1 /*    regcomp.h
2  *
3  *    Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4  *    2000, 2001, 2002, 2003, 2005 by Larry Wall and others
5  *
6  *    You may distribute under the terms of either the GNU General Public
7  *    License or the Artistic License, as specified in the README file.
8  *
9  */
10 
11 typedef OP OP_4tree;			/* Will be redefined later. */
12 
13 /*
14  * The "internal use only" fields in regexp.h are present to pass info from
15  * compile to execute that permits the execute phase to run lots faster on
16  * simple cases.  They are:
17  *
18  * regstart	sv that must begin a match; Nullch if none obvious
19  * reganch	is the match anchored (at beginning-of-line only)?
20  * regmust	string (pointer into program) that match must include, or NULL
21  *  [regmust changed to SV* for bminstr()--law]
22  * regmlen	length of regmust string
23  *  [regmlen not used currently]
24  *
25  * Regstart and reganch permit very fast decisions on suitable starting points
26  * for a match, cutting down the work a lot.  Regmust permits fast rejection
27  * of lines that cannot possibly match.  The regmust tests are costly enough
28  * that pregcomp() supplies a regmust only if the r.e. contains something
29  * potentially expensive (at present, the only such thing detected is * or +
30  * at the start of the r.e., which can involve a lot of backup).  Regmlen is
31  * supplied because the test in pregexec() needs it and pregcomp() is computing
32  * it anyway.
33  * [regmust is now supplied always.  The tests that use regmust have a
34  * heuristic that disables the test if it usually matches.]
35  *
36  * [In fact, we now use regmust in many cases to locate where the search
37  * starts in the string, so if regback is >= 0, the regmust search is never
38  * wasted effort.  The regback variable says how many characters back from
39  * where regmust matched is the earliest possible start of the match.
40  * For instance, /[a-z].foo/ has a regmust of 'foo' and a regback of 2.]
41  */
42 
43 /*
44  * Structure for regexp "program".  This is essentially a linear encoding
45  * of a nondeterministic finite-state machine (aka syntax charts or
46  * "railroad normal form" in parsing technology).  Each node is an opcode
47  * plus a "next" pointer, possibly plus an operand.  "Next" pointers of
48  * all nodes except BRANCH implement concatenation; a "next" pointer with
49  * a BRANCH on both ends of it is connecting two alternatives.  (Here we
50  * have one of the subtle syntax dependencies:  an individual BRANCH (as
51  * opposed to a collection of them) is never concatenated with anything
52  * because of operator precedence.)  The operand of some types of node is
53  * a literal string; for others, it is a node leading into a sub-FSM.  In
54  * particular, the operand of a BRANCH node is the first node of the branch.
55  * (NB this is *not* a tree structure:  the tail of the branch connects
56  * to the thing following the set of BRANCHes.)  The opcodes are:
57  */
58 
59 /*
60  * A node is one char of opcode followed by two chars of "next" pointer.
61  * "Next" pointers are stored as two 8-bit pieces, high order first.  The
62  * value is a positive offset from the opcode of the node containing it.
63  * An operand, if any, simply follows the node.  (Note that much of the
64  * code generation knows about this implicit relationship.)
65  *
66  * Using two bytes for the "next" pointer is vast overkill for most things,
67  * but allows patterns to get big without disasters.
68  *
69  * [The "next" pointer is always aligned on an even
70  * boundary, and reads the offset directly as a short.  Also, there is no
71  * special test to reverse the sign of BACK pointers since the offset is
72  * stored negative.]
73  */
74 
75 struct regnode_string {
76     U8	str_len;
77     U8  type;
78     U16 next_off;
79     char string[1];
80 };
81 
82 struct regnode_1 {
83     U8	flags;
84     U8  type;
85     U16 next_off;
86     U32 arg1;
87 };
88 
89 struct regnode_2 {
90     U8	flags;
91     U8  type;
92     U16 next_off;
93     U16 arg1;
94     U16 arg2;
95 };
96 
97 #define ANYOF_BITMAP_SIZE	32	/* 256 b/(8 b/B) */
98 #define ANYOF_CLASSBITMAP_SIZE	 4	/* up to 32 (8*4) named classes */
99 
100 struct regnode_charclass {
101     U8	flags;
102     U8  type;
103     U16 next_off;
104     U32 arg1;
105     char bitmap[ANYOF_BITMAP_SIZE];	/* only compile-time */
106 };
107 
108 struct regnode_charclass_class {	/* has [[:blah:]] classes */
109     U8	flags;				/* should have ANYOF_CLASS here */
110     U8  type;
111     U16 next_off;
112     U32 arg1;
113     char bitmap[ANYOF_BITMAP_SIZE];		/* both compile-time */
114     char classflags[ANYOF_CLASSBITMAP_SIZE];	/* and run-time */
115 };
116 
117 /* XXX fix this description.
