File: gen_dispatch.py

package info (click to toggle)
libepoxy 1.2-1
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-kfreebsd
  • size: 3,028 kB
  • ctags: 312
  • sloc: xml: 46,840; ansic: 2,439; python: 550; makefile: 283; sh: 9
file content (837 lines) | stat: -rwxr-xr-x 35,969 bytes parent folder | download
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
837
#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright © 2013 Intel Corporation
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice (including the next
# paragraph) shall be included in all copies or substantial portions of the
# Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

import sys
import argparse
import xml.etree.ElementTree as ET
import re
import os

class GLProvider(object):
    def __init__(self, condition, condition_name, loader, name):
        # C code for determining if this function is available.
        # (e.g. epoxy_is_desktop_gl() && epoxy_gl_version() >= 20
        self.condition = condition

        # A string (possibly with spaces) describing the condition.
        self.condition_name = condition_name

        # The loader for getting the symbol -- either dlsym or
        # getprocaddress.  This is a python format string to generate
        # C code, given self.name.
        self.loader = loader

        # The name of the function to be loaded (possibly an
        # ARB/EXT/whatever-decorated variant).
        self.name = name

        # This is the C enum name we'll use for referring to this provider.
        self.enum = condition_name
        self.enum = self.enum.replace(' ', '_')
        self.enum = self.enum.replace('\\"', '')
        self.enum = self.enum.replace('.', '_')

class GLFunction(object):
    def __init__(self, ret_type, name):
        self.name = name
        self.ptr_type = 'PFN' + name.upper() + 'PROC'
        self.ret_type = ret_type
        self.providers = {}
        self.args = []

        # These are functions with hand-written wrapper code in
        # dispatch_common.c.  Their dispatch entries are replaced with
        # non-public symbols with a "_unwrapped" suffix.
        wrapped_functions = {
            'glBegin',
            'glEnd',
            'wglMakeCurrent',
            'wglMakeContextCurrentEXT',
            'wglMakeContextCurrentARB',
            'wglMakeAssociatedContextCurrentAMD',
        }

        if name in wrapped_functions:
            self.wrapped_name = name + '_unwrapped'
            self.public = ''
        else:
            self.wrapped_name = name
            self.public = 'PUBLIC '

        # This is the string of C code for passing through the
        # arguments to the function.
        self.args_list = ''

        # This is the string of C code for declaring the arguments
        # list.
        self.args_decl = 'void'

        # This is the string name of the function that this is an
        # alias of, or self.name.  This initially comes from the
        # registry, and may get updated if it turns out our alias is
        # itself an alias (for example glFramebufferTextureEXT ->
        # glFramebufferTextureARB -> glFramebufferTexture)
        self.alias_name = name

        # After alias resolution, this is the function that this is an
        # alias of.
        self.alias_func = None

        # For the root of an alias tree, this lists the functions that
        # are marked as aliases of it, so that it can write a resolver
        # for all of them.
        self.alias_exts = []

    def add_arg(self, type, name):
        # Reword glDepthRange() arguments to avoid clashing with the
        # "near" and "far" keywords on win32.
        if name == "near":
            name = "hither"
        elif name == "far":
            name = "yon"

        # Mac screwed up GLhandleARB and made it a void * instead of
        # uint32_t, despite it being specced as only necessarily 32
        # bits wide, causing portability problems all over.  There are
        # prototype conflicts between things like
        # glAttachShader(GLuint program, GLuint shader) and
        # glAttachObjectARB(GLhandleARB container, GLhandleARB obj),
        # even though they are marked as aliases in the XML (and being
        # aliases in Mesa).
        #
        # We retain those aliases.  In the x86_64 ABI, the first 6
        # args are stored in 64-bit registers, so the calls end up
        # being the same despite the different types.  We just need to
        # add a cast to uintptr_t to shut up the compiler.
        if type == 'GLhandleARB':
            assert(len(self.args) < 6)
            arg_list_name = '(uintptr_t)' + name
        else:
            arg_list_name = name

        self.args.append((type, name))
        if self.args_decl == 'void':
            self.args_list = arg_list_name
            self.args_decl = type + ' ' + name
        else:
            self.args_list += ', ' + arg_list_name
            self.args_decl += ', ' + type + ' ' + name

    def add_provider(self, condition, loader, condition_name):
        self.providers[condition_name] = GLProvider(condition, condition_name,
                                                    loader, self.name)

    def add_alias(self, ext):
        assert self.alias_func is None

        self.alias_exts.append(ext)
        ext.alias_func = self

class Generator(object):
    def __init__(self, target):
        self.target = target
        self.enums = {}
        self.functions = {}
        self.sorted_function = None
        self.max_enum_name_len = 1
        self.copyright_comment = None
        self.typedefs = ''
        self.out_file = None

