1 /* 2 * First, the stuff that ends up in the outside-world include file 3 = typedef off_t regoff_t; 4 = typedef struct { 5 = int re_magic; 6 = size_t re_nsub; // number of parenthesized subexpressions 7 = const char *re_endp; // end pointer for REG_PEND 8 = struct re_guts *re_g; // none of your business :-) 9 = } regex_t; 10 = typedef struct { 11 = regoff_t rm_so; // start of match 12 = regoff_t rm_eo; // end of match 13 = } regmatch_t; 14 */ 15 /* 16 * internals of regex_t 17 */ 18 #define MAGIC1 ((('r'^0200)<<8) | 'e') 19 20 /* 21 * The internal representation is a *strip*, a sequence of 22 * operators ending with an endmarker. (Some terminology etc. is a 23 * historical relic of earlier versions which used multiple strips.) 24 * Certain oddities in the representation are there to permit running 25 * the machinery backwards; in particular, any deviation from sequential 26 * flow must be marked at both its source and its destination. Some 27 * fine points: 28 * 29 * - OPLUS_ and O_PLUS are *inside* the loop they create. 30 * - OQUEST_ and O_QUEST are *outside* the bypass they create. 31 * - OCH_ and O_CH are *outside* the multi-way branch they create, while 32 * OOR1 and OOR2 are respectively the end and the beginning of one of 33 * the branches. Note that there is an implicit OOR2 following OCH_ 34 * and an implicit OOR1 preceding O_CH. 35 * 36 * In state representations, an operator's bit is on to signify a state 37 * immediately *preceding* "execution" of that operator. 38 */ 39 typedef long sop; /* strip operator */ 40 typedef long sopno; 41 #define OPRMASK 0x7c000000 42 #define OPDMASK 0x03ffffff 43 #define OPSHIFT (26) 44 #define OP(n) ((n)&OPRMASK) 45 #define OPND(n) ((n)&OPDMASK) 46 #define SOP(op, opnd) ((op)|(opnd)) 47 /* operators meaning operand */ 48 /* (back, fwd are offsets) */ 49 #define OEND (1<<OPSHIFT) /* endmarker - */ 50 #define OCHAR (2<<OPSHIFT) /* character unsigned char */ 51 #define OBOL (3<<OPSHIFT) /* left anchor - */ 52 #define OEOL (4<<OPSHIFT) /* right anchor - */ 53 #define OANY (5<<OPSHIFT) /* . - */ 54 #define OANYOF (6<<OPSHIFT) /* [...] set number */ 55 #define OBACK_ (7<<OPSHIFT) /* begin \d paren number */ 56 #define O_BACK (8<<OPSHIFT) /* end \d paren number */ 57 #define OPLUS_ (9<<OPSHIFT) /* + prefix fwd to suffix */ 58 #define O_PLUS (10<<OPSHIFT) /* + suffix back to prefix */ 59 #define OQUEST_ (11<<OPSHIFT) /* ? prefix fwd to suffix */ 60 #define O_QUEST (12<<OPSHIFT) /* ? suffix back to prefix */ 61 #define OLPAREN (13<<OPSHIFT) /* ( fwd to ) */ 62 #define ORPAREN (14<<OPSHIFT) /* ) back to ( */ 63 #define OCH_ (15<<OPSHIFT) /* begin choice fwd to OOR2 */ 64 #define OOR1 (16<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */ 65 #define OOR2 (17<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */ 66 #define O_CH (18<<OPSHIFT) /* end choice back to OOR1 */ 67 #define OBOW (19<<OPSHIFT) /* begin word - */ 68 #define OEOW (20<<OPSHIFT) /* end word - */ 69 70 /* 71 * Structure for [] character-set representation. Character sets are 72 * done as bit vectors, grouped 8 to a byte vector for compactness. 73 * The individual set therefore has both a pointer to the byte vector 74 * and a mask to pick out the relevant bit of each byte. A hash code 75 * simplifies testing whether two sets could be identical. 76 * 77 * This will get trickier for multicharacter collating elements. As 78 * preliminary hooks for dealing with such things, we also carry along 79 * a string of multi-character elements, and decide the size of the 80 * vectors at run time. 81 */ 82 typedef struct { 83 uch *ptr; /* -> uch [csetsize] */ 84 uch mask; /* bit within array */ 85 uch hash; /* hash code */ 86 size_t smultis; 87 char *multis; /* -> char[smulti] ab\0cd\0ef\0\0 */ 88 } cset; 89 /* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */ 90 #define CHadd(cs, c) ((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c)) 91 #define CHsub(cs, c) ((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c)) 92 #define CHIN(cs, c) ((cs)->ptr[(uch)(c)] & (cs)->mask) 93 #define MCadd(p, cs, cp) mcadd(p, cs, cp) /* regcomp() internal fns */ 94 #define MCsub(p, cs, cp) mcsub(p, cs, cp) 95 #define MCin(p, cs, cp) mcin(p, cs, cp) 96 97 /* stuff for character categories */ 98 typedef unsigned char cat_t; 99 100 /* 101 * main compiled-expression structure 102 */ 103 struct re_guts { 104 int magic; 105 # define MAGIC2 ((('R'^0200)<<8)|'E') 106 sop *strip; /* malloced area for strip */ 107 int csetsize; /* number of bits in a cset vector */ 108 int ncsets; /* number of csets in use */ 109 cset *sets; /* -> cset [ncsets] */ 110 uch *setbits; /* -> uch[csetsize][ncsets/CHAR_BIT] */ 111 int cflags; /* copy of regcomp() cflags argument */ 112 sopno nstates; /* = number of sops */ 113 sopno firststate; /* the initial OEND (normally 0) */ 114 sopno laststate; /* the final OEND */ 115 int iflags; /* internal flags */ 116 # define USEBOL 01 /* used ^ */ 117 # define USEEOL 02 /* used $ */ 118 # define BAD 04 /* something wrong */ 119 int nbol; /* number of ^ used */ 120 int neol; /* number of $ used */ 121 int ncategories; /* how many character categories */ 122 cat_t *categories; /* ->catspace[-CHAR_MIN] */ 123 char *must; /* match must contain this string */ 124 int mlen; /* length of must */ 125 size_t nsub; /* copy of re_nsub */ 126 int backrefs; /* does it use back references? */ 127 sopno nplus; /* how deep does it nest +s? */ 128 /* catspace must be last */ 129 cat_t catspace[1]; /* actually [NC] */ 130 }; 131 132 /* misc utilities */ 133 #define OUT (CHAR_MAX+1) /* a non-character value */ 134 #define ISWORD(c) (isalnum(c) || (c) == '_') 135