xref: /titanic_41/usr/src/lib/libast/common/sfio/sfstrtof.h (revision b6805bf78d2bbbeeaea8909a05623587b42d58b3)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                   Phong Vo <kpv@research.att.com>                    *
20 *                                                                      *
21 ***********************************************************************/
22 /*
23  * AT&T Research
24  * Glenn Fowler & Phong Vo
25  *
26  * common header and implementation for
27  *
28  *	strtof		strtod		strtold		_sfdscan
29  *	strntof		strntod		strntold
30  *
31  * define these macros to instantiate an implementation:
32  *
33  *	S2F_function	the function name
34  *	S2F_static	<0:export =0:extern >0:static
35  *	S2F_type	0:float 1:double 2:long.double
36  *	S2F_qualifier	1 for optional [fFlL] qualifier suffix
37  *	S2F_size	1 for interface with size_t second arg
38  *	S2F_scan	1 for alternate interface with these arguments:
39  *				void* handle
40  *				int (*getchar)(void* handle, int flag)
41  *			exactly one extra (*getchar)() is done, i.e.,
42  *			the caller must do the pushback
43  *				flag==0		get next char
44  *				flag==1		no number seen
45  *			return 0 on error or EOF
46  */
47 
48 #include "sfhdr.h"
49 #include "FEATURE/float"
50 
51 /*
52  * the default is _sfdscan for standalone sfio compatibility
53  */
54 
55 #if !defined(S2F_function)
56 #define S2F_function	_sfdscan
57 #define S2F_static	1
58 #define S2F_type	2
59 #define S2F_scan	1
60 #ifndef elementsof
61 #define elementsof(a)	(sizeof(a)/sizeof(a[0]))
62 #endif
63 #endif
64 
65 #if S2F_type == 2 && _ast_fltmax_double
66 #undef	S2F_type
67 #define S2F_type	1
68 #endif
69 
70 #if S2F_type == 0
71 #define S2F_number	float
72 #define S2F_ldexp	ldexp
73 #define S2F_pow10	_Sffpow10
74 #define S2F_inf		_Sffinf
75 #define S2F_nan		_Sffnan
76 #define S2F_min		(FLT_MIN)
77 #define S2F_max		(FLT_MAX)
78 #define S2F_exp_10_min	(FLT_MIN_10_EXP)
79 #define S2F_exp_10_max	(FLT_MAX_10_EXP)
80 #define S2F_exp_2_min	(FLT_MIN_EXP)
81 #define S2F_exp_2_max	(FLT_MAX_EXP)
82 #endif
83 #if S2F_type == 1
84 #define S2F_number	double
85 #define S2F_ldexp	ldexp
86 #define S2F_pow10	_Sfdpow10
87 #define S2F_inf		_Sfdinf
88 #define S2F_nan		_Sfdnan
89 #define S2F_min		(DBL_MIN)
90 #define S2F_max		(DBL_MAX)
91 #define S2F_exp_10_min	(DBL_MIN_10_EXP)
92 #define S2F_exp_10_max	(DBL_MAX_10_EXP)
93 #define S2F_exp_2_min	(DBL_MIN_EXP)
94 #define S2F_exp_2_max	(DBL_MAX_EXP)
95 #endif
96 #if S2F_type == 2
97 #define S2F_number	long double
98 #define S2F_ldexp	ldexpl
99 #define S2F_pow10	_Sflpow10
100 #define S2F_inf		_Sflinf
101 #define S2F_nan		_Sflnan
102 #define S2F_min		(LDBL_MIN)
103 #define S2F_max		(LDBL_MAX)
104 #define S2F_exp_10_min	(LDBL_MIN_10_EXP)
105 #define S2F_exp_10_max	(LDBL_MAX_10_EXP)
106 #define S2F_exp_2_min	(LDBL_MIN_EXP)
107 #define S2F_exp_2_max	(LDBL_MAX_EXP)
