xref: /illumos-gate/usr/src/cmd/sgs/lex/common/sub3.c (revision 123e0aa3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * sub3.c ... ALE enhancement.
28  * Since a typical Asian language has a huge character set, it is not
29  * ideal to index an array by a character code itself, which requires
30  * as large as 2**16 entries per array.
31  * To get arround this problem, we identify a set of characters that
32  * causes the same transition on all states and call it character group.
33  * Every character in a same character group has a unique number called
34  * character group id.  A function yycgid(c) maps the character c (in process
35  * code) to the id.  This mapping is determined by analyzing all regular
36  * expressions in the lex program.
37  *
38  */
39 #include	<stdlib.h>
40 #include	<widec.h>
41 #include	<search.h>
42 #include	"ldefs.h"
43 
44 /*
45  * "lchar" stands for linearized character.  It is a variant of
46  * process code.  AT&T's 16-bit process code has a drawback in which
47  * for three three process code C, D and E where C <= D <= E,
48  * codeset(C)==codeset(E) does not mean codeset(D)==codeset(C).
49  * In other words, four codesets alternates as the magnitude
50  * of character increases.
51  * The lchar representation holds this property:
52  *   If three lchar C', D' and E' have the relationship C' < D' <  E' and
53  *   codeset(C') == codeset(E') then D' is guaranteed to belong to
54  *   the same codeset as C' and E'.
55  * lchar is implemented as 32 bit entities and the function linearize()
56  * that maps a wchar_t to lchar is defined below.  There is no
57  * reverse function for it though.
58  * The 32-bit process code by AT&T, used only for Taiwanese version at the
59  * time of wrting, has no such problem and we use it as it is.
60  */
61 
62 lchar	yycgidtbl[MAXNCG] = {
63 	0,		/* For ease of computation of the id. */
64 	'\n',		/* Newline is always special because '.' exclude it. */
65 	0x000000ff,	/* The upper limit of codeset 0. */
66 	0x20ffffff,	/* The upper limit of codeset 2. */
67 	0x40ffffff	/* The upper limit of codeset 3. */
68 /*	0x60ffffff	   The upper limit of codeset 1. */
69 	/* Above assumes the number of significant bits of wchar_t is <= 24. */
70 };
71 int	ncgidtbl = 5; /* # elements in yycgidtbl. */
72 int	ncg; /* Should set to ncgidtbl*2; this is the largest value yycgid() */
73 		/* returns plus 1. */
74 
75 static void setsymbol(int i);
76 
77 /*
78  * For given 16-bit wchar_t (See NOTE), lchar is computed as illustrated below:
79  *
80  *	wc: axxxxxxbyyyyyyy
81  *
82  * returns: 0ab0000000000000axxxxxxxbyyyyyyy
83  *
84  * linearize() doesn't do any if compiled with 32-bit wchar_t, use of
85  * which is flagged with LONG_WCHAR_T macro.
86  * NOTE:
87  * The implementation is highly depends on the process code representation.
88  * This function should be modified when 32-bit process code is used.
89  * There is no need to keep 'a' and 'b' bits in the lower half of lchar.
90  * You can actually omit these and squeeze the xxxxxx part one bit right.
91  * We don't do that here just in sake of speed.
92  */
93 lchar
94 linearize(wchar_t wc)
95 {
96 #ifdef LONG_WCHAR_T
97 	return ((lchar)wc); /* Don't do anything. */
98 #else
99 
100 	lchar	prefix;
101 	switch (wc&0x8080) {
102 	case 0x0000: prefix = 0x00000000; break;
103 	case 0x0080: prefix = 0x20000000; break;
104 	case 0x8000: prefix = 0x40000000; break;
105 	case 0x8080: prefix = 0x60000000; break;
106 	}
107 	return (prefix|wc);
108 #endif
109 }
110 
111 /* compare liniear characters pointed to by pc1 and pc2 */
112 int
113 cmplc(const void *arg1, const void *arg2)
114 {
115 	lchar *pc1 = (lchar *)arg1;
116 	lchar *pc2 = (lchar *)arg2;
117 
118 	if (*pc1 > *pc2)
119 		return (1);
120 	else if (*pc1 == *pc2)
121 		return (0);
122 	else
123 		return (-1);
124 }
125 
126 void
127 remch(wchar_t c)
128 {
129 	lchar	lc = linearize(c);
130 	size_t	local_ncgidtbl;
131 
132 	/*
133 	 * User-friendliness consideration:
134 	 * Make sure no EUC chars are used in reg. exp.