        # GL versions named in the registry, which we should generate
        # #defines for.
        self.supported_versions = set()

        # Extensions named in the registry, which we should generate
        # #defines for.
        self.supported_extensions = set()

        # Dictionary mapping human-readable names of providers to a C
        # enum token that will be used to reference those names, to
        # reduce generated binary size.
        self.provider_enum = {}

        # Dictionary mapping human-readable names of providers to C
        # code to detect if it's present.
        self.provider_condition = {}

        # Dictionary mapping human-readable names of providers to
        # format strings for fetching the function pointer when
        # provided the name of the symbol to be requested.
        self.provider_loader = {}

    def all_text_until_element_name(self, element, element_name):
        text = ''

        if element.text is not None:
            text += element.text

        for child in element:
            if child.tag == element_name:
                break
            if child.text:
                text += child.text
            if child.tail:
                text += child.tail
        return text

    def out(self, text):
        self.out_file.write(text)

    def outln(self, text):
        self.out_file.write(text + '\n')

    def parse_typedefs(self, reg):
        for t in reg.findall('types/type'):
            if 'name' in t.attrib and t.attrib['name'] not in {'GLhandleARB'}:
                continue

            # The gles1/gles2-specific types are redundant
            # declarations, and the different types used for them (int
            # vs int32_t) caused problems on win32 builds.
            api = t.get('api')
            if api:
                continue

            if t.text is not None:
                self.typedefs += t.text

            for child in t:
                if child.text:
                    self.typedefs += child.text
                if child.tail:
                    self.typedefs += child.tail
            self.typedefs += '\n'

    def parse_enums(self, reg):
        for enum in reg.findall('enums/enum'):
            name = enum.get('name')

            # wgl.xml's 0xwhatever definitions end up colliding with
            # wingdi.h's decimal definitions of these.
            if ('WGL_SWAP_OVERLAY' in name or
                'WGL_SWAP_UNDERLAY' in name or
                'WGL_SWAP_MAIN_PLANE' in name):
                continue

            self.max_enum_name_len = max(self.max_enum_name_len, len(name))
            self.enums[name] = enum.get('value')

    def get_function_return_type(self, proto):
        # Everything up to the start of the name element is the return type.
        return self.all_text_until_element_name(proto, 'name').strip()

    def parse_function_definitions(self, reg):
        for command in reg.findall('commands/command'):
            proto = command.find('proto')
            name = proto.find('name').text
            ret_type = self.get_function_return_type(proto)

            func = GLFunction(ret_type, name)

            for arg in command.findall('param'):
                func.add_arg(self.all_text_until_element_name(arg, 'name').strip(),
                             arg.find('name').text)

            alias = command.find('alias')
            if alias is not None:
                # Note that some alias references appear before the
                # target command is defined (glAttachObjectARB() ->
                # glAttachShader(), for example).
                func.alias_name = alias.get('name')

            self.functions[name] = func

    def drop_weird_glx_functions(self):
        # Drop a few ancient SGIX GLX extensions that use types not defined
        # anywhere in Xlib.  In glxext.h, they're protected by #ifdefs for the
        # headers that defined them.
        weird_functions = [name for name, func in self.functions.items()
                           if 'VLServer' in func.args_decl
                           or 'DMparams' in func.args_decl]

        for name in weird_functions:
            del self.functions[name]

    def resolve_aliases(self):
        for func in self.functions.values():
            # Find the root of the alias tree, and add ourselves to it.
            if func.alias_name != func.name:
                alias_func = func
                while alias_func.alias_name != alias_func.name:
                    alias_func = self.functions[alias_func.alias_name]
                func.alias_name = alias_func.name
                func.alias_func = alias_func
                alias_func.alias_exts.append(func)

