summaryrefslogtreecommitdiffstats
path: root/js/src/vm/make_unicode.py
blob: 5565d7d148cc00d67fc223b552eaca8e41e6e0ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Based upon makeunicodedata.py
# (http://hg.python.org/cpython/file/c8192197d23d/Tools/unicode/makeunicodedata.py)
# written by Fredrik Lundh (fredrik@pythonware.com)
#
#    Copyright (C) 2011 Tom Schuster <evilpies@gmail.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

from __future__ import print_function
import csv
import io
import re
import os
import sys
from contextlib import closing

# ECMAScript 2016
# §11.2 White Space
whitespace = [
    # python doesn't support using control character names :(
    0x9, # CHARACTER TABULATION
    0xb, # LINE TABULATION
    0xc, # FORM FEED
    ord(u'\N{SPACE}'),
    ord(u'\N{NO-BREAK SPACE}'),
    ord(u'\N{ZERO WIDTH NO-BREAK SPACE}'), # also BOM
]

# §11.3 Line Terminators
line_terminator = [
    0xa, # LINE FEED
    0xd, # CARRIAGE RETURN
    ord(u'\N{LINE SEPARATOR}'),
    ord(u'\N{PARAGRAPH SEPARATOR}'),
]

# These are also part of IdentifierPart §11.6 Names and Keywords
compatibility_identifier_part = [
    ord(u'\N{ZERO WIDTH NON-JOINER}'),
    ord(u'\N{ZERO WIDTH JOINER}'),
]

FLAG_SPACE = 1 << 0
FLAG_UNICODE_ID_START = 1 << 1
FLAG_UNICODE_ID_CONTINUE_ONLY = 1 << 2

MAX_BMP = 0xffff

public_domain = """
/*
 * Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/licenses/publicdomain/
 */
"""

mpl_license = """\
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
"""

warning_message = """\
/* Generated by make_unicode.py DO NOT MODIFY */
"""

unicode_version_message = """\
/* Unicode version: {0} */
"""

def read_unicode_data(unicode_data):
    """
        If you want to understand how this wonderful file format works checkout
          Unicode Standard Annex #44 - Unicode Character Database
          http://www.unicode.org/reports/tr44/
    """

    reader = csv.reader(unicode_data, delimiter=';')

    while True:
        row = reader.next()
        name = row[1]

        # We need to expand the UAX #44 4.2.3 Code Point Range
        if name.startswith('<') and name.endswith('First>'):
            next_row = reader.next()

            for i in range(int(row[0], 16), int(next_row[0], 16) + 1):
                row[0] = i
                row[1] = name[1:-8]

                yield row
        else:
            row[0] = int(row[0], 16)
            yield row

def read_case_folding(case_folding):
    for line in case_folding:
        if line == '\n' or line.startswith('#'):
            continue
        row = line.split('; ')
        if row[1] in ['F', 'T']:
            continue
        row[0] = int(row[0], 16)
        row[2] = int(row[2], 16)
        yield row

def read_derived_core_properties(derived_core_properties):
    for line in derived_core_properties:
        if line == '\n' or line.startswith('#'):
            continue
        row = line.split('#')[0].split(';')
        char_range = row[0].strip()
        char_property = row[1].strip()
        if '..' not in char_range:
            yield (int(char_range, 16), char_property)
        else:
            [start, end] = char_range.split('..')
            for char in range(int(start, 16), int(end, 16) + 1):
                yield (char, char_property)

def utf16_encode(code):
    NonBMPMin = 0x10000
    LeadSurrogateMin = 0xD800
    TrailSurrogateMin = 0xDC00

    lead = (code - NonBMPMin) / 1024 + LeadSurrogateMin
    trail = ((code - NonBMPMin) % 1024) + TrailSurrogateMin

    return lead, trail

def make_non_bmp_convert_macro(out_file, name, convert_map):
    convert_list = []
    entry = None
    for code in sorted(convert_map.keys()):
        converted = convert_map[code]
        diff = converted - code