108 #endif
109 
110 #if -S2F_exp_10_min < S2F_exp_10_max
111 #define S2F_exp_10_abs	(-S2F_exp_10_min)
112 #else
113 #define S2F_exp_10_abs	S2F_exp_10_max
114 #endif
115 
116 #define S2F_batch	_ast_flt_unsigned_max_t
117 
118 #undef	ERR		/* who co-opted this namespace? */
119 
120 #if S2F_scan
121 
122 typedef int (*S2F_get_f)_ARG_((void*, int));
123 
124 #define ERR(e)
125 #define GET(p)		(*get)(p,0)
126 #define NON(p)		(*get)(p,1)
127 #define PUT(p)
128 #define REV(p,t,b)
129 #define SET(p,t,b)
130 
131 #else
132 
133 #define ERR(e)		(errno=(e))
134 #define NON(p)
135 
136 #if S2F_size
137 #define GET(p)		(((p)<(z))?(*p++):(back=0))
138 #define PUT(p)		(end?(*end=(char*)p-back):(char*)0)
139 #define REV(p,t,b)	(p=t,back=b)
140 #define SET(p,t,b)	(t=p,b=back)
141 #else
142 #define GET(p)		(*p++)
143 #define PUT(p)		(end?(*end=(char*)p-1):(char*)0)
144 #define REV(p,t,b)	(p=t)
145 #define SET(p,t,b)	(t=p)
146 #endif
147 
148 #endif
149 
150 typedef struct S2F_part_s
151 {
152 	S2F_batch	batch;
153 	int		digits;
154 } S2F_part_t;
155 
156 #if !defined(ERANGE)
157 #define ERANGE		EINVAL
158 #endif
159 
160 #if S2F_static > 0
161 static
162 #else
163 #if S2F_static < 0 || !defined(S2F_static)
164 #if defined(__EXPORT__)
165 #define extern		__EXPORT__
166 #endif
167 extern
168 #undef	extern
169 #endif
170 #endif
171 S2F_number
172 #if S2F_scan
173 #if __STD_C
174 S2F_function(void* s, S2F_get_f get)
175 #else
176 S2F_function(s, get) void* s; S2F_get_f get;
177 #endif
178 #else
179 #if S2F_size
180 #if __STD_C
181 S2F_function(const char* str, size_t size, char** end)
182 #else
183 S2F_function(str, size, end) char* str; size_t size; char** end;
184 #endif
185 #else
186 #if __STD_C
187 S2F_function(const char* str, char** end)
188 #else
189 S2F_function(str, end) char* str; char** end;
190 #endif
191 #endif
192 #endif
193 {
194 #if !S2F_scan
195 	register unsigned char*	s = (unsigned char*)str;
196 #if S2F_size
197 	register unsigned char*	z = s + size;
198 	int			back = 1;
199 	int			b;
200 #endif
201 	unsigned char*		t;
202 #endif
203 	register S2F_batch	n;
204 	register int		c;
205 	register int		digits;
206 	register int		m;
207 	register unsigned char*	cv;
208 	int			negative;
209 	int			enegative;
210 	int			fraction;
211 	int			decimal = 0;
212 	int			thousand = 0;
213 	int			part = 0;
214 	S2F_number		v;
215 	S2F_number		p;
216 	S2F_part_t		parts[16];
217 
218 	/*
219 	 * radix char and thousands separator are locale specific
220 	 */
221 
222 	SFSETLOCALE(&decimal, &thousand);
223 	SFCVINIT();
224 
225 	/*
226 	 * skip initial blanks
227 	 */
228 
229 	do c = GET(s); while (isspace(c));
230 	SET(s, t, b);
231 
232 	/*
233 	 * get the sign
234 	 */
235 
236 	if ((negative = (c == '-')) || c == '+')
237 		c = GET(s);
238 
239 	/*
240 	 * drop leading 0's
241 	 */
242 
243 	digits = 0;
244 	fraction = -1;
245 	if (c == '0')
246 	{
