cpython/Modules/pcre-internal.h

/*************************************************
*      Perl-Compatible Regular Expressions       *
*************************************************/


#define PCRE_VERSION       "0.95 23-Sep-1997"


/* This is a library of functions to support regular expressions whose syntax
and semantics are as close as possible to those of the Perl 5 language. See
the file Tech.Notes for some information on the internals.

Written by: Philip Hazel <ph10@cam.ac.uk>

           Copyright (c) 1997 University of Cambridge

-----------------------------------------------------------------------------
Permission is granted to anyone to use this software for any purpose on any
computer system, and to redistribute it freely, subject to the following
restrictions:

1. This software 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.

2. The origin of this software must not be misrepresented, either by
   explicit claim or by omission.

3. Altered versions must be plainly marked as such, and must not be
   misrepresented as being the original software.
-----------------------------------------------------------------------------
*/

/* This header contains definitions that are shared between the different
modules, but which are not relevant to the outside. */

/* Standard C headers plus the external interface definition */

#include <ctype.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pcre.h"

/* Private options flags start at the most significant end of the byte. The
public options defined in pcre.h start at the least significant end. Make sure
they don't overlap! */

#define PCRE_FIRSTSET  0x80          /* first_char is set */
#define PCRE_STARTLINE 0x40          /* start after \n for multiline */

/* Options for the "extra" block produced by pcre_study(). */

#define PCRE_STUDY_CASELESS 0x01     /* study was caseless */
#define PCRE_STUDY_MAPPED   0x20     /* a map of starting chars exists */

/* Masks for identifying the public options: all permitted at compile time,
only some permitted at run or study time. */

#ifdef FOR_PYTHON
#define PUBLIC_OPTIONS \
  (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE|PCRE_DOTALL)
#else
#define PUBLIC_OPTIONS \
  (PCRE_CASELESS|PCRE_EXTENDED|PCRE_ANCHORED|PCRE_MULTILINE)
#endif
#define PUBLIC_EXEC_OPTIONS (PCRE_CASELESS|PCRE_ANCHORED|PCRE_MULTILINE)
#define PUBLIC_STUDY_OPTIONS (PCRE_CASELESS)

/* Magic number to provide a small check against being handed junk. */

#define MAGIC_NUMBER  0x50435245   /* 'PCRE' */

/* Miscellaneous definitions */

typedef int BOOL;

#define FALSE   0
#define TRUE    1

/* Flags for character classes - see also class_ops table below. */

#define CLASS_DIGITS         0x01
#define CLASS_NOT_DIGITS     0x02
#define CLASS_WHITESPACE     0x04
#define CLASS_NOT_WHITESPACE 0x08
#define CLASS_WORD           0x10
#define CLASS_NOT_WORD       0x20

/* These are escaped items that aren't just an encoding of a particular data
value such as \n. They must have non-zero values, as check_escape() returns
their negation. Also, they must appear in the same order as in the opcode
definitions below, up to ESC_Z. The final one must be ESC_REF as subsequent
values are used for \1, \2, \3, etc. There is a test in the code for an escape
greater than ESC_b and less than ESC_Z to detect the types that may be
repeated. If any new escapes are put in-between that don't consume a character,
that code will have to change. */

enum { ESC_A = 1, ESC_B, ESC_b, ESC_D, ESC_d, ESC_S, ESC_s, ESC_W, ESC_w,
       ESC_Z, ESC_REF };

/* Opcode table: OP_BRA must be last, as all values >= it are used for brackets
that extract substrings. Starting from 1 (i.e. after OP_END), the values up to
OP_EOL must correspond in order to the list of escapes immediately above. */

enum {
  OP_END,            /* End of pattern */

  /* Values corresponding to backslashed metacharacters */

  OP_SOD,            /* Start of data: \A */
  OP_NOT_WORD_BOUNDARY,  /* \W */
  OP_WORD_BOUNDARY,      /* \w */
  OP_NOT_DIGIT,          /* \D */
  OP_DIGIT,              /* \d */
  OP_NOT_WHITESPACE,     /* \S */
  OP_WHITESPACE,         /* \s */
  OP_NOT_WORDCHAR,       /* \W */
  OP_WORDCHAR,           /* \w */
  OP_EOD,            /* End of data: or \Z. This must always be the last
                        of the backslashed meta values. */

  OP_CIRC,           /* Start of line - varies with multiline switch */
  OP_DOLL,           /* End of line - varies with multiline switch */
  OP_ANY,            /* Match any character */
  OP_CHARS,          /* Match string of characters */

  OP_STAR,           /* The maximizing and minimizing versions of */
  OP_MINSTAR,        /* all these opcodes must come in pairs, with */
  OP_PLUS,           /* the minimizing one second. */
  OP_MINPLUS,        /* This first set applies to single characters */
  OP_QUERY,
  OP_MINQUERY,
  OP_UPTO,           /* From 0 to n matches. */
  OP_MINUPTO,
  OP_EXACT,          /* Exactly n matches. */

  OP_TYPESTAR,       /* The maximizing and minimizing versions of */
  OP_TYPEMINSTAR,    /* all these opcodes must come in pairs, with */
  OP_TYPEPLUS,       /* the minimizing one second. These codes must */
  OP_TYPEMINPLUS,    /* be in exactly the same order as those above. */
  OP_TYPEQUERY,      /* This set applies to character types such as \d */
  OP_TYPEMINQUERY,
  OP_TYPEUPTO,
  OP_TYPEMINUPTO,
  OP_TYPEEXACT,

  OP_CRSTAR,         /* The maximizing and minimizing versions of */
  OP_CRMINSTAR,      /* all these opcodes must come in pairs, with */
  OP_CRPLUS,         /* the minimizing one second. These codes must */
  OP_CRMINPLUS,      /* be in exactly the same order as those above. */
  OP_CRQUERY,        /* These are for character classes and back refs */
  OP_CRMINQUERY,
  OP_CRRANGE,        /* These are different to the two seta above. */
  OP_CRMINRANGE,

  OP_CLASS,          /* Match a character class */
  OP_NEGCLASS,       /* Don't match a character class */
  OP_REF,            /* Match a back reference */

  OP_ALT,            /* Start of alternation */
  OP_KET,            /* End of group that doesn't have an unbounded repeat */
  OP_KETRMAX,        /* These two must remain together and in this */
  OP_KETRMIN,        /* order. They are for groups the repeat for ever. */

  OP_ASSERT,
  OP_ASSERT_NOT,

  OP_BRAZERO,        /* These two must remain together and in this */
  OP_BRAMINZERO,     /* order. */

  OP_BRA             /* This and greater values are used for brackets that
                        extract substrings. */
};

/* The highest extraction number. This is limited by the number of opcodes
left after OP_BRA, i.e. 255 - OP_BRA. We actually set it somewhat lower. */

#define EXTRACT_MAX  99

/* All character handling must be done as unsigned characters. Otherwise there
are problems with top-bit-set characters and functions such as isspace().
However, we leave the interface to the outside world as char *, because that
should make things easier for callers. We define a short type for unsigned char
to save lots of typing. I tried "uchar", but it causes problems on Digital
Unix, where it is defined in sys/types, so use "uschar" instead. */

typedef unsigned char uschar;

/* The real format of the start of the pcre block; the actual code vector
runs on as long as necessary after the end. */

typedef struct real_pcre {
  unsigned int  magic_number;
  unsigned char options;
  unsigned char top_bracket;
  unsigned char first_char;
  unsigned char code[1];
} real_pcre;

/* The real format of the extra block returned by pcre_study(). */

typedef struct real_pcre_extra {
  unsigned char options;
  unsigned char start_bits[32];
} real_pcre_extra;

/* Global tables from pcre-chartables.c */

extern uschar pcre_lcc[];
extern uschar pcre_ucc[];
extern uschar pcre_ctypes[];

/* Bit definitions for entries in pcre_ctypes[]. */

#define ctype_space   0x01
#define ctype_digit   0x02
#define ctype_xdigit  0x04
#define ctype_word    0x08   /* alphameric or '_' */
#ifdef FOR_PYTHON
#define ctype_odigit  0x10   /* Octal digits */
#endif
#define ctype_meta    0x80   /* regexp meta char or zero (end pattern) */

/* End of pcre-internal.h */