118    Impose a limit of REG_INFTY on various pattern matching operations
119    to limit stack growth and to avoid "infinite" recursions.
120 */
121 /* The default size for REG_INFTY is I16_MAX, which is the same as
122    SHORT_MAX (see perl.h).  Unfortunately I16 isn't necessarily 16 bits
123    (see handy.h).  On the Cray C90, sizeof(short)==4 and hence I16_MAX is
124    ((1<<31)-1), while on the Cray T90, sizeof(short)==8 and I16_MAX is
125    ((1<<63)-1).  To limit stack growth to reasonable sizes, supply a
126    smaller default.
127 	--Andy Dougherty  11 June 1998
128 */
129 #if SHORTSIZE > 2
130 #  ifndef REG_INFTY
131 #    define REG_INFTY ((1<<15)-1)
132 #  endif
133 #endif
134 
135 #ifndef REG_INFTY
136 #  define REG_INFTY I16_MAX
137 #endif
138 
139 #define ARG_VALUE(arg) (arg)
140 #define ARG__SET(arg,val) ((arg) = (val))
141 
142 #undef ARG
143 #undef ARG1
144 #undef ARG2
145 
146 #define ARG(p) ARG_VALUE(ARG_LOC(p))
147 #define ARG1(p) ARG_VALUE(ARG1_LOC(p))
148 #define ARG2(p) ARG_VALUE(ARG2_LOC(p))
149 #define ARG_SET(p, val) ARG__SET(ARG_LOC(p), (val))
150 #define ARG1_SET(p, val) ARG__SET(ARG1_LOC(p), (val))
151 #define ARG2_SET(p, val) ARG__SET(ARG2_LOC(p), (val))
152 
153 #undef NEXT_OFF
154 #undef NODE_ALIGN
155 
156 #define NEXT_OFF(p) ((p)->next_off)
157 #define NODE_ALIGN(node)
158 #define NODE_ALIGN_FILL(node) ((node)->flags = 0xde) /* deadbeef */
159 
160 #define SIZE_ALIGN NODE_ALIGN
161 
162 #undef OP
163 #undef OPERAND
164 #undef MASK
165 #undef STRING
166 
167 #define	OP(p)		((p)->type)
168 #define	OPERAND(p)	(((struct regnode_string *)p)->string)
169 #define MASK(p)		((char*)OPERAND(p))
170 #define	STR_LEN(p)	(((struct regnode_string *)p)->str_len)
171 #define	STRING(p)	(((struct regnode_string *)p)->string)
172 #define STR_SZ(l)	((l + sizeof(regnode) - 1) / sizeof(regnode))
173 #define NODE_SZ_STR(p)	(STR_SZ(STR_LEN(p))+1)
174 
175 #undef NODE_ALIGN
176 #undef ARG_LOC
177 #undef NEXTOPER
178 #undef PREVOPER
179 
180 #define	NODE_ALIGN(node)
181 #define	ARG_LOC(p)	(((struct regnode_1 *)p)->arg1)
182 #define	ARG1_LOC(p)	(((struct regnode_2 *)p)->arg1)
183 #define	ARG2_LOC(p)	(((struct regnode_2 *)p)->arg2)
184 #define NODE_STEP_REGNODE	1	/* sizeof(regnode)/sizeof(regnode) */
185 #define EXTRA_STEP_2ARGS	EXTRA_SIZE(struct regnode_2)
186 
187 #define NODE_STEP_B	4
188 
189 #define	NEXTOPER(p)	((p) + NODE_STEP_REGNODE)
190 #define	PREVOPER(p)	((p) - NODE_STEP_REGNODE)
191 
192 #define FILL_ADVANCE_NODE(ptr, op) STMT_START { \
193     (ptr)->type = op;    (ptr)->next_off = 0;   (ptr)++; } STMT_END
194 #define FILL_ADVANCE_NODE_ARG(ptr, op, arg) STMT_START { \
195     ARG_SET(ptr, arg);  FILL_ADVANCE_NODE(ptr, op); (ptr) += 1; } STMT_END
196 
197 #define REG_MAGIC 0234
198 
199 #define SIZE_ONLY (RExC_emit == &PL_regdummy)
200 
201 /* Flags for node->flags of ANYOF */
202 
203 #define ANYOF_CLASS		0x08	/* has [[:blah:]] classes */
204 #define ANYOF_INVERT		0x04
205 #define ANYOF_FOLD		0x02
206 #define ANYOF_LOCALE		0x01
207 
208 /* Used for regstclass only */
209 #define ANYOF_EOS		0x10		/* Can match an empty string too */
210 
211 /* There is a character or a range past 0xff */
212 #define ANYOF_UNICODE		0x20
213 #define ANYOF_UNICODE_ALL	0x40	/* Can match any char past 0xff */
214 
215 /* size of node is large (includes class pointer) */
216 #define ANYOF_LARGE 		0x80
217 
218 /* Are there any runtime flags on in this node? */