    def prepare_provider_enum(self):
        self.provider_enum = {}

        # We assume that for any given provider, all functions using
        # it will have the same loader.  This lets us generate a
        # general C function for detecting conditions and calling the
        # dlsym/getprocaddress, and have our many resolver stubs just
        # call it with a table of values.
        for func in self.functions.values():
            for provider in func.providers.values():
                if provider.condition_name in self.provider_enum:
                    assert(self.provider_condition[provider.condition_name] == provider.condition)
                    assert(self.provider_loader[provider.condition_name] == provider.loader)
                    continue

                self.provider_enum[provider.condition_name] = provider.enum;
                self.provider_condition[provider.condition_name] = provider.condition;
                self.provider_loader[provider.condition_name] = provider.loader;

    def sort_functions(self):
        self.sorted_functions = sorted(self.functions.values(), key=lambda func:func.name)

    def process_require_statements(self, feature, condition, loader, human_name):
        for command in feature.findall('require/command'):
            name = command.get('name')

            # wgl.xml describes 6 functions in WGL 1.0 that are in
            # gdi32.dll instead of opengl32.dll, and we would need to
            # change up our symbol loading to support that.  Just
            # don't wrap those functions.
            if self.target == 'wgl' and 'wgl' not in name:
                del self.functions[name]
                continue;

            func = self.functions[name]
            func.add_provider(condition, loader, human_name)

    def parse_function_providers(self, reg):
        for feature in reg.findall('feature'):
            api = feature.get('api') # string gl, gles1, gles2, glx
            m = re.match('([0-9])\.([0-9])', feature.get('number'))
            version = int(m.group(1)) * 10 + int(m.group(2))

            self.supported_versions.add(feature.get('name'))

            if api == 'gl':
                human_name = 'Desktop OpenGL {0}'.format(feature.get('number'))
                condition = 'epoxy_is_desktop_gl()'

                loader = 'epoxy_get_core_proc_address({0}, {1})'.format('{0}', version)
                if version >= 11:
                    condition += ' && epoxy_conservative_gl_version() >= {0}'.format(version)
            elif api == 'gles2':
                human_name = 'OpenGL ES {0}'.format(feature.get('number'))
                condition = '!epoxy_is_desktop_gl() && epoxy_gl_version() >= {0}'.format(version)

                if version <= 20:
                    loader = 'epoxy_gles2_dlsym({0})'
                else:
                    loader = 'epoxy_gles3_dlsym({0})'
            elif api == 'gles1':
                human_name = 'OpenGL ES 1.0'
                condition = '!epoxy_is_desktop_gl() && epoxy_gl_version() >= 10 && epoxy_gl_version() < 20'
                loader = 'epoxy_gles1_dlsym({0})'
            elif api == 'glx':
                human_name = 'GLX {0}'.format(version)
                # We could just always use GPA for loading everything
                # but glXGetProcAddress(), but dlsym() is a more
                # efficient lookup.
                if version > 13:
                    condition = 'epoxy_conservative_glx_version() >= {0}'.format(version)
                    loader = 'glXGetProcAddress((const GLubyte *){0})'
                else:
                    condition = 'true'
                    loader = 'epoxy_glx_dlsym({0})'
            elif api == 'egl':
                human_name = 'EGL {0}'.format(version)
                if version > 10:
                    condition = 'epoxy_conservative_egl_version() >= {0}'.format(version)
                else:
                    condition = 'true'
                # All EGL core entrypoints must be dlsym()ed out --
                # eglGetProcAdddress() will return NULL.
                loader = 'epoxy_egl_dlsym({0})'
            elif api == 'wgl':
                human_name = 'WGL {0}'.format(version)
                condition = 'true'
                loader = 'epoxy_gl_dlsym({0})'
            else:
                sys.exit('unknown API: "{0}"'.format(api))

            self.process_require_statements(feature, condition, loader, human_name)

        for extension in reg.findall('extensions/extension'):
            extname = extension.get('name')

            self.supported_extensions.add(extname)

