1 
2 #line 1 "hb-number-parser.rl"
3 /*
4  * Copyright © 2019  Ebrahim Byagowi
5  *
6  *  This is part of HarfBuzz, a text shaping library.
7  *
8  * Permission is hereby granted, without written agreement and without
9  * license or royalty fees, to use, copy, modify, and distribute this
10  * software and its documentation for any purpose, provided that the
11  * above copyright notice and the following two paragraphs appear in
12  * all copies of this software.
13  *
14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18  * DAMAGE.
19  *
20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25  *
26  */
27 
28 #ifndef HB_NUMBER_PARSER_HH
29 #define HB_NUMBER_PARSER_HH
30 
31 #include "hb.hh"
32 
33 #include <float.h>
34 
35 
36 #line 37 "hb-number-parser.hh"
37 static const unsigned char _double_parser_trans_keys[] = {
38 	0u, 0u, 43u, 57u, 46u, 57u, 48u, 57u, 43u, 57u, 48u, 57u, 48u, 101u, 48u, 57u,
39 	46u, 101u, 0
40 };
41 
42 static const char _double_parser_key_spans[] = {
43 	0, 15, 12, 10, 15, 10, 54, 10,
44 	56
45 };
46 
47 static const unsigned char _double_parser_index_offsets[] = {
48 	0, 0, 16, 29, 40, 56, 67, 122,
49 	133
50 };
51 
52 static const char _double_parser_indicies[] = {
53 	0, 1, 2, 3, 1, 4, 4,
54 	4, 4, 4, 4, 4, 4, 4, 4,
55 	1, 3, 1, 4, 4, 4, 4, 4,
56 	4, 4, 4, 4, 4, 1, 5, 5,
57 	5, 5, 5, 5, 5, 5, 5, 5,
58 	1, 6, 1, 7, 1, 1, 8, 8,
59 	8, 8, 8, 8, 8, 8, 8, 8,
60 	1, 8, 8, 8, 8, 8, 8, 8,
61 	8, 8, 8, 1, 5, 5, 5, 5,
62 	5, 5, 5, 5, 5, 5, 1, 1,
63 	1, 1, 1, 1, 1, 1, 1, 1,
64 	1, 9, 1, 1, 1, 1, 1, 1,
65 	1, 1, 1, 1, 1, 1, 1, 1,
66 	1, 1, 1, 1, 1, 1, 1, 1,
67 	1, 1, 1, 1, 1, 1, 1, 1,
68 	1, 9, 1, 8, 8, 8, 8, 8,
69 	8, 8, 8, 8, 8, 1, 3, 1,
70 	4, 4, 4, 4, 4, 4, 4, 4,
71 	4, 4, 1, 1, 1, 1, 1, 1,
72 	1, 1, 1, 1, 1, 9, 1, 1,
73 	1, 1, 1, 1, 1, 1, 1, 1,
74 	1, 1, 1, 1, 1, 1, 1, 1,
75 	1, 1, 1, 1, 1, 1, 1, 1,
76 	1, 1, 1, 1, 1, 9, 1, 0
77 };
78 
79 static const char _double_parser_trans_targs[] = {
80 	2, 0, 2, 3, 8, 6, 5, 5,
81 	7, 4
82 };
83 
84 static const char _double_parser_trans_actions[] = {
85 	0, 0, 1, 0, 2, 3, 0, 4,
86 	5, 0
87 };
88 
89 static const int double_parser_start = 1;
90 static const int double_parser_first_final = 6;
91 static const int double_parser_error = 0;
92 
93 static const int double_parser_en_main = 1;
94 
95 
96 #line 70 "hb-number-parser.rl"
97 
98 
99 /* Works only for n < 512 */
100 static inline double
_pow10(unsigned int exponent)101 _pow10 (unsigned int exponent)
102 {
103   static const double _powers_of_10[] =
104   {
105     1.0e+256,
106     1.0e+128,
107     1.0e+64,
108     1.0e+32,
109     1.0e+16,
110     1.0e+8,
111     10000.,
112     100.,
113     10.