        if entry and code == entry['code'] + entry['length'] and diff == entry['diff']:
            entry['length'] += 1
            continue

        entry = { 'code': code, 'diff': diff, 'length': 1 }
        convert_list.append(entry)

    lines = []
    for entry in convert_list:
        from_code = entry['code']
        to_code = entry['code'] + entry['length'] - 1
        diff = entry['diff']

        from_lead, from_trail = utf16_encode(from_code)
        to_lead, to_trail = utf16_encode(to_code)

        assert from_lead == to_lead

        lines.append('    macro(0x{:x}, 0x{:x}, 0x{:x}, 0x{:x}, 0x{:x}, {:d})'.format(
            from_code, to_code, from_lead, from_trail, to_trail, diff))

    out_file.write('#define FOR_EACH_NON_BMP_{}(macro) \\\n'.format(name))
    out_file.write(' \\\n'.join(lines))
    out_file.write('\n')

def process_derived_core_properties(derived_core_properties):
    id_start = set()
    id_continue = set()

    for (char, prop) in read_derived_core_properties(derived_core_properties):
        if prop == 'ID_Start':
            id_start.add(char)
        if prop == 'ID_Continue':
            id_continue.add(char)

    return (id_start, id_continue)

def process_unicode_data(unicode_data, derived_core_properties):
    dummy = (0, 0, 0)
    table = [dummy]
    cache = {dummy: 0}
    index = [0] * (MAX_BMP + 1)
    same_upper_map = {}
    same_upper_dummy = (0, 0, 0)
    same_upper_table = [same_upper_dummy]
    same_upper_cache = {same_upper_dummy: 0}
    same_upper_index = [0] * (MAX_BMP + 1)

    test_table = {}
    test_space_table = []

    non_bmp_lower_map = {}
    non_bmp_upper_map = {}

    (id_start, id_continue) = process_derived_core_properties(derived_core_properties)

    for row in read_unicode_data(unicode_data):
        code = row[0]
        name = row[1]
        category = row[2]
        alias = row[-5]
        uppercase = row[-3]
        lowercase = row[-2]
        flags = 0

        if uppercase:
            upper = int(uppercase, 16)

            if upper not in same_upper_map:
                same_upper_map[upper] = [code]
            else:
                same_upper_map[upper].append(code)
        else:
            upper = code

        if lowercase:
            lower = int(lowercase, 16)
        else:
            lower = code

        if code > MAX_BMP:
            if code != lower:
                non_bmp_lower_map[code] = lower
            if code != upper:
                non_bmp_upper_map[code] = upper
            continue

        # we combine whitespace and lineterminators because in pratice we don't need them separated
        if category == 'Zs' or code in whitespace or code in line_terminator:
            flags |= FLAG_SPACE
            test_space_table.append(code)

        # §11.6 (IdentifierStart)
        if code in id_start:
            flags |= FLAG_UNICODE_ID_START

        # §11.6 (IdentifierPart)
        elif code in id_continue or code in compatibility_identifier_part:
            flags |= FLAG_UNICODE_ID_CONTINUE_ONLY

        test_table[code] = (upper, lower, name, alias)

        up_d = upper - code
        low_d = lower - code

        assert up_d > -65535 and up_d < 65535
        assert low_d > -65535 and low_d < 65535

        upper = up_d & 0xffff
        lower = low_d & 0xffff

        item = (upper, lower, flags)

        i = cache.get(item)
        if i is None:
            assert item not in table
            cache[item] = i = len(table)
            table.append(item)
        index[code] = i

    for code in range(0, MAX_BMP + 1):
        entry = test_table.get(code)

        if not entry:
            continue

        (upper, lower, name, alias) = entry

        if upper not in same_upper_map:
            continue

        same_upper_ds = [v - code for v in same_upper_map[upper]]

        assert len(same_upper_ds) <= 3
        assert all([v > -65535 and v < 65535 for v in same_upper_ds])

        same_upper = [v & 0xffff for v in same_upper_ds]
        same_upper_0 = same_upper[0] if len(same_upper) >= 1 else 0
        same_upper_1 = same_upper[1] if len(same_upper) >= 2 else 0
        same_upper_2 = same_upper[2] if len(same_upper) >= 3 else 0

        item = (same_upper_0, same_upper_1, same_upper_2)

        i = same_upper_cache.get(item)
        if i is None:
            assert item not in same_upper_table
            same_upper_cache[item] = i = len(same_upper_table)
            same_upper_table.append(item)
        same_upper_index[code] = i

    return (
        table, index,
        same_upper_table, same_upper_index,
        non_bmp_lower_map, non_bmp_upper_map,
        test_table, test_space_table,
    )

def process_case_folding(case_folding):
    folding_map = {}
    rev_folding_map = {}
    folding_dummy = (0, 0, 0, 0)
    folding_table = [folding_dummy]
    folding_cache = {folding_dummy: 0}
    folding_index = [0] * (MAX_BMP + 1)

    folding_tests = []
    folding_codes = set()

    non_bmp_folding_map = {}
    non_bmp_rev_folding_map = {}

    for row in read_case_folding(case_folding):
        code = row[0]
        mapping = row[2]
        folding_map[code] = mapping

        if code > MAX_BMP:
            non_bmp_folding_map[code] = mapping
            non_bmp_rev_folding_map[mapping] = code

        if mapping not in rev_folding_map:
            rev_folding_map[mapping] = [code]
        else:
            rev_folding_map[mapping].append(code)

        folding_codes.add(code)
        folding_codes.add(mapping)

    for code in sorted(folding_codes):
        if code in folding_map:
            folding = folding_map[code]
        else:
            folding = code

        if code in rev_folding_map:
            rev_folding = rev_folding_map[code]
        elif folding in rev_folding_map:
            rev_folding = [c for c in rev_folding_map[folding] if c != code]
        else:
            rev_folding = []

        assert len(rev_folding) <= 3

        if folding != code or len(rev_folding):
            item = [code]
            if folding != code:
                item.append(folding)
            folding_tests.append(item + rev_folding)

        if code > MAX_BMP:
            continue

        folding_d = folding - code
        rev_folding_ds = [v - code for v in rev_folding]

        assert folding_d > -65535 and folding_d < 65535
        assert all([v > -65535 and v < 65535 for v in rev_folding])

        folding = folding_d & 0xffff
        rev_folding = [v & 0xffff for v in rev_folding_ds]
        rev_folding_0 = rev_folding[0] if len(rev_folding) >= 1 else 0
        rev_folding_1 = rev_folding[1] if len(rev_folding) >= 2 else 0
        rev_folding_2 = rev_folding[2] if len(rev_folding) >= 3 else 0

        item = (folding, rev_folding_0, rev_folding_1, rev_folding_2)

        i = folding_cache.get(item)
        if i is None:
            assert item not in folding_table
            folding_cache[item] = i = len(folding_table)
            folding_table.append(item)
        folding_index[code] = i
    return (
        folding_table, folding_index,
        non_bmp_folding_map, non_bmp_rev_folding_map,
        folding_tests
    )

def make_non_bmp_file(version,
                      non_bmp_lower_map, non_bmp_upper_map,
                      non_bmp_folding_map, non_bmp_rev_folding_map):
    file_name = 'UnicodeNonBMP.h';
    with io.open(file_name, mode='wb') as non_bmp_file:
        non_bmp_file.write(mpl_license)
        non_bmp_file.write('\n')
        non_bmp_file.write(warning_message)
        non_bmp_file.write(unicode_version_message.format(version))
        non_bmp_file.write("""
#ifndef vm_UnicodeNonBMP_h
#define vm_UnicodeNonBMP_h

""")

        make_non_bmp_convert_macro(non_bmp_file, 'LOWERCASE', non_bmp_lower_map)
        non_bmp_file.write('\n')
        make_non_bmp_convert_macro(non_bmp_file, 'UPPERCASE', non_bmp_upper_map)
        non_bmp_file.write('\n')
        make_non_bmp_convert_macro(non_bmp_file, 'CASE_FOLDING', non_bmp_folding_map)
        non_bmp_file.write('\n')
        make_non_bmp_convert_macro(non_bmp_file, 'REV_CASE_FOLDING', non_bmp_rev_folding_map)

        non_bmp_file.write("""
#endif /* vm_UnicodeNonBMP_h */
""")

def make_bmp_mapping_test(version, test_table):
    file_name = '../tests/ecma_5/String/string-upper-lower-mapping.js'
    with io.open(file_name, mode='wb') as test_mapping:
        test_mapping.write(warning_message)
        test_mapping.write(unicode_version_message.format(version))
        test_mapping.write(public_domain)
        test_mapping.write('var mapping = [\n')
        for code in range(0, MAX_BMP + 1):
            entry = test_table.get(code)

            if entry:
                (upper, lower, name, alias) = entry
                test_mapping.write('  [' + hex(upper) + ', ' + hex(lower) + '], /* ' +
                        name + (' (' + alias + ')' if alias else '') + ' */\n')
            else:
                test_mapping.write('  [' + hex(code) + ', ' + hex(code) + '],\n')
        test_mapping.write('];')
        test_mapping.write("""
assertEq(mapping.length, 0x10000);
for (var i = 0; i <= 0xffff; i++) {
    var char = String.fromCharCode(i);
    var info = mapping[i];

    assertEq(char.toUpperCase().charCodeAt(0), info[0]);
    assertEq(char.toLowerCase().charCodeAt(0), info[1]);
}

if (typeof reportCompare === "function")
    reportCompare(true, true);
""")

def make_non_bmp_mapping_test(version, non_bmp_upper_map, non_bmp_lower_map):
    file_name = '../tests/ecma_6/String/string-code-point-upper-lower-mapping.js'
    with io.open(file_name, mode='wb') as test_non_bmp_mapping:
        test_non_bmp_mapping.write(warning_message)
        test_non_bmp_mapping.write(unicode_version_message.format(version))
        test_non_bmp_mapping.write(public_domain)
        for code in sorted(non_bmp_upper_map.keys()):
            test_non_bmp_mapping.write("""\
assertEq(String.fromCodePoint(0x{:x}).toUpperCase().codePointAt(0), 0x{:x});
""".format(code, non_bmp_upper_map[code]))
        for code in sorted(non_bmp_lower_map.keys()):
            test_non_bmp_mapping.write("""\
assertEq(String.fromCodePoint(0x{:x}).toLowerCase().codePointAt(0), 0x{:x});
""".format(code, non_bmp_lower_map[code]))

        test_non_bmp_mapping.write("""
if (typeof reportCompare === "function")
    reportCompare(true, true);
""")

def make_space_test(version, test_space_table):
    file_name = '../tests/ecma_5/String/string-space-trim.js'
    with io.open(file_name, mode='wb') as test_space:
        test_space.write(warning_message)
        test_space.write(unicode_version_message.format(version))
        test_space.write(public_domain)
        test_space.write('var onlySpace = String.fromCharCode(' +
                        ', '.join(map(lambda c: hex(c), test_space_table)) + ');\n')
        test_space.write("""
assertEq(onlySpace.trim(), "");
assertEq((onlySpace + 'aaaa').trim(), 'aaaa');
assertEq(('aaaa' + onlySpace).trim(), 'aaaa');
assertEq((onlySpace + 'aaaa' + onlySpace).trim(), 'aaaa');

if (typeof reportCompare === "function")
    reportCompare(true, true);
""")

def make_icase_test(version, folding_tests):
    file_name = '../tests/ecma_6/RegExp/unicode-ignoreCase.js'
    with io.open(file_name, mode='wb') as test_icase:
        test_icase.write(warning_message)
        test_icase.write(unicode_version_message.format(version))
        test_icase.write(public_domain)
        test_icase.write("""
var BUGNUMBER = 1135377;
var summary = "Implement RegExp unicode flag -- ignoreCase flag.";

