contrib/bind-9.5.2/lib/isc/include/isc/lex.h

   1 /*
   2  * Copyright (C) 2004, 2005, 2007, 2008  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1998-2002  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: lex.h,v 1.35.128.2 2008/05/30 23:46:31 tbox Exp $ */
  19
  20 #ifndef ISC_LEX_H
  21 #define ISC_LEX_H 1
  22
  23 /*****
  24  ***** Module Info
  25  *****/
  26
  27 /*! \file isc/lex.h
  28  * \brief The "lex" module provides a lightweight tokenizer.  It can operate
  29  * on files or buffers, and can handle "include".  It is designed for
  30  * parsing of DNS master files and the BIND configuration file, but
  31  * should be general enough to tokenize other things, e.g. HTTP.
  32  *
  33  * \li MP:
  34  *      No synchronization is provided.  Clients must ensure exclusive
  35  *      access.
  36  *
  37  * \li Reliability:
  38  *      No anticipated impact.
  39  *
  40  * \li Resources:
  41  *      TBS
  42  *
  43  * \li Security:
  44  *      No anticipated impact.
  45  *
  46  * \li Standards:
  47  *      None.
  48  */
  49
  50 /***
  51  *** Imports
  52  ***/
  53
  54 #include <stdio.h>
  55
  56 #include <isc/lang.h>
  57 #include <isc/region.h>
  58 #include <isc/types.h>
  59
  60 ISC_LANG_BEGINDECLS
  61
  62 /***
  63  *** Options
  64  ***/
  65
  66 /*@{*/
  67 /*!
  68  * Various options for isc_lex_gettoken().
  69  */
  70
  71 #define ISC_LEXOPT_EOL                  0x01    /*%< Want end-of-line token. */
  72 #define ISC_LEXOPT_EOF                  0x02    /*%< Want end-of-file token. */
  73 #define ISC_LEXOPT_INITIALWS            0x04    /*%< Want initial whitespace. */
  74 #define ISC_LEXOPT_NUMBER               0x08    /*%< Recognize numbers. */
  75 #define ISC_LEXOPT_QSTRING              0x10    /*%< Recognize qstrings. */
  76 /*@}*/
  77
  78 /*@{*/
  79 /*!
  80  * The ISC_LEXOPT_DNSMULTILINE option handles the processing of '(' and ')' in
  81  * the DNS master file format.  If this option is set, then the
  82  * ISC_LEXOPT_INITIALWS and ISC_LEXOPT_EOL options will be ignored when
  83  * the paren count is > 0.  To use this option, '(' and ')' must be special
  84  * characters.
  85  */
  86 #define ISC_LEXOPT_DNSMULTILINE         0x20    /*%< Handle '(' and ')'. */
  87 #define ISC_LEXOPT_NOMORE               0x40    /*%< Want "no more" token. */
  88
  89 #define ISC_LEXOPT_CNUMBER              0x80    /*%< Recognize octal and hex. */
  90 #define ISC_LEXOPT_ESCAPE               0x100   /*%< Recognize escapes. */
  91 #define ISC_LEXOPT_QSTRINGMULTILINE     0x200   /*%< Allow multiline "" strings */
  92 #define ISC_LEXOPT_OCTAL                0x400   /*%< Expect a octal number. */
  93 /*@}*/
  94 /*@{*/
  95 /*!
  96  * Various commenting styles, which may be changed at any time with
  97  * isc_lex_setcomments().
  98  */
  99
 100 #define ISC_LEXCOMMENT_C                0x01
 101 #define ISC_LEXCOMMENT_CPLUSPLUS        0x02
 102 #define ISC_LEXCOMMENT_SHELL            0x04
 103 #define ISC_LEXCOMMENT_DNSMASTERFILE    0x08
 104 /*@}*/
 105
 106 /***
 107  *** Types
 108  ***/
 109
 110 /*! Lex */
 111
 112 typedef char isc_lexspecials_t[256];
 113
 114 /* Tokens */
 115
 116 typedef enum {
 117         isc_tokentype_unknown = 0,
 118         isc_tokentype_string = 1,
 119         isc_tokentype_number = 2,
 120         isc_tokentype_qstring = 3,
 121         isc_tokentype_eol = 4,
 122         isc_tokentype_eof = 5,
 123         isc_tokentype_initialws = 6,
 124         isc_tokentype_special = 7,
 125         isc_tokentype_nomore = 8
 126 } isc_tokentype_t;
 127
 128 typedef union {
 129         char                            as_char;
 130         unsigned long                   as_ulong;
 131         isc_region_t                    as_region;
 132         isc_textregion_t                as_textregion;
 133         void *                          as_pointer;
 134 } isc_tokenvalue_t;
 135
 136 typedef struct isc_token {
 137         isc_tokentype_t                 type;
 138         isc_tokenvalue_t                value;
 139 } isc_token_t;
 140
 141 /***
 142  *** Functions
 143  ***/
 144
 145 isc_result_t
 146 isc_lex_create(isc_mem_t *mctx, size_t max_token, isc_lex_t **lexp);
 147 /*%<
 148  * Create a lexer.