114   };
115   unsigned int mask = 1 << (ARRAY_LENGTH (_powers_of_10) - 1);
116   double result = 1;
117   for (const double *power = _powers_of_10; mask; ++power, mask >>= 1)
118     if (exponent & mask) result *= *power;
119   return result;
120 }
121 
122 static inline double
strtod_rl(const char * buf,char ** end_ptr)123 strtod_rl (const char *buf, char **end_ptr)
124 {
125   const char *p, *pe;
126   double value = 0;
127   double frac = 0;
128   double frac_count = 0;
129   unsigned int exp = 0;
130   bool neg = false, exp_neg = false, exp_overflow = false;
131   const unsigned long long MAX_FRACT = 0xFFFFFFFFFFFFFull; /* 1^52-1 */
132   const unsigned int MAX_EXP = 0x7FFu; /* 1^11-1 */
133   p = buf;
134   pe = p + strlen (p);
135 
136   while (p < pe && ISSPACE (*p))
137     p++;
138 
139   int cs;
140 
141 #line 142 "hb-number-parser.hh"
142 	{
143 	cs = double_parser_start;
144 	}
145 
146 #line 147 "hb-number-parser.hh"
147 	{
148 	int _slen;
149 	int _trans;
150 	const unsigned char *_keys;
151 	const char *_inds;
152 	if ( p == pe )
153 		goto _test_eof;
154 	if ( cs == 0 )
155 		goto _out;
156 _resume:
157 	_keys = _double_parser_trans_keys + (cs<<1);
158 	_inds = _double_parser_indicies + _double_parser_index_offsets[cs];
159 
160 	_slen = _double_parser_key_spans[cs];
161 	_trans = _inds[ _slen > 0 && _keys[0] <=(*p) &&
162 		(*p) <= _keys[1] ?
163 		(*p) - _keys[0] : _slen ];
164 
165 	cs = _double_parser_trans_targs[_trans];
166 
167 	if ( _double_parser_trans_actions[_trans] == 0 )
168 		goto _again;
169 
170 	switch ( _double_parser_trans_actions[_trans] ) {
171 	case 1:
172 #line 39 "hb-number-parser.rl"
173 	{ neg = true; }
174 	break;
175 	case 4:
176 #line 40 "hb-number-parser.rl"
177 	{ exp_neg = true; }
178 	break;
179 	case 2:
180 #line 42 "hb-number-parser.rl"
181 	{
182 	value = value * 10. + ((*p) - '0');
183 }
184 	break;
185 	case 3:
186 #line 45 "hb-number-parser.rl"
187 	{
188 	if (likely (frac <= MAX_FRACT / 10))
189 	{
190 	  frac = frac * 10. + ((*p) - '0');
191 	  ++frac_count;
192 	}
193 }
194 	break;
195 	case 5:
196 #line 52 "hb-number-parser.rl"
197 	{
198 	if (likely (exp * 10 + ((*p) - '0') <= MAX_EXP))
199 	  exp = exp * 10 + ((*p) - '0');
200 	else
201 	  exp_overflow = true;
202 }
203 	break;
204 #line 205 "hb-number-parser.hh"
205 	}
206 
207 _again:
208 	if ( cs == 0 )
209 		goto _out;
210 	if ( ++p != pe )
211 		goto _resume;
212 	_test_eof: {}
213 	_out: {}
214 	}
215 
216 #line 116 "hb-number-parser.rl"
217 
218 
219   *end_ptr = (char *) p;
220 
221   if (frac_count) value += frac / _pow10 (frac_count);
222   if (neg) value *= -1.;
223 
224   if (unlikely (exp_overflow))
225   {
226     if (value == 0) return value;
227     if (exp_neg)    return neg ? -DBL_MIN : DBL_MIN;
228     else            return neg ? -DBL_MAX : DBL_MAX;
229   }
230 
231   if (exp)
232   {
233     if (exp_neg) value /= _pow10 (exp);
234     else         value *= _pow10 (exp);
235   }
236 
237   return value;
238 }
239 
240 #endif /* HB_NUMBER_PARSER_HH */
241