print(BUGNUMBER + ": " + summary);

function test(code, ...equivs) {
  var codeRe = new RegExp(String.fromCodePoint(code) + "+", "iu");
  var ans = String.fromCodePoint(code) + equivs.map(c => String.fromCodePoint(c)).join("");
  assertEqArray(codeRe.exec("<" + ans + ">"), [ans]);
  codeRe = new RegExp("[" + String.fromCodePoint(code) + "]+", "iu");
  assertEqArray(codeRe.exec("<" + ans + ">"), [ans]);
}
""")
        for args in folding_tests:
            test_icase.write('test(' + ','.join([hex(c) for c in args]) + ');\n')
        test_icase.write("""
if (typeof reportCompare === "function")
    reportCompare(true, true);
""")

def make_unicode_file(version,
                      table, index,
                      same_upper_table, same_upper_index,
                      folding_table, folding_index):
    index1, index2, shift = splitbins(index)

    # Don't forget to update CharInfo in Unicode.h if you need to change this
    assert shift == 6

    same_upper_index1, same_upper_index2, same_upper_shift = splitbins(same_upper_index)

    # Don't forget to update CodepointsWithSameUpperCaseInfo in Unicode.h if you need to change this
    assert same_upper_shift == 6

    folding_index1, folding_index2, folding_shift = splitbins(folding_index)

    # Don't forget to update CaseFoldInfo in Unicode.h if you need to change this
    assert folding_shift == 6

    # verify correctness
    for char in index:
        test = table[index[char]]

        idx = index1[char >> shift]
        idx = index2[(idx << shift) + (char & ((1 << shift) - 1))]

        assert test == table[idx]

    # verify correctness
    for char in same_upper_index:
        test = same_upper_table[same_upper_index[char]]

        idx = same_upper_index1[char >> same_upper_shift]
        idx = same_upper_index2[(idx << same_upper_shift) + (char & ((1 << same_upper_shift) - 1))]

        assert test == same_upper_table[idx]

    # verify correctness
    for char in folding_index:
        test = folding_table[folding_index[char]]

        idx = folding_index1[char >> folding_shift]
        idx = folding_index2[(idx << folding_shift) + (char & ((1 << folding_shift) - 1))]

        assert test == folding_table[idx]

    comment = """
/*
 * So how does indexing work?
 * First let's have a look at a char16_t, 16-bits:
 *              [................]
 * Step 1:
 *  Extracting the upper 11 bits from the char16_t.
 *   upper = char >>  5 ([***********.....])
 * Step 2:
 *  Using these bits to get an reduced index from index1.
 *   index = index1[upper]
 * Step 3:
 *  Combining the index and the bottom 5 bits of the original char16_t.
 *   real_index = index2[(index << 5) + (char & ((1 << 5) - 1))] ([...********+++++])
 *
 * The advantage here is that the biggest number in index1 doesn't need 10 bits,
 * but 7 and we save some memory.
 *
 * Step 4:
 *  Get the character informations by looking up real_index in js_charinfo.
 *
 * Pseudocode of generation:
 *
 * let table be the mapping of char16_t => js_charinfo_index
 * let index1 be an empty array
 * let index2 be an empty array
 * let cache be a hash map
 *
 * while shift is less then maximal amount you can shift 0xffff before it's 0
 *  let chunks be table split in chunks of size 2**shift
 *
 *  for every chunk in chunks
 *   if chunk is in cache
 *    let index be cache[chunk]
 *   else
 *    let index be the max key of index2 + 1
 *    for element in chunk
 *     push element to index2
 *    put index as chunk in cache
 *
 *   push index >> shift to index1
 *
 *  increase shift
 *  stop if you found the best shift
 */
"""
    def dump(data, name, file):
        file.write('const uint8_t unicode::' + name + '[] = {\n')

        line = pad = ' ' * 4
        lines = []
        for entry in data:
            assert entry < 256
            s = str(entry)
            s = s.rjust(3)

            if len(line + s) + 5 > 99:
                lines.append(line.rstrip())
                line = pad + s + ', '
            else:
                line = line + s + ', '
        lines.append(line.rstrip())

        file.write('\n'.join(lines))
        file.write('\n};\n')

    file_name = 'Unicode.cpp'
    with io.open(file_name, 'wb') as data_file:
        data_file.write(warning_message)
        data_file.write(unicode_version_message.format(version))
        data_file.write(public_domain)
        data_file.write('#include "vm/Unicode.h"\n\n')
        data_file.write('using namespace js;\n')
        data_file.write('using namespace js::unicode;\n')
        data_file.write(comment)
        data_file.write('const CharacterInfo unicode::js_charinfo[] = {\n')
        for d in table:
            data_file.write('    {')
            data_file.write(', '.join((str(e) for e in d)))
            data_file.write('},\n')
        data_file.write('};\n')
        data_file.write('\n')

        dump(index1, 'index1', data_file)
        data_file.write('\n')
        dump(index2, 'index2', data_file)
        data_file.write('\n')

        data_file.write('const CodepointsWithSameUpperCaseInfo unicode::js_codepoints_with_same_upper_info[] = {\n')
        for d in same_upper_table:
            data_file.write('    {')
            data_file.write(', '.join((str(e) for e in d)))
            data_file.write('},\n')
        data_file.write('};\n')
        data_file.write('\n')

        dump(same_upper_index1, 'codepoints_with_same_upper_index1', data_file)
        data_file.write('\n')
        dump(same_upper_index2, 'codepoints_with_same_upper_index2', data_file)
        data_file.write('\n')

        data_file.write('const FoldingInfo unicode::js_foldinfo[] = {\n')
        for d in folding_table:
            data_file.write('    {')
            data_file.write(', '.join((str(e) for e in d)))
            data_file.write('},\n')
        data_file.write('};\n')
        data_file.write('\n')

        dump(folding_index1, 'folding_index1', data_file)
        data_file.write('\n')
        dump(folding_index2, 'folding_index2', data_file)
        data_file.write('\n')

def getsize(data):
    """ return smallest possible integer size for the given array """
    maxdata = max(data)
    assert maxdata < 2**32

    if maxdata < 256:
        return 1
    elif maxdata < 65536:
        return 2
    else:
        return 4

def splitbins(t):
    """t -> (t1, t2, shift).  Split a table to save space.

    t is a sequence of ints.  This function can be useful to save space if
    many of the ints are the same.  t1 and t2 are lists of ints, and shift
    is an int, chosen to minimize the combined size of t1 and t2 (in C
    code), and where for each i in range(len(t)),
        t[i] == t2[(t1[i >> shift] << shift) + (i & mask)]
    where mask is a bitmask isolating the last "shift" bits.
    """

    def dump(t1, t2, shift, bytes):
        print("%d+%d bins at shift %d; %d bytes" % (
            len(t1), len(t2), shift, bytes), file=sys.stderr)
        print("Size of original table:", len(t)*getsize(t), \
            "bytes", file=sys.stderr)
    n = len(t)-1    # last valid index
    maxshift = 0    # the most we can shift n and still have something left
    if n > 0:
        while n >> 1:
            n >>= 1
            maxshift += 1
    del n
    bytes = sys.maxsize  # smallest total size so far
    t = tuple(t)    # so slices can be dict keys
    for shift in range(maxshift + 1):
        t1 = []
        t2 = []
        size = 2**shift
        bincache = {}

        for i in range(0, len(t), size):
            bin = t[i:i + size]

            index = bincache.get(bin)
            if index is None:
                index = len(t2)
                bincache[bin] = index
                t2.extend(bin)
            t1.append(index >> shift)