135 	 */
136 	if (!handleeuc) {
137 		if (!isascii(c))
138 			if (iswprint(c))
139 				warning(
140 "Non-ASCII character '%wc' in pattern; use -w or -e lex option.", c);
141 			else warning(
142 "Non-ASCII character of value %#x in pattern; use -w or -e lex option.", c);
143 		/* In any case, we don't need to construct ncgidtbl[]. */
144 		return;
145 	}
146 
147 	/*
148 	 * lsearch wants ncgidtbl to be size_t, but it is int. Hence,
149 	 * the use of local_ncgidtbl to satisfy the calling interface.
150 	 */
151 	local_ncgidtbl = ncgidtbl;
152 	(void) lsearch(&lc, yycgidtbl,
153 	    &local_ncgidtbl, sizeof (lchar), cmplc);
154 	ncgidtbl = (int)local_ncgidtbl;
155 }
156 
157 void
158 sortcgidtbl(void)
159 {
160 	if (!handleeuc)
161 		return;
162 	qsort(yycgidtbl, ncgidtbl, sizeof (lchar), cmplc);
163 }
164 
165 /*
166  * int yycgid(wchar_t c)
167  *	Takes c and returns its character group id, determind by the
168  *	following algorithm.  The program also uses the binary search
169  *	algorithm, generalized from Knuth (6.2.1) Algorithm B.
170  *
171  *	This function computes the "character group id" based on
172  *	a table yycgidtbl of which each lchar entry is pre-sorted
173  *	in ascending sequence  The number of valid entries is given
174  *	by YYNCGIDTBL.  There is no duplicate entries in yycgidtbl.
175  *		const int YYNCGIDTBL;
176  *		lchar	yycgidtbl[YYNCGIDTBL];
177  *
178  *	yycgidtbl[0] is guaranteed to have zero.
179  *
180  *	For given c, yycgid(c) returns:
181  *		2*i	iff yycgidtbl[i] == lc
182  *		2*i+1	iff yycgidtbl[i] < lc < yycgidtbl[i+1]
183  *		YYNCGIDTBL*2-1
184  *			iff yycgidtbl[YYNCGIDTBL-1] < lc
185  *	where lc=linearize(c).
186  *
187  *	Some interesting properties.:
188  *	1.  For any c, 0 <= yycgid(c) <= 2*YYNCGIDTBL-1
189  *	2.  yycgid(c) == 0  iff  c == 0.
190  *	3.  For any wchar_t c and d, if linearize(c) < linearize(d) then
191  *	    yycgid(c) <= yycgid(d).
192  *	4.  For any wchar_t c and d, if yycgid(c) < yycgid(d) then
193  *	    linearize(c) < linearize(d).
194  */
195 #define	YYNCGIDTBL ncgidtbl
196 
197 int
198 yycgid(wchar_t c)
199 {
200 	int first = 0;
201 	int last = YYNCGIDTBL - 1;
202 	lchar lc;
203 
204 	/*
205 	 * In ASCII compat. mode, each character forms a "group" and the
206 	 * group-id is itself...
207 	 */
208 	if (!handleeuc)
209 		return (c);
210 
211 	lc = linearize(c);
212 
213 	/* An exceptional case: yycgidtbl[YYNCGIDTBL-1] < lc */
214 	if (yycgidtbl[YYNCGIDTBL - 1] < lc)
215 		return (YYNCGIDTBL*2 - 1);
216 
217 	while (last >= 0) {
218 		int i = (first+last)/2;
219 		if (lc == yycgidtbl[i])
220 			return (2*i);	/* lc exactly matches an element. */
221 		else if (yycgidtbl[i] < lc) {
222 			if (lc < yycgidtbl[i+1]) {
223 				/* lc is in between two elements */
224 				return (2*i+1);
225 			}
226 			else
227 				first = i + 1;
228 		} else
229 			last = i - 1;
230 	}
231 	error(
232 	"system error in yycgid():binary search failed for c=0x%04x\n", c);
233 	return (0);
234 }
235 
236 /*
237  * repbycgid --- replaces each character in the parsing tree by its
238  * character group id.   This, however, should be called even in
239  * the ASCII compat. mode to process DOT nodes and to call cclinter()
240  * for the DOT and CCL nodes.