            # 'supported' is a set of strings like gl, gles1, gles2,
            # or glx, which are separated by '|'
            apis = extension.get('supported').split('|')
            if 'glx' in apis:
                human_name = 'GLX extension \\"{0}\\"'.format(extname)
                condition = 'epoxy_conservative_has_glx_extension("{0}")'.format(extname)
                loader = 'glXGetProcAddress((const GLubyte *){0})'
                self.process_require_statements(extension, condition, loader, human_name)
            if 'egl' in apis:
                human_name = 'EGL extension \\"{0}\\"'.format(extname)
                condition = 'epoxy_conservative_has_egl_extension("{0}")'.format(extname)
                loader = 'eglGetProcAddress({0})'
                self.process_require_statements(extension, condition, loader, human_name)
            if 'wgl' in apis:
                human_name = 'WGL extension \\"{0}\\"'.format(extname)
                condition = 'epoxy_conservative_has_wgl_extension("{0}")'.format(extname)
                loader = 'wglGetProcAddress({0})'
                self.process_require_statements(extension, condition, loader, human_name)
            if {'gl', 'gles1', 'gles2'}.intersection(apis):
                human_name = 'GL extension \\"{0}\\"'.format(extname)
                condition = 'epoxy_conservative_has_gl_extension("{0}")'.format(extname)
                loader = 'epoxy_get_proc_address({0})'
                self.process_require_statements(extension, condition, loader, human_name)

    def fixup_bootstrap_function(self, name, loader):
        # We handle glGetString(), glGetIntegerv(), and
        # glXGetProcAddressARB() specially, because we need to use
        # them in the process of deciding on loaders for resolving,
        # and the naive code generation would result in their
        # resolvers calling their own resolvers.
        if name not in self.functions:
            return

        func = self.functions[name]
        func.providers = {}
        func.add_provider('true', loader, 'always present')

    def parse(self, file):
        reg = ET.parse(file)
        if reg.find('comment') != None:
            self.copyright_comment = reg.find('comment').text
        else:
            self.copyright_comment = ''
        self.parse_typedefs(reg)
        self.parse_enums(reg)
        self.parse_function_definitions(reg)
        self.parse_function_providers(reg)

    def write_copyright_comment_body(self):
        for line in self.copyright_comment.splitlines():
            if '-----' in line:
                break
            self.outln(' * ' + line)

    def write_enums(self):
        for name in sorted(self.supported_versions):
            self.outln('#define {0} 1'.format(name))
        self.outln('')

        for name in sorted(self.supported_extensions):
            self.outln('#define {0} 1'.format(name))
        self.outln('')

        # We want to sort by enum number (which puts a bunch of things
        # in a logical order), then by name after that, so we do those
        # sorts in reverse.  This is still way uglier than doing some
        # sort based on what version/extensions things are introduced
        # in, but we haven't paid any attention to those attributes
        # for enums yet.
        sorted_by_name = sorted(self.enums.keys())
        sorted_by_number = sorted(sorted_by_name, key=lambda name: self.enums[name])
        for name in sorted_by_number:
            self.outln('#define ' + name.ljust(self.max_enum_name_len + 3) + self.enums[name] + '')

    def write_function_ptr_typedefs(self):
        for func in self.sorted_functions:
            self.outln('typedef {0} (GLAPIENTRY *{1})({2});'.format(func.ret_type,
                                                                    func.ptr_type,
                                                                    func.args_decl))

    def write_header_header(self, file):
        self.out_file = open(file, 'w')

        self.outln('/* GL dispatch header.')
        self.outln(' * This is code-generated from the GL API XML files from Khronos.')
        self.write_copyright_comment_body()
        self.outln(' */')
        self.outln('')

        self.outln('#pragma once')

        self.outln('#include <inttypes.h>')
        self.outln('#include <stddef.h>')
        self.outln('')

    def write_header(self, file):
        self.write_header_header(file)