        # determine memory size
        b = len(t1) * getsize(t1) + len(t2) * getsize(t2)
        if b < bytes:
            best = t1, t2, shift
            bytes = b
    t1, t2, shift = best

    print("Best:", end=' ', file=sys.stderr)
    dump(t1, t2, shift, bytes)

    # exhaustively verify that the decomposition is correct
    mask = 2**shift - 1
    for i in range(len(t)):
        assert t[i] == t2[(t1[i >> shift] << shift) + (i & mask)]
    return best

def update_unicode(args):
    import urllib2

    version = args.version
    if version is not None:
        baseurl = 'http://unicode.org/Public'
        if version == 'UNIDATA':
            url = '%s/%s' % (baseurl, version)
        else:
            url = '%s/%s/ucd' % (baseurl, version)

    print('Arguments:')
    if version is not None:
        print('\tVersion: %s' % version)
        print('\tDownload url: %s' % url)
    else:
        print('\tUsing local files.')
        print('\tAlways make sure you have the newest Unicode files!')
    print('')

    def download_or_open(fname):
        tfile_path = os.path.join(os.getcwd(), fname)
        if version is not None:
            print('Downloading %s...' % fname)
            unicode_data_url = '%s/%s' % (url, fname)
            with closing(urllib2.urlopen(unicode_data_url)) as reader:
                data = reader.read()
            tfile = io.open(tfile_path, 'w+b')
            tfile.write(data)
            tfile.flush()
            tfile.seek(0)
        else:
            if not os.path.isfile(tfile_path):
                raise RuntimeError('File not found: %s' % tfile_path)
            tfile = io.open(tfile_path, 'rb');
        return tfile

    def version_from_file(f, fname):
        pat_version = re.compile(r"# %s-(?P<version>\d+\.\d+\.\d+).txt" % fname)
        return pat_version.match(f.readline()).group("version")

    with download_or_open('UnicodeData.txt') as unicode_data, \
         download_or_open('CaseFolding.txt') as case_folding, \
         download_or_open('DerivedCoreProperties.txt') as derived_core_properties:
        unicode_version = version_from_file(derived_core_properties, 'DerivedCoreProperties')

        print('Processing...')
        (
            table, index,
            same_upper_table, same_upper_index,
            non_bmp_lower_map, non_bmp_upper_map,
            test_table, test_space_table
        ) = process_unicode_data(unicode_data, derived_core_properties)
        (
            folding_table, folding_index,
            non_bmp_folding_map, non_bmp_rev_folding_map,
            folding_tests
        ) = process_case_folding(case_folding)

    print('Generating...')
    make_unicode_file(unicode_version,
                      table, index,
                      same_upper_table, same_upper_index,
                      folding_table, folding_index)
    make_non_bmp_file(unicode_version,
                      non_bmp_lower_map, non_bmp_upper_map,
                      non_bmp_folding_map, non_bmp_rev_folding_map)

    make_bmp_mapping_test(unicode_version, test_table)
    make_non_bmp_mapping_test(unicode_version, non_bmp_upper_map, non_bmp_lower_map)
    make_space_test(unicode_version, test_space_table)
    make_icase_test(unicode_version, folding_tests)

if __name__ == '__main__':
    import argparse

    # This script must be run from js/src/vm to work correctly.
    if '/'.join(os.path.normpath(os.getcwd()).split(os.sep)[-3:]) != 'js/src/vm':
        raise RuntimeError('%s must be run from js/src/vm' % sys.argv[0])

    parser = argparse.ArgumentParser(description='Update Unicode data.')

    parser.add_argument('--version',
                        help='Optional Unicode version number. If specified, downloads the\
                              selected version from <http://unicode.org/Public>. If not specified\
                              uses the existing local files to generate the Unicode data. The\
                              number must match a published Unicode version, e.g. use\
                              "--version=8.0.0" to download Unicode 8 files. Alternatively use\
                              "--version=UNIDATA" to download the latest published version.')

    parser.set_defaults(func=update_unicode)

    args = parser.parse_args()
    args.func(args)