241  */
242 void
243 repbycgid(void)
244 {
245 	int i, c;
246 
247 	for (i = 0; i < tptr; ++i) {
248 		c = name[i];
249 		if (!ISOPERATOR(c)) {
250 		/* If not an operator, it must be a char.  */
251 			name[i] = yycgid((wchar_t)c); /* So replace it. */
252 #ifdef DEBUG
253 			if (debug) {
254 				printf("name[%d]:'%c'->%d;\n", i, c, name[i]);
255 			}
256 #endif
257 		} else if (c == RSTR) {
258 			c = right[i];
259 			right[i] = yycgid((wchar_t)c);
260 #ifdef DEBUG
261 			if (debug) {
262 				printf(
263 				    "name[%d].right:'%c'->%d;\n",
264 				    i, c, right[i]);
265 			}
266 #endif
267 		} else if ((c == RCCL) || (c == RNCCL)) {
268 			CHR cc, *s;
269 			int j;
270 			CHR ccltoken[CCLSIZE];
271 			CHR *ccp;
272 			int m;
273 			/*
274 			 * This node represetns a character class RE [ccccc]
275 			 * s points to the string of characters that forms
276 			 * the class and/or a special prefix notation
277 			 * <RANGE>XY which corresponds to the RE X-Y,
278 			 * characters in the range of X and Y.  Here,
279 			 * X <= Y is guranteed.
280 			 * We transform these characters into a string
281 			 * of sorted character group ids.
282 			 *
283 			 * There is another mechanism of packing tables
284 			 * that is inherited from the ASCII lex.  Call of
285 			 * cclinter() is required for this packing.
286 			 * This used to be done as yylex() reads the lex
287 			 * rules but we have to do this here because the
288 			 * transition table is made to work on the char-group
289 			 * ids and the mapping cannot be determined until
290 			 * the entire file is read.
291 			 */
292 #ifdef DEBUG
293 			if (debug) {
294 				printf("name[%d]:R[N]CCL of \"", i);
295 				strpt(left[i]);
296 				printf(" -> {");
297 			}
298 #endif
299 			/* Prepare symbol[] for cclinter(). */
300 			for (j = 0; j < ncg; ++j)
301 				symbol[j] = FALSE;
302 
303 			s = (CHR *) left[i];
304 			while (cc = *s++) {
305 				if (cc == RANGE) {
306 					int	low, high, i;
307 					/*
308 					 * Special form: <RANGE>XY
309 					 * This means the range X-Y.
310 					 * We mark all symbols[]
311 					 * elements for yycgid(X) thru
312 					 * yycgid(Y), inclusively.
313 					 */
314 					low = yycgid(*s++);
315 					high = yycgid(*s++);
316 					for (i = low; i <= high; ++i)
317 						setsymbol(i);
318 				} else {
319 					setsymbol(yycgid(cc));
320 				}
321 			}
322 
323 			/* Now make a transformed string of cgids. */
324 			s = ccptr;
325 			m = 0;
326 			for (j = 0; j < ncg; ++j)
327 				if (symbol[j]) {
328 					ccltoken[m++] = (CHR)j;
329 #ifdef DEBUG
330 					if (debug) printf("%d, ", j);
331 #endif
332 				}
333 
334 #ifdef DEBUG
335 			if (debug) printf("}\n");
336 #endif
337 			ccltoken[m] = 0;
338 			ccp = ccl;
339 			while (ccp < ccptr && scomp(ccltoken, ccp) != 0)
340 				ccp++;
341 			if (ccp < ccptr) {  /* character class found in ccl */
342 				left[i] = (int)ccp;
343 			} else { /* not in ccl, add it */
344 				left[i] = (int)ccptr;
345 				scopy(ccltoken, ccptr);
346 				ccptr += slength(ccltoken) + 1;
347 				if (ccptr > ccl + CCLSIZE)
348 					error(
349 					"Too many large character classes");
350 			}
351 			cclinter(c == RCCL);
352 		} else if (c == DOT) {
353 			if (psave == 0) { /* First DOT node. */
354 				int j, nlid;
355 				/*
356 				 * Make symbol[k]=TRUE for all k
357 				 *  except k == yycgid('\n').
358 				 */
359 				nlid = yycgid('\n');
360 				psave = ccptr;
361 				for (j = 1; j < ncg; ++j) {
362 					if (j == nlid) {
363 						symbol[j] = FALSE;
364 					} else {
365 						symbol[j] = TRUE;
366 						*ccptr++ = (CHR) j;
367 					}
368 				}
369 				*ccptr++ = 0;
370 				if (ccptr > ccl + CCLSIZE)
371 					error(
372 					"Too many large character classes");
373 			}
374 			/* Mimic mn1(RCCL,psave)... */
375 			name[i] = RCCL;
376 			left[i] = (int)psave;
377 			cclinter(1);
378 		}
379 	}
380 #ifdef DEBUG
381 	if (debug) {
382 		printf("treedump after repbycgid().\n");
383 		treedump();
384 	}
385 #endif
386 }
387 
388 static void
389 setsymbol(int i)
390 {
391 	if (i > sizeof (symbol))
392 		error("setsymbol: (SYSERR) %d out of range", i);
393 	symbol[i] = TRUE;
394 }
395