219 #define ANYOF_RUNTIME(s)	(ANYOF_FLAGS(s) & 0x0f)
220 
221 #define ANYOF_FLAGS_ALL		0xff
222 
223 /* Character classes for node->classflags of ANYOF */
224 /* Should be synchronized with a table in regprop() */
225 /* 2n should pair with 2n+1 */
226 
227 #define ANYOF_ALNUM	 0	/* \w, PL_utf8_alnum, utf8::IsWord, ALNUM */
228 #define ANYOF_NALNUM	 1
229 #define ANYOF_SPACE	 2	/* \s */
230 #define ANYOF_NSPACE	 3
231 #define ANYOF_DIGIT	 4
232 #define ANYOF_NDIGIT	 5
233 #define ANYOF_ALNUMC	 6	/* isalnum(3), utf8::IsAlnum, ALNUMC */
234 #define ANYOF_NALNUMC	 7
235 #define ANYOF_ALPHA	 8
236 #define ANYOF_NALPHA	 9
237 #define ANYOF_ASCII	10
238 #define ANYOF_NASCII	11
239 #define ANYOF_CNTRL	12
240 #define ANYOF_NCNTRL	13
241 #define ANYOF_GRAPH	14
242 #define ANYOF_NGRAPH	15
243 #define ANYOF_LOWER	16
244 #define ANYOF_NLOWER	17
245 #define ANYOF_PRINT	18
246 #define ANYOF_NPRINT	19
247 #define ANYOF_PUNCT	20
248 #define ANYOF_NPUNCT	21
249 #define ANYOF_UPPER	22
250 #define ANYOF_NUPPER	23
251 #define ANYOF_XDIGIT	24
252 #define ANYOF_NXDIGIT	25
253 #define ANYOF_PSXSPC	26	/* POSIX space: \s plus the vertical tab */
254 #define ANYOF_NPSXSPC	27
255 #define ANYOF_BLANK	28	/* GNU extension: space and tab: non-vertical space */
256 #define ANYOF_NBLANK	29
257 
258 #define ANYOF_MAX	32
259 
260 /* Backward source code compatibility. */
261 
262 #define ANYOF_ALNUML	 ANYOF_ALNUM
263 #define ANYOF_NALNUML	 ANYOF_NALNUM
264 #define ANYOF_SPACEL	 ANYOF_SPACE
265 #define ANYOF_NSPACEL	 ANYOF_NSPACE
266 
267 /* Utility macros for the bitmap and classes of ANYOF */
268 
269 #define ANYOF_SIZE		(sizeof(struct regnode_charclass))
270 #define ANYOF_CLASS_SIZE	(sizeof(struct regnode_charclass_class))
271 
272 #define ANYOF_FLAGS(p)		((p)->flags)
273 
274 #define ANYOF_BIT(c)		(1 << ((c) & 7))
275 
276 #define ANYOF_CLASS_BYTE(p, c)	(((struct regnode_charclass_class*)(p))->classflags[((c) >> 3) & 3])
277 #define ANYOF_CLASS_SET(p, c)	(ANYOF_CLASS_BYTE(p, c) |=  ANYOF_BIT(c))
278 #define ANYOF_CLASS_CLEAR(p, c)	(ANYOF_CLASS_BYTE(p, c) &= ~ANYOF_BIT(c))
279 #define ANYOF_CLASS_TEST(p, c)	(ANYOF_CLASS_BYTE(p, c) &   ANYOF_BIT(c))
280 
281 #define ANYOF_CLASS_ZERO(ret)	Zero(((struct regnode_charclass_class*)(ret))->classflags, ANYOF_CLASSBITMAP_SIZE, char)
282 #define ANYOF_BITMAP_ZERO(ret)	Zero(((struct regnode_charclass*)(ret))->bitmap, ANYOF_BITMAP_SIZE, char)
283 
284 #define ANYOF_BITMAP(p)		(((struct regnode_charclass*)(p))->bitmap)
285 #define ANYOF_BITMAP_BYTE(p, c)	(ANYOF_BITMAP(p)[((c) >> 3) & 31])
286 #define ANYOF_BITMAP_SET(p, c)	(ANYOF_BITMAP_BYTE(p, c) |=  ANYOF_BIT(c))
287 #define ANYOF_BITMAP_CLEAR(p,c)	(ANYOF_BITMAP_BYTE(p, c) &= ~ANYOF_BIT(c))
288 #define ANYOF_BITMAP_TEST(p, c)	(ANYOF_BITMAP_BYTE(p, c) &   ANYOF_BIT(c))
289 
290 #define ANYOF_BITMAP_SETALL(p)		\
291 	memset (ANYOF_BITMAP(p), 255, ANYOF_BITMAP_SIZE)
292 #define ANYOF_BITMAP_CLEARALL(p)	\
293 	Zero (ANYOF_BITMAP(p), ANYOF_BITMAP_SIZE)
294 /* Check that all 256 bits are all set.  Used in S_cl_is_anything()  */
295 #define ANYOF_BITMAP_TESTALLSET(p)	\
296 	memEQ (ANYOF_BITMAP(p), "\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377", ANYOF_BITMAP_SIZE)
297 
298 #define ANYOF_SKIP		((ANYOF_SIZE - 1)/sizeof(regnode))
299 #define ANYOF_CLASS_SKIP	((ANYOF_CLASS_SIZE - 1)/sizeof(regnode))
300 #define ANYOF_CLASS_ADD_SKIP	(ANYOF_CLASS_SKIP - ANYOF_SKIP)
301 
302 /*
303  * Utility definitions.