247 		c = GET(s);
248 		if (c == 'x' || c == 'X')
249 		{
250 			/*
251 			 * hex floating point -- easy
252 			 */
253 
254 			cv = _Sfcv36;
255 			v = 0;
256 			for (;;)
257 			{
258 				c = GET(s);
259 				if ((part = cv[c]) < 16)
260 				{
261 					digits++;
262 					v *= 16;
263 					v += part;
264 				}
265 				else if (c == decimal)
266 				{
267 					decimal = -1;
268 					fraction = digits;
269 				}
270 				else
271 					break;
272 			}
273 			m = 0;
274 			if (c == 'p' || c == 'P')
275 			{
276 				c = GET(s);
277 				if ((enegative = c == '-') || c == '+')
278 					c = GET(s);
279 				while (c >= '0' && c <= '9')
280 				{
281 					m = (m << 3) + (m << 1) + (c - '0');
282 					c = GET(s);
283 				}
284 				if (enegative)
285 					m = -m;
286 			}
287 
288 #if S2F_qualifier
289 
290 			/*
291 			 * consume the optional suffix
292 			 */
293 
294 			switch (c)
295 			{
296 			case 'f':
297 			case 'F':
298 			case 'l':
299 			case 'L':
300 				c = GET(s);
301 				break;
302 			}
303 #endif
304 			PUT(s);
305 			if (v == 0)
306 				return negative ? -v : v;
307 			if (fraction >= 0)
308 				m -= 4 * (digits - fraction);
309 			if (m < S2F_exp_2_min)
310 			{
311 				if ((m -= S2F_exp_2_min) < S2F_exp_2_min)
312 				{
313 					ERR(ERANGE);
314 					return 0;
315 				}
316 				v = S2F_ldexp(v, S2F_exp_2_min);
317 			}
318 			else if (m > S2F_exp_2_max)
319 			{
320 				ERR(ERANGE);
321 				return negative ? -S2F_inf : S2F_inf;
322 			}
323 			v = S2F_ldexp(v, m);
324 			goto check;
325 		}
326 		while (c == '0')
327 			c = GET(s);
328 	}
329 	else if (c == decimal)
330 	{
331 		decimal = -1;
332 		fraction = 0;
333 		for (;;)
334 		{
335 			c = GET(s);
336 			if (c != '0')
337 				break;
338 			digits++;
339 		}
340 	}
341 	else if (c == 'i' || c == 'I')
342 	{
343 		if ((c = GET(s)) != 'n' && c != 'N' ||
344 		    (c = GET(s)) != 'f' && c != 'F')
345 		{
346 			REV(s, t, b);
347 			PUT(s);
348 			return 0;
349 		}
350 		c = GET(s);
351 		SET(s, t, b);
352 		if (((c)          == 'i' || c == 'I') &&
353 		    ((c = GET(s)) == 'n' || c == 'N') &&
354 		    ((c = GET(s)) == 'i' || c == 'I') &&
355 		    ((c = GET(s)) == 't' || c == 'T') &&
356 		    ((c = GET(s)) == 'y' || c == 'Y'))
357 		{
358 			c = GET(s);
359 			SET(s, t, b);
360 		}
361 		REV(s, t, b);
362 		PUT(s);
363 		return negative ? -S2F_inf : S2F_inf;
364 	}
365 	else if (c == 'n' || c == 'N')
366 	{
367 		if ((c = GET(s)) != 'a' && c != 'A' ||
368 		    (c = GET(s)) != 'n' && c != 'N')
369 		{
370 			REV(s, t, b);
371 			PUT(s);
372 			return 0;
373 		}
374 		do c = GET(s); while (c && !isspace(c));
375 		PUT(s);
376 		return negative ? -S2F_nan : S2F_nan;
377 	}
378 	else if (c < '1' || c > '9')
379 	{
380 		REV(s, t, b);
381 		PUT(s);
382 		NON(s);
383 		return 0;
384 	}
385 
386 	/*
387 	 * consume the integral and fractional parts
388 	 */
389 
390 	n = 0;
