1 /*
2 * First, the stuff that ends up in the outside-world include file
3 = #ifdef WIN32
4 = #define API_EXPORT(type) __declspec(dllexport) type __stdcall
5 = #else
6 = #define API_EXPORT(type) type
7 = #endif
8 =
9 = typedef off_t regoff_t;
10 = typedef struct {
11 = int re_magic;
12 = size_t re_nsub; // number of parenthesized subexpressions
13 = const unsigned char *re_endp; // end pointer for REG_PEND
14 = struct re_guts *re_g; // none of your business :-)
15 = } regex_t;
16 = typedef struct {
17 = regoff_t rm_so; // start of match
18 = regoff_t rm_eo; // end of match
19 = } regmatch_t;
20 */
21 /*
22 * internals of regex_t
23 */
24 #define MAGIC1 ((('r'^0200)<<8) | 'e')
25
26 /*
27 * The internal representation is a *strip*, a sequence of
28 * operators ending with an endmarker. (Some terminology etc. is a
29 * historical relic of earlier versions which used multiple strips.)
30 * Certain oddities in the representation are there to permit running
31 * the machinery backwards; in particular, any deviation from sequential
32 * flow must be marked at both its source and its destination. Some
33 * fine points:
34 *
35 * - OPLUS_ and O_PLUS are *inside* the loop they create.
36 * - OQUEST_ and O_QUEST are *outside* the bypass they create.
37 * - OCH_ and O_CH are *outside* the multi-way branch they create, while
38 * OOR1 and OOR2 are respectively the end and the beginning of one of
39 * the branches. Note that there is an implicit OOR2 following OCH_
40 * and an implicit OOR1 preceding O_CH.
41 *
42 * In state representations, an operator's bit is on to signify a state
43 * immediately *preceding* "execution" of that operator.
44 */
45 typedef long sop; /* strip operator */
46 typedef long sopno;
47 #define OPRMASK 0x7c000000
48 #define OPDMASK 0x03ffffff
49 #define OPSHIFT (26)
50 #define OP(n) ((n)&OPRMASK)
51 #define OPND(n) ((n)&OPDMASK)
52 #define SOP(op, opnd) ((op)|(opnd))
53 /* operators meaning operand */
54 /* (back, fwd are offsets) */
55 #define OEND (1<<OPSHIFT) /* endmarker - */
56 #define OCHAR (2<<OPSHIFT) /* character unsigned char */
57 #define OBOL (3<<OPSHIFT) /* left anchor - */
58 #define OEOL (4<<OPSHIFT) /* right anchor - */
59 #define OANY (5<<OPSHIFT) /* . - */
60 #define OANYOF (6<<OPSHIFT) /* [...] set number */
61 #define OBACK_ (7<<OPSHIFT) /* begin \d paren number */
62 #define O_BACK (8<<OPSHIFT) /* end \d paren number */
63 #define OPLUS_ (9<<OPSHIFT) /* + prefix fwd to suffix */
64 #define O_PLUS (10<<OPSHIFT) /* + suffix back to prefix */
65 #define OQUEST_ (11<<OPSHIFT) /* ? prefix fwd to suffix */
66 #define O_QUEST (12<<OPSHIFT) /* ? suffix back to prefix */
67 #define OLPAREN (13<<OPSHIFT) /* ( fwd to ) */
68 #define ORPAREN (14<<OPSHIFT) /* ) back to ( */
69 #define OCH_ (15<<OPSHIFT) /* begin choice fwd to OOR2 */
70 #define OOR1 (16<<OPSHIFT) /* | pt. 1 back to OOR1 or OCH_ */
71 #define OOR2 (17<<OPSHIFT) /* | pt. 2 fwd to OOR2 or O_CH */
72 #define O_CH (18<<OPSHIFT) /* end choice back to OOR1 */
73 #define OBOW (19<<OPSHIFT) /* begin word - */
74 #define OEOW (20<<OPSHIFT) /* end word - */
75
76 /*
77 * Structure for [] character-set representation. Character sets are
78 * done as bit vectors, grouped 8 to a byte vector for compactness.
79 * The individual set therefore has both a pointer to the byte vector
80 * and a mask to pick out the relevant bit of each byte. A hash code
81 * simplifies testing whether two sets could be identical.
82 *
83 * This will get trickier for multicharacter collating elements. As
84 * preliminary hooks for dealing with such things, we also carry along
85 * a string of multi-character elements, and decide the size of the
86 * vectors at run time.
87 */
88 typedef struct {
89 uch *ptr; /* -> uch [csetsize] */
90 uch mask; /* bit within array */
91 uch hash; /* hash code */
92 size_t smultis;
93 unsigned char *multis; /* -> char[smulti] ab\0cd\0ef\0\0 */
94 } cset;
95 /* note that CHadd and CHsub are unsafe, and CHIN doesn't yield 0/1 */
96 #define CHadd(cs, c) ((cs)->ptr[(uch)(c)] |= (cs)->mask, (cs)->hash += (c))
97 #define CHsub(cs, c) ((cs)->ptr[(uch)(c)] &= ~(cs)->mask, (cs)->hash -= (c))
98 #define CHIN(cs, c) ((cs)->ptr[(uch)(c)] & (cs)->mask)
99 #define MCadd(p, cs, cp) mcadd(p, cs, cp) /* regcomp() internal fns */
100 #define MCsub(p, cs, cp) mcsub(p, cs, cp)
101 #define MCin(p, cs, cp) mcin(p, cs, cp)
102
103 /* stuff for character categories */
104 typedef unsigned char cat_t;
105
106 /*
107 * main compiled-expression structure
108 */
109 struct re_guts {
110 int magic;
111 # define MAGIC2 ((('R'^0200)<<8)|'E')
112 sop *strip; /* malloced area for strip */
113 int csetsize; /* number of bits in a cset vector */
114 int ncsets; /* number of csets in use */
115 cset *sets; /* -> cset [ncsets] */
116 uch *setbits; /* -> uch[csetsize][ncsets/CHAR_BIT] */
117 int cflags; /* copy of regcomp() cflags argument */
118 sopno nstates; /* = number of sops */
119 sopno firststate; /* the initial OEND (normally 0) */
120 sopno laststate; /* the final OEND */
121 int iflags; /* internal flags */
122 # define USEBOL 01 /* used ^ */
123 # define USEEOL 02 /* used $ */
124 # define BAD 04 /* something wrong */
125 int nbol; /* number of ^ used */
126 int neol; /* number of $ used */
127 int ncategories; /* how many character categories */
128 cat_t *categories; /* ->catspace[-UCHAR_MIN] */
129 unsigned char *must; /* match must contain this string */
130 int mlen; /* length of must */
131 size_t nsub; /* copy of re_nsub */
132 int backrefs; /* does it use back references? */
133 sopno nplus; /* how deep does it nest +s? */
134 /* catspace must be last */
135 cat_t catspace[1]; /* actually [NC] */
136 };
137
138 /* misc utilities */
139 #define OUT (UCHAR_MAX+1) /* a non-character value */
140 #define ISWORD(c) (isalnum(c) || (c) == '_')