 149  *
 150  * 'max_token' is a hint of the number of bytes in the largest token.
 151  *
 152  * Requires:
 153  *\li   '*lexp' is a valid lexer.
 154  *
 155  *\li   max_token > 0.
 156  *
 157  * Ensures:
 158  *\li   On success, *lexp is attached to the newly created lexer.
 159  *
 160  * Returns:
 161  *\li   #ISC_R_SUCCESS
 162  *\li   #ISC_R_NOMEMORY
 163  */
 164
 165 void
 166 isc_lex_destroy(isc_lex_t **lexp);
 167 /*%<
 168  * Destroy the lexer.
 169  *
 170  * Requires:
 171  *\li   '*lexp' is a valid lexer.
 172  *
 173  * Ensures:
 174  *\li   *lexp == NULL
 175  */
 176
 177 unsigned int
 178 isc_lex_getcomments(isc_lex_t *lex);
 179 /*%<
 180  * Return the current lexer commenting styles.
 181  *
 182  * Requires:
 183  *\li   'lex' is a valid lexer.
 184  *
 185  * Returns:
 186  *\li   The commenting sytles which are currently allowed.
 187  */
 188
 189 void
 190 isc_lex_setcomments(isc_lex_t *lex, unsigned int comments);
 191 /*%<
 192  * Set allowed lexer commenting styles.
 193  *
 194  * Requires:
 195  *\li   'lex' is a valid lexer.
 196  *
 197  *\li   'comments' has meaningful values.
 198  */
 199
 200 void
 201 isc_lex_getspecials(isc_lex_t *lex, isc_lexspecials_t specials);
 202 /*%<
 203  * Put the current list of specials into 'specials'.
 204  *
 205  * Requires:
 206  *\li   'lex' is a valid lexer.
 207  */
 208
 209 void
 210 isc_lex_setspecials(isc_lex_t *lex, isc_lexspecials_t specials);
 211 /*!<
 212  * The characters in 'specials' are returned as tokens.  Along with
 213  * whitespace, they delimit strings and numbers.
 214  *
 215  * Note:
 216  *\li   Comment processing takes precedence over special character
 217  *      recognition.
 218  *
 219  * Requires:
 220  *\li   'lex' is a valid lexer.
 221  */
 222
 223 isc_result_t
 224 isc_lex_openfile(isc_lex_t *lex, const char *filename);
 225 /*%<
 226  * Open 'filename' and make it the current input source for 'lex'.
 227  *
 228  * Requires:
 229  *\li   'lex' is a valid lexer.
 230  *
 231  *\li   filename is a valid C string.
 232  *
 233  * Returns:
 234  *\li   #ISC_R_SUCCESS
 235  *\li   #ISC_R_NOMEMORY                 Out of memory
 236  *\li   #ISC_R_NOTFOUND                 File not found
 237  *\li   #ISC_R_NOPERM                   No permission to open file
 238  *\li   #ISC_R_FAILURE                  Couldn't open file, not sure why
 239  *\li   #ISC_R_UNEXPECTED
 240  */
 241
 242 isc_result_t
 243 isc_lex_openstream(isc_lex_t *lex, FILE *stream);
 244 /*%<
 245  * Make 'stream' the current input source for 'lex'.
 246  *
 247  * Requires:
 248  *\li   'lex' is a valid lexer.
 249  *
 250  *\li   'stream' is a valid C stream.
 251  *
 252  * Returns:
 253  *\li   #ISC_R_SUCCESS
 254  *\li   #ISC_R_NOMEMORY                 Out of memory
 255  */
 256
 257 isc_result_t
 258 isc_lex_openbuffer(isc_lex_t *lex, isc_buffer_t *buffer);
 259 /*%<
 260  * Make 'buffer' the current input source for 'lex'.
 261  *
 262  * Requires:
 263  *\li   'lex' is a valid lexer.
 264  *
 265  *\li   'buffer' is a valid buffer.
 266  *
 267  * Returns:
 268  *\li   #ISC_R_SUCCESS
 269  *\li   #ISC_R_NOMEMORY                 Out of memory
 270  */
 271
 272 isc_result_t
 273 isc_lex_close(isc_lex_t *lex);
 274 /*%<
 275  * Close the most recently opened object (i.e. file or buffer).
 276  *
 277  * Returns:
 278  *\li   #ISC_R_SUCCESS
 279  *\li   #ISC_R_NOMORE                   No more input sources
 280  */
 281
 282 isc_result_t
 283 isc_lex_gettoken(isc_lex_t *lex, unsigned int options, isc_token_t *tokenp);
 284 /*%<
 285  * Get the next token.
 286  *
 287  * Requires:
 288  *\li   'lex' is a valid lexer.
 289  *
 290  *\li   'lex' has an input source.
 291  *
 292  *\li   'options' contains valid options.
 293  *
 294  *\li   '*tokenp' is a valid pointer.
 295  *
 296  * Returns:
 297  *\li   #ISC_R_SUCCESS
 298  *\li   #ISC_R_UNEXPECTEDEND
 299  *\li   #ISC_R_NOMEMORY
 300  *
 301  *      These two results are returned only if their corresponding lexer
 302  *      options are not set.
 303  *
 304  *\li   #ISC_R_EOF                      End of input source
 305  *\li   #ISC_R_NOMORE                   No more input sources
 306  */
 307
 308 isc_result_t
 309 isc_lex_getmastertoken(isc_lex_t *lex, isc_token_t *token,
 310                        isc_tokentype_t expect, isc_boolean_t eol);
 311 /*%<
 312  * Get the next token from a DNS master file type stream.  This is a
 313  * convenience function that sets appropriate options and handles quoted
 314  * strings and end of line correctly for master files.  It also ungets
 315  * unexpected tokens.
 316  *
 317  * Requires:
 318  *\li   'lex' is a valid lexer.
 319  *
 320  *\li   'token' is a valid pointer
 321  *
 322  * Returns:
 323  *
 324  * \li  any return code from isc_lex_gettoken().
 325  */
 326
 327 isc_result_t
 328 isc_lex_getoctaltoken(isc_lex_t *lex, isc_token_t *token, isc_boolean_t eol);
 329 /*%<
 330  * Get the next token from a DNS master file type stream.  This is a
 331  * convenience function that sets appropriate options and handles end
 332  * of line correctly for master files.  It also ungets unexpected tokens.
 333  *
 334  * Requires:
 335  *\li   'lex' is a valid lexer.
 336  *
 337  *\li   'token' is a valid pointer
 338  *
 339  * Returns:
 340  *
 341  * \li  any return code from isc_lex_gettoken().
 342  */
 343
 344 void
 345 isc_lex_ungettoken(isc_lex_t *lex, isc_token_t *tokenp);
 346 /*%<
 347  * Unget the current token.
 348  *
 349  * Requires:
 350  *\li   'lex' is a valid lexer.
 351  *
 352  *\li   'lex' has an input source.
 353  *
 354  *\li   'tokenp' points to a valid token.
 355  *
 356  *\li   There is no ungotten token already.
 357  */
 358
 359 void
 360 isc_lex_getlasttokentext(isc_lex_t *lex, isc_token_t *tokenp, isc_region_t *r);
 361 /*%<
 362  * Returns a region containing the text of the last token returned.
 363  *
 364  * Requires:
 365  *\li   'lex' is a valid lexer.
 366  *
 367  *\li   'lex' has an input source.
 368  *
 369  *\li   'tokenp' points to a valid token.
 370  *
 371  *\li   A token has been gotten and not ungotten.
 372  */
 373
 374 char *
 375 isc_lex_getsourcename(isc_lex_t *lex);
 376 /*%<
 377  * Return the input source name.
 378  *
 379  * Requires:
 380  *\li   'lex' is a valid lexer.
 381  *
 382  * Returns:
 383  * \li  source name or NULL if no current source.
 384  *\li   result valid while current input source exists.
 385  */
 386
 387
 388 unsigned long
 389 isc_lex_getsourceline(isc_lex_t *lex);
 390 /*%<
 391  * Return the input source line number.
 392  *
 393  * Requires:
 394  *\li   'lex' is a valid lexer.
 395  *
 396  * Returns:
 397  *\li   Current line number or 0 if no current source.
 398  */
 399
 400 isc_result_t
 401 isc_lex_setsourcename(isc_lex_t *lex, const char *name);
 402 /*%<
 403  * Assigns a new name to the input source.
 404  *
 405  * Requires:
 406  *
 407  * \li  'lex' is a valid lexer.
 408  *
 409  * Returns:
 410  * \li  #ISC_R_SUCCESS
 411  * \li  #ISC_R_NOMEMORY
 412  * \li  #ISC_R_NOTFOUND - there are no sources.
 413  */
 414
 415 isc_boolean_t
 416 isc_lex_isfile(isc_lex_t *lex);
 417 /*%<
 418  * Return whether the current input source is a file.
 419  *
 420  * Requires:
 421  *\li   'lex' is a valid lexer.
 422  *
 423  * Returns:
 424  * \li  #ISC_TRUE if the current input is a file,
 425  *\li   #ISC_FALSE otherwise.
 426  */
 427
 428
 429 ISC_LANG_ENDDECLS
 430
 431 #endif /* ISC_LEX_H */