391 	m = 0;
392 	for (;;)
393 	{
394 		if (c >= '0' && c <= '9')
395 		{
396 			digits++;
397 			n = (n << 3) + (n << 1) + (c - '0');
398 			if (n >= ((~((S2F_batch)0)) / 10) && part < elementsof(parts))
399 			{
400 				parts[part].batch = n;
401 				n = 0;
402 				parts[part].digits = digits;
403 				part++;
404 			}
405 		}
406 		else if (m && (digits - m) != 3)
407 			break;
408 		else if (c == decimal)
409 		{
410 			decimal = -1;
411 			thousand = -1;
412 			m = 0;
413 			fraction = digits;
414 		}
415 		else if (c != thousand)
416 			break;
417 		else if (!(m = digits))
418 			break;
419 		c = GET(s);
420 	}
421 
422 	/*
423 	 * don't forget the last part
424 	 */
425 
426 	if (n && part < elementsof(parts))
427 	{
428 		parts[part].batch = n;
429 		parts[part].digits = digits;
430 		part++;
431 	}
432 
433 	/*
434 	 * consume the exponent
435 	 */
436 
437 	if (fraction >= 0)
438 		digits = fraction;
439 	if (c == 'e' || c == 'E')
440 	{
441 		c = GET(s);
442 		if ((enegative = (c == '-')) || c == '+')
443 			c = GET(s);
444 		n = 0;
445 		while (c >= '0' && c <= '9')
446 		{
447 			n = (n << 3) + (n << 1) + (c - '0');
448 			c = GET(s);
449 		}
450 		if (enegative)
451 			digits -= n;
452 		else
453 			digits += n;
454 	}
455 
456 #if S2F_qualifier
457 
458 	/*
459 	 * consume the optional suffix
460 	 */
461 
462 	switch (c)
463 	{
464 	case 'f':
465 	case 'F':
466 	case 'l':
467 	case 'L':
468 		c = GET(s);
469 		break;
470 	}
471 #endif
472 	PUT(s);
473 
474 	/*
475 	 * adjust for at most one multiply per part
476 	 * and at most one divide overall
477 	 */
478 
479 	v = 0;
480 	if (!part)
481 		return negative ? -v : v;
482 	else if ((m = parts[part-1].digits - digits) > 0)
483 		digits += m;
484 	else
485 		m = 0;
486 
487 	/*
488 	 * combine the parts
489 	 */
490 
491 	while (part--)
492 	{
493 		p = parts[part].batch;
494 		c = digits - parts[part].digits;
495 		if (c > S2F_exp_10_max)
496 		{
497 			ERR(ERANGE);
498 			return negative ? -S2F_inf : S2F_inf;
499 		}
500 		if (c > 0)
501 		{
502 #if _ast_mpy_overflow_fpe
503 			if ((S2F_max / p) < S2F_pow10[c])
504 			{
505 				ERR(ERANGE);
506 				return negative ? -S2F_inf : S2F_inf;
507 			}
508 #endif
509 			p *= S2F_pow10[c];
510 		}
511 		v += p;
512 	}
513 	if (m)
514 	{
515 		while (m > S2F_exp_10_max)
516 		{
517 			m -= S2F_exp_10_max;
518 			v /= S2F_pow10[S2F_exp_10_max];
519 		}
520 #if _ast_div_underflow_fpe
521 		if ((S2F_min * p) > S2F_pow10[c])
522 		{
523 			ERR(ERANGE);
524 			return negative ? -S2F_inf : S2F_inf;
525 		}
526 #endif
527 		v /= S2F_pow10[m];
528 	}
529 
530 	/*
531 	 * check the range
532 	 */
533 
534  check:
535 	if (v < S2F_min)
536 	{
537 		ERR(ERANGE);
538 		v = 0;
539 	}
540 	else if (v > S2F_max)
541 	{
542 		ERR(ERANGE);
543 		v = S2F_inf;
544 	}
545 
546 	/*
547 	 * done
548 	 */
549 
550 	return negative ? -v : v;
551 }
552