lib/Support/regex2.h

   1 /*-
   2  * This code is derived from OpenBSD's libc/regex, original license follows:
   3  *
   4  * Copyright (c) 1992, 1993, 1994 Henry Spencer.
   5  * Copyright (c) 1992, 1993, 1994
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * This code is derived from software contributed to Berkeley by
   9  * Henry Spencer.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions and the following disclaimer.
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in the
  18  *    documentation and/or other materials provided with the distribution.
  19  * 3. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  *
  35  *      @(#)regex2.h    8.4 (Berkeley) 3/20/94
  36  */
  37
  38 /*
  39  * internals of regex_t
  40  */
  41 #define MAGIC1  ((('r'^0200)<<8) | 'e')
  42
  43 /*
  44  * The internal representation is a *strip*, a sequence of
  45  * operators ending with an endmarker.  (Some terminology etc. is a
  46  * historical relic of earlier versions which used multiple strips.)
  47  * Certain oddities in the representation are there to permit running
  48  * the machinery backwards; in particular, any deviation from sequential
  49  * flow must be marked at both its source and its destination.  Some
  50  * fine points:
  51  *
  52  * - OPLUS_ and O_PLUS are *inside* the loop they create.
  53  * - OQUEST_ and O_QUEST are *outside* the bypass they create.
  54  * - OCH_ and O_CH are *outside* the multi-way branch they create, while
  55  *   OOR1 and OOR2 are respectively the end and the beginning of one of
  56  *   the branches.  Note that there is an implicit OOR2 following OCH_
  57  *   and an implicit OOR1 preceding O_CH.
  58  *
  59  * In state representations, an operator's bit is on to signify a state
  60  * immediately *preceding* "execution" of that operator.
  61  */
  62 typedef unsigned long sop;      /* strip operator */
  63 typedef long sopno;
  64 #define OPRMASK 0xf8000000LU
  65 #define OPDMASK 0x07ffffffLU
  66 #define OPSHIFT ((unsigned)27)
  67 #define OP(n)   ((n)&OPRMASK)
  68 #define OPND(n) ((n)&OPDMASK)
  69 #define SOP(op, opnd)   ((op)|(opnd))
  70 /* operators                       meaning      operand                 */
  71 /*                                              (back, fwd are offsets) */
  72 #define OEND    (1LU<<OPSHIFT)  /* endmarker    -                       */
  73 #define OCHAR   (2LU<<OPSHIFT)  /* character    unsigned char           */
  74 #define OBOL    (3LU<<OPSHIFT)  /* left anchor  -                       */
  75 #define OEOL    (4LU<<OPSHIFT)  /* right anchor -                       */
  76 #define OANY    (5LU<<OPSHIFT)  /* .            -                       */
  77 #define OANYOF  (6LU<<OPSHIFT)  /* [...]        set number              */
  78 #define OBACK_  (7LU<<OPSHIFT)  /* begin \d     paren number            */
  79 #define O_BACK  (8LU<<OPSHIFT)  /* end \d       paren number            */
  80 #define OPLUS_  (9LU<<OPSHIFT)  /* + prefix     fwd to suffix           */
  81 #define O_PLUS  (10LU<<OPSHIFT) /* + suffix     back to prefix          */
  82 #define OQUEST_ (11LU<<OPSHIFT) /* ? prefix     fwd to suffix           */
  83 #define O_QUEST (12LU<<OPSHIFT) /* ? suffix     back to prefix          */
  84 #define OLPAREN (13LU<<OPSHIFT) /* (            fwd to )                */
  85 #define ORPAREN (14LU<<OPSHIFT) /* )            back to (               */
  86 #define OCH_    (15LU<<OPSHIFT) /* begin choice fwd to OOR2             */
  87 #define OOR1    (16LU<<OPSHIFT) /* | pt. 1      back to OOR1 or OCH_    */
  88 #define OOR2    (17LU<<OPSHIFT) /* | pt. 2      fwd to OOR2 or O_CH     */
  89 #define O_CH    (18LU<<OPSHIFT) /* end choice   back to OOR1            */
  90 #define OBOW    (19LU<<OPSHIFT) /* begin word   -                       */
  91 #define OEOW    (20LU<<OPSHIFT) /* end word     -                       */
  92
  93 /*
  94  * Structure for [] character-set representation.  Character sets are
  95  * done as bit vectors, grouped 8 to a byte vector for compactness.
  96  * The individual set therefore has both a pointer to the byte vector
  97  * and a mask to pick out the relevant bit of each byte.  A hash code
  98  * simplifies testing whether two sets could be identical.
  99  *
 100  * This will get trickier for multicharacter collating elements.  As
 101  * preliminary hooks for dealing with such things, we also carry along
 102  * a string of multi-character elements, and decide the size of the
 103  * vectors at run time.
 104  */
 105 typedef struct {
 106         uch *ptr;               /* -> uch [csetsize] */
 107         uch mask;               /* bit within array */
 108         uch hash;               /* hash code */
 109         size_t smultis;
 110         char *multis;           /* -> char[smulti]  ab\0cd\0ef\0\0 */
 111 } cset;
 112 /* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
 113 #define CHadd(cs, c)    ((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
 114 #define CHsub(cs, c)    ((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
 115 #define CHIN(cs, c)     ((cs)->ptr[(uch)(c)] & (cs)->mask)
 116 #define MCadd(p, cs, cp)        mcadd(p, cs, cp)        /* llvm_regcomp() internal fns */
 117 #define MCsub(p, cs, cp)        mcsub(p, cs, cp)
 118 #define MCin(p, cs, cp) mcin(p, cs, cp)
 119
 120 /* stuff for character categories */
 121 typedef unsigned char cat_t;
 122
 123 /*
 124  * main compiled-expression structure
 125  */
 126 struct re_guts {
 127         int magic;
 128 #               define  MAGIC2  ((('R'^0200)<<8)|'E')
 129         sop *strip;             /* malloced area for strip */
 130         int csetsize;           /* number of bits in a cset vector */
 131         int ncsets;             /* number of csets in use */
 132         cset *sets;             /* -> cset [ncsets] */
 133         uch *setbits;           /* -> uch[csetsize][ncsets/CHAR_BIT] */
 134         int cflags;             /* copy of llvm_regcomp() cflags argument */
 135         sopno nstates;          /* = number of sops */
 136         sopno firststate;       /* the initial OEND (normally 0) */
 137         sopno laststate;        /* the final OEND */
 138         int iflags;             /* internal flags */
 139 #               define  USEBOL  01      /* used ^ */
 140 #               define  USEEOL  02      /* used $ */
 141 #               define  REGEX_BAD       04      /* something wrong */
 142         int nbol;               /* number of ^ used */
 143         int neol;               /* number of $ used */
 144         int ncategories;        /* how many character categories */
 145         cat_t *categories;      /* ->catspace[-CHAR_MIN] */
 146         char *must;             /* match must contain this string */
 147         int mlen;               /* length of must */
 148         size_t nsub;            /* copy of re_nsub */
 149         int backrefs;           /* does it use back references? */
 150         sopno nplus;            /* how deep does it nest +s? */
 151         /* catspace must be last */
 152         cat_t catspace[1];      /* actually [NC] */
 153 };
 154
 155 /* misc utilities */
 156 #define OUT     (CHAR_MAX+1)    /* a non-character value */
 157 #define ISWORD(c)       (isalnum(c&0xff) || (c) == '_')