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/*
* First, the stuff that ends up in the outside-world include file
= typedef off_t regoff_t;
= typedef struct {
= int re_magic;
= size_t re_nsub; // number of parenthesized subexpressions
= const char *re_endp; // end pointer for REG_PEND
= struct re_guts *re_g; // none of your business :-)
= } regex_t;
= typedef struct {
= regoff_t rm_so; // start of match
= regoff_t rm_eo; // end of match
= } regmatch_t;
*/
/*
* internals of regex_t
*/
#define MAGIC1 ((('r'^0200)<<8) | 'e')
/*
* The internal representation is a *strip*, a sequence of
* operators ending with an endmarker. (Some terminology etc. is a
* historical relic of earlier versions which used multiple strips.)
* Certain oddities in the representation are there to permit running
* the machinery backwards; in particular, any deviation from sequential
* flow must be marked at both its source and its destination. Some
* fine points:
*
* - OPLUS_ and O_PLUS are *inside* the loop they create.
* - OQUEST_ and O_QUEST are *outside* the bypass they create.
* - OCH_ and O_CH are *outside* the multi-way branch they create, while
* OOR1 and OOR2 are respectively the end and the beginning of one of
* the branches. Note that there is an implicit OOR2 following OCH_
* and an implicit OOR1 preceding O_CH.
*
* In state representations, an operator's bit is on to signify a state
* immediately *preceding* "execution" of that operator.
*/
typedef long sop; /* strip operator */
typedef long sopno;
#define OPRMASK 0x7c000000
#define OPDMASK 0x03ffffff
#define OPSHIFT (26)
#define OP(n) ((n)&OPRMASK)
#define OPND(n) ((n)&OPDMASK)
#define SOP(op, opnd) ((op)|(opnd))
/* operators meaning operand */
/* (back, fwd are offsets) */
#define OEND (1<<OPSHIFT) /* endmarker - */
#define OCHAR (2<<OPSHIFT) /* character unsigned char */
#define OBOL (3<<OPSHIFT) /* left anchor - */
#define OEOL (4<<OPSHIFT) /* right anchor - */
#define OANY (5<<OPSHIFT) /* . - */
#define OANYOF (6<<OPSHIFT) /* [...] set number */
#define OBACK_ (7<<OPSHIFT) /* begin \d paren number */
#define O_BACK (8<<OPSHIFT) /* end \d paren number */
#define OPLUS_ (9<<OPSHIFT) /* + prefix fwd to suffix */
#define O_PLUS (10<<OPSHIFT) /* + suffix back to prefix */
#define OQUEST_ (11<<OPSHIFT) /* ? prefix fwd to suffix */
#define O_QUEST (12<<OPSHIFT) /* ? suffix back to prefix */
#define OLPAREN (13<<OPSHIFT) /* ( fwd to ) */
#define ORPAREN (14<<OPSHIFT) /* ) back to ( */
#define OCH_ (15<<OPSHIFT) /* begin choice fwd to OOR2 */
#define OOR1 (16<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
#define OOR2 (17<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
#define O_CH (18<<OPSHIFT) /* end choice back to OOR1 */
#define OBOW (19<<OPSHIFT) /* begin word - */
#define OEOW (20<<OPSHIFT) /* end word - */
/*
* Structure for [] character-set representation. Character sets are
* done as bit vectors, grouped 8 to a byte vector for compactness.
* The individual set therefore has both a pointer to the byte vector
* and a mask to pick out the relevant bit of each byte. A hash code
* simplifies testing whether two sets could be identical.
*
* This will get trickier for multicharacter collating elements. As
* preliminary hooks for dealing with such things, we also carry along
* a string of multi-character elements, and decide the size of the
* vectors at run time.
*/
typedef struct {
uch *ptr; /* -> uch [csetsize] */
uch mask; /* bit within array */
uch hash; /* hash code */
size_t smultis;
char *multis; /* -> char[smulti] ab\0cd\0ef\0\0 */
} cset;
/* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
#define CHadd(cs, c) ((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
#define CHsub(cs, c) ((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
#define CHIN(cs, c) ((cs)->ptr[(uch)(c)] & (cs)->mask)
#define MCadd(p, cs, cp) mcadd(p, cs, cp) /* regcomp() internal fns */
#define MCsub(p, cs, cp) mcsub(p, cs, cp)
#define MCin(p, cs, cp) mcin(p, cs, cp)
/* stuff for character categories */
typedef unsigned char cat_t;
/*
* main compiled-expression structure
*/
struct re_guts {
int magic;
# define MAGIC2 ((('R'^0200)<<8)|'E')
sop *strip; /* malloced area for strip */
int csetsize; /* number of bits in a cset vector */
int ncsets; /* number of csets in use */
cset *sets; /* -> cset [ncsets] */
uch *setbits; /* -> uch[csetsize][ncsets/CHAR_BIT] */
int cflags; /* copy of regcomp() cflags argument */
sopno nstates; /* = number of sops */
sopno firststate; /* the initial OEND (normally 0) */
sopno laststate; /* the final OEND */
int iflags; /* internal flags */
# define USEBOL 01 /* used ^ */
# define USEEOL 02 /* used $ */
# define BAD 04 /* something wrong */
int nbol; /* number of ^ used */
int neol; /* number of $ used */
int ncategories; /* how many character categories */
cat_t *categories; /* ->catspace[-CHAR_MIN] */
char *must; /* match must contain this string */
int mlen; /* length of must */
size_t nsub; /* copy of re_nsub */
int backrefs; /* does it use back references? */
sopno nplus; /* how deep does it nest +s? */
/* catspace must be last */
cat_t catspace[1]; /* actually [NC] */
};
/* misc utilities */
#define OUT (CHAR_MAX+1) /* a non-character value */
#define ISWORD(c) (isalnum(c) || (c) == '_')