304  */
305 #ifndef CHARMASK
306 #  define UCHARAT(p)	((int)*(const U8*)(p))
307 #else
308 #  define UCHARAT(p)	((int)*(p)&CHARMASK)
309 #endif
310 
311 #define EXTRA_SIZE(guy) ((sizeof(guy)-1)/sizeof(struct regnode))
312 
313 #define REG_SEEN_ZERO_LEN	 1
314 #define REG_SEEN_LOOKBEHIND	 2
315 #define REG_SEEN_GPOS		 4
316 #define REG_SEEN_EVAL		 8
317 #define REG_SEEN_CANY		16
318 #define REG_SEEN_SANY		REG_SEEN_CANY /* src bckwrd cmpt */
319 
320 START_EXTERN_C
321 
322 #include "regnodes.h"
323 
324 /* The following have no fixed length. U8 so we can do strchr() on it. */
325 #ifndef DOINIT
326 EXTCONST U8 PL_varies[];
327 #else
328 EXTCONST U8 PL_varies[] = {
329     BRANCH, BACK, STAR, PLUS, CURLY, CURLYX, REF, REFF, REFFL,
330     WHILEM, CURLYM, CURLYN, BRANCHJ, IFTHEN, SUSPEND, CLUMP, 0
331 };
332 #endif
333 
334 /* The following always have a length of 1. U8 we can do strchr() on it. */
335 /* (Note that length 1 means "one character" under UTF8, not "one octet".) */
336 #ifndef DOINIT
337 EXTCONST U8 PL_simple[];
338 #else
339 EXTCONST U8 PL_simple[] = {
340     REG_ANY,	SANY,	CANY,
341     ANYOF,
342     ALNUM,	ALNUML,
343     NALNUM,	NALNUML,
344     SPACE,	SPACEL,
345     NSPACE,	NSPACEL,
346     DIGIT,	NDIGIT,
347     0
348 };
349 #endif
350 
351 END_EXTERN_C
352 
353 typedef struct re_scream_pos_data_s
354 {
355     char **scream_olds;		/* match pos */
356     I32 *scream_pos;		/* Internal iterator of scream. */
357 } re_scream_pos_data;
358 
359 /* .what is a character array with one character for each member of .data
360  * The character describes the function of the corresponding .data item:
361  *   f - start-class data for regstclass optimization
362  *   n - Root of op tree for (?{EVAL}) item
363  *   o - Start op for (?{EVAL}) item
364  *   p - Pad for (?{EVAL} item
365  *   s - swash for unicode-style character class, and the multicharacter
366  *       strings resulting from casefolding the single-character entries
367  *       in the character class
368  * 20010712 mjd@plover.com
369  * (Remember to update re_dup() and pregfree() if you add any items.)
370  */
371 struct reg_data {
372     U32 count;
373     U8 *what;
374     void* data[1];
375 };
376 
377 struct reg_substr_datum {
378     I32 min_offset;
379     I32 max_offset;
380     SV *substr;		/* non-utf8 variant */
381     SV *utf8_substr;	/* utf8 variant */
382 };
383 
384 struct reg_substr_data {
385     struct reg_substr_datum data[3];	/* Actual array */
386 };
387 
388 #define anchored_substr substrs->data[0].substr
389 #define anchored_utf8 substrs->data[0].utf8_substr
390 #define anchored_offset substrs->data[0].min_offset
391 #define float_substr substrs->data[1].substr
392 #define float_utf8 substrs->data[1].utf8_substr
393 #define float_min_offset substrs->data[1].min_offset
394 #define float_max_offset substrs->data[1].max_offset
395 #define check_substr substrs->data[2].substr
396 #define check_utf8 substrs->data[2].utf8_substr
397 #define check_offset_min substrs->data[2].min_offset
398 #define check_offset_max substrs->data[2].max_offset
399