        if self.target != "gl":
            self.outln('#include "epoxy/gl.h"')
            if self.target == "egl":
                self.outln('#include "EGL/eglplatform.h"')
        else:
            # Add some ridiculous inttypes.h redefinitions that are
            # from khrplatform.h and not included in the XML.  We
            # don't directly include khrplatform.h because it's not
            # present on many systems, and coming up with #ifdefs to
            # decide when it's not present would be hard.
            self.outln('#define __khrplatform_h_ 1')
            self.outln('typedef int8_t khronos_int8_t;')
            self.outln('typedef int16_t khronos_int16_t;')
            self.outln('typedef int32_t khronos_int32_t;')
            self.outln('typedef int64_t khronos_int64_t;')
            self.outln('typedef uint8_t khronos_uint8_t;')
            self.outln('typedef uint16_t khronos_uint16_t;')
            self.outln('typedef uint32_t khronos_uint32_t;')
            self.outln('typedef uint64_t khronos_uint64_t;')
            self.outln('typedef float khronos_float_t;')
            self.outln('typedef long khronos_intptr_t;')
            self.outln('typedef long khronos_ssize_t;')
            self.outln('typedef unsigned long khronos_usize_t;')
            self.outln('typedef uint64_t khronos_utime_nanoseconds_t;')
            self.outln('typedef int64_t khronos_stime_nanoseconds_t;')
            self.outln('#define KHRONOS_MAX_ENUM 0x7FFFFFFF')
            self.outln('typedef enum {')
            self.outln('    KHRONOS_FALSE = 0,')
            self.outln('    KHRONOS_TRUE  = 1,')
            self.outln('    KHRONOS_BOOLEAN_ENUM_FORCE_SIZE = KHRONOS_MAX_ENUM')
            self.outln('} khronos_boolean_enum_t;')
            self.outln('typedef uintptr_t khronos_uintptr_t;')

        if self.target == "glx":
            self.outln('#include <X11/Xlib.h>')
            self.outln('#include <X11/Xutil.h>')

        self.out(self.typedefs)
        self.outln('')
        self.write_enums()
        self.outln('')
        self.write_function_ptr_typedefs()

        for func in self.sorted_functions:
            self.outln('extern EPOXY_IMPORTEXPORT {0} (EPOXY_CALLSPEC *epoxy_{1})({2});'.format(func.ret_type,
                                                                                     func.name,
                                                                                     func.args_decl))
            self.outln('')

        for func in self.sorted_functions:
            self.outln('#define {0} epoxy_{0}'.format(func.name))

    def write_function_ptr_resolver(self, func):
        self.outln('static {0}'.format(func.ptr_type))
        self.outln('epoxy_{0}_resolver(void)'.format(func.wrapped_name))
        self.outln('{')

        providers = []
        # Make a local list of all the providers for this alias group
        alias_root = func;
        if func.alias_func:
            alias_root = func.alias_func
        for provider in alias_root.providers.values():
            providers.append(provider)
        for alias_func in alias_root.alias_exts:
            for provider in alias_func.providers.values():
                providers.append(provider)

        # Add some partial aliases of a few functions.  These are ones
        # that aren't quite aliases, because of some trivial behavior
        # difference (like whether to produce an error for a
        # non-Genned name), but where we'd like to fall back to the
        # similar function if the proper one isn't present.
        half_aliases = {
            'glBindVertexArray' : 'glBindVertexArrayAPPLE',
            'glBindVertexArrayAPPLE' : 'glBindVertexArray',
            'glBindFramebuffer' : 'glBindFramebufferEXT',
            'glBindFramebufferEXT' : 'glBindFramebuffer',
        }
        if func.name in half_aliases:
            alias_func = self.functions[half_aliases[func.name]]
            for provider in alias_func.providers.values():
                providers.append(provider)

        def provider_sort(provider):
            return (provider.name != func.name, provider.name)
        providers.sort(key=provider_sort);

        if len(providers) != 1:
            self.outln('    static const enum {0}_provider providers[] = {{'.format(self.target))
            for provider in providers:
                self.outln('        {0},'.format(provider.enum))
            self.outln('        {0}_provider_terminator'.format(self.target))
            self.outln('    };')

            self.outln('    static const uint16_t entrypoints[] = {')
            for provider in providers:
                self.outln('        {0} /* "{1}" */,'.format(self.entrypoint_string_offset[provider.name], provider.name))
            self.outln('    };')

            self.outln('    return {0}_provider_resolver(entrypoint_strings + {1} /* "{2}" */,'.format(self.target,
                                                                                                       self.entrypoint_string_offset[func.name],
                                                                                                       func.name))
            self.outln('                                providers, entrypoints);')
        else:
            assert(providers[0].name == func.name)
            self.outln('    return {0}_single_resolver({1}, {2} /* {3} */);'.format(self.target,
                                                                                    providers[0].enum,
                                                                                    self.entrypoint_string_offset[func.name],
                                                                                    func.name))
        self.outln('}')
        self.outln('')

    def write_thunks(self, func):
        # