT_QSTRINGMULTILINE 0x0200 /*%< Allow multiline "" strings */ +#define ISC_LEXOPT_OCTAL 0x0400 /*%< Expect a octal number. */ +#define ISC_LEXOPT_BTEXT 0x0800 /*%< Bracketed text. */ +#define ISC_LEXOPT_VPAIR 0x1000 /*%< Recognize value pair. */ +#define ISC_LEXOPT_QVPAIR 0x2000 /*%< Recognize quoted value pair. */ +/*@}*/ +/*@{*/ +/*! + * Various commenting styles, which may be changed at any time with + * isc_lex_setcomments(). + */ + +#define ISC_LEXCOMMENT_C 0x01 +#define ISC_LEXCOMMENT_CPLUSPLUS 0x02 +#define ISC_LEXCOMMENT_SHELL 0x04 +#define ISC_LEXCOMMENT_DNSMASTERFILE 0x08 +/*@}*/ + +/*** + *** Types + ***/ + +/*! Lex */ + +typedef char isc_lexspecials_t[256]; + +/* Tokens */ + +typedef enum { + isc_tokentype_unknown = 0, + isc_tokentype_string = 1, + isc_tokentype_number = 2, + isc_tokentype_qstring = 3, + isc_tokentype_eol = 4, + isc_tokentype_eof = 5, + isc_tokentype_initialws = 6, + isc_tokentype_special = 7, + isc_tokentype_nomore = 8, + isc_tokentype_btext = 9, + isc_tokentype_vpair = 10, + isc_tokentype_qvpair = 11, +} isc_tokentype_t; + +typedef union { + char as_char; + unsigned long as_ulong; + isc_region_t as_region; + isc_textregion_t as_textregion; + void *as_pointer; +} isc_tokenvalue_t; + +typedef struct isc_token { + isc_tokentype_t type; + isc_tokenvalue_t value; +} isc_token_t; + +/*** + *** Functions + ***/ + +isc_result_t +isc_lex_create(isc_mem_t *mctx, size_t max_token, isc_lex_t **lexp); +/*%< + * Create a lexer. + * + * 'max_token' is a hint of the number of bytes in the largest token. + * + * Requires: + *\li '*lexp' is a valid lexer. + * + * Ensures: + *\li On success, *lexp is attached to the newly created lexer. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOMEMORY + */ + +void +isc_lex_destroy(isc_lex_t **lexp); +/*%< + * Destroy the lexer. + * + * Requires: + *\li '*lexp' is a valid lexer. + * + * Ensures: + *\li *lexp == NULL + */ + +unsigned int +isc_lex_getcomments(isc_lex_t *lex); +/*%< + * Return the current lexer commenting styles. + * + * Requires: + *\li 'lex' is a valid lexer. + * + * Returns: + *\li The commenting styles which are currently allowed. + */ + +void +isc_lex_setcomments(isc_lex_t *lex, unsigned int comments); +/*%< + * Set allowed lexer commenting styles. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'comments' has meaningful values. + */ + +void +isc_lex_getspecials(isc_lex_t *lex, isc_lexspecials_t specials); +/*%< + * Put the current list of specials into 'specials'. + * + * Requires: + *\li 'lex' is a valid lexer. + */ + +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. + * + * Note: + *\li Comment processing takes precedence over special character + * recognition. + * + * Requires: + *\li 'lex' is a valid lexer. + */ + +isc_result_t +isc_lex_openfile(isc_lex_t *lex, const char *filename); +/*%< + * Open 'filename' and make it the current input source for 'lex'. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li filename is a valid C string. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOMEMORY Out of memory + *\li #ISC_R_NOTFOUND File not found + *\li #ISC_R_NOPERM No permission to open file + *\li #ISC_R_FAILURE Couldn't open file, not sure why + *\li #ISC_R_UNEXPECTED + */ + +isc_result_t +isc_lex_openstream(isc_lex_t *lex, FILE *stream); +/*%< + * Make 'stream' the current input source for 'lex'. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'stream' is a valid C stream. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOMEMORY Out of memory + */ + +isc_result_t +isc_lex_openbuffer(isc_lex_t *lex, isc_buffer_t *buffer); +/*%< + * Make 'buffer' the current input source for 'lex'. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'buffer' is a valid buffer. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOMEMORY Out of memory + */ + +isc_result_t +isc_lex_close(isc_lex_t *lex); +/*%< + * Close the most recently opened object (i.e. file or buffer). + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_NOMORE No more input sources + */ + +isc_result_t +isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp); +/*%< + * Get the next token. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'lex' has an input source. + * + *\li 'options' contains valid options. + * + *\li '*tokenp' is a valid pointer. + * + * Returns: + *\li #ISC_R_SUCCESS + *\li #ISC_R_UNEXPECTEDEND + *\li #ISC_R_NOMEMORY + * + * These two results are returned only if their corresponding lexer + * options are not set. + * + *\li #ISC_R_EOF End of input source + *\li #ISC_R_NOMORE No more input sources + */ + +isc_result_t +isc_lex_getmastertoken(isc_lex_t *lex, isc_token_t *token, + isc_tokentype_t expect, bool eol); +/*%< + * Get the next token from a DNS master file type stream. This is a + * convenience function that sets appropriate options and handles quoted + * strings and end of line correctly for master files. It also ungets + * unexpected tokens. If `eol` is set then expect end-of-line otherwise + * eol is a error. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'token' is a valid pointer + * + * Returns: + * + * \li any return code from isc_lex_gettoken(). + */ + +isc_result_t +isc_lex_getoctaltoken(isc_lex_t *lex, isc_token_t *token, bool eol); +/*%< + * Get the next token from a DNS master file type stream. This is a + * convenience function that sets appropriate options and handles end + * of line correctly for master files. It also ungets unexpected tokens. + * If `eol` is set then expect end-of-line otherwise eol is a error. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'token' is a valid pointer + * + * Returns: + * + * \li any return code from isc_lex_gettoken(). + */ + +void +isc_lex_ungettoken(isc_lex_t *lex, isc_token_t *tokenp); +/*%< + * Unget the current token. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'lex' has an input source. + * + *\li 'tokenp' points to a valid token. + * + *\li There is no ungotten token already. + */ + +void +isc_lex_getlasttokentext(isc_lex_t *lex, isc_token_t *tokenp, isc_region_t *r); +/*%< + * Returns a region containing the text of the last token returned. + * + * Requires: + *\li 'lex' is a valid lexer. + * + *\li 'lex' has an input source. + * + *\li 'tokenp' points to a valid token. + * + *\li A token has been gotten and not ungotten. + */ + +char * +isc_lex_getsourcename(isc_lex_t *lex); +/*%< + * Return the input source name. + * + * Requires: + *\li 'lex' is a valid lexer. + * + * Returns: + * \li source name or NULL if no current source. + *\li result valid while current input source exists. + */ + +unsigned long +isc_lex_getsourceline(isc_lex_t *lex); +/*%< + * Return the input source line number. + * + * Requires: + *\li 'lex' is a valid lexer. + * + * Returns: + *\li Current line number or 0 if no current source. + */ + +isc_result_t +isc_lex_setsourcename(isc_lex_t *lex, const char *name); +/*%< + * Assigns a new name to the input source. + * + * Requires: + * + * \li 'lex' is a valid lexer. + * + * Returns: + * \li #ISC_R_SUCCESS + * \li #ISC_R_NOMEMORY + * \li #ISC_R_NOTFOUND - there are no sources. + */ + +isc_result_t +isc_lex_setsourceline(isc_lex_t *lex, unsigned long line); +/*%< + * Assigns a new line number to the input source. This can be used + * when parsing a buffer that's been excerpted from the middle a file, + * allowing logged messages to display the correct line number, + * rather than the line number within the buffer. + * + * Requires: + * + * \li 'lex' is a valid lexer. + * + * Returns: + * \li #ISC_R_SUCCESS + * \li #ISC_R_NOTFOUND - there are no sources. + */ + +bool +isc_lex_isfile(isc_lex_t *lex); +/*%< + * Return whether the current input source is a file. + * + * Requires: + *\li 'lex' is a valid lexer. + * + * Returns: + * \li #true if the current input is a file, + *\li #false otherwise. + */ + +ISC_LANG_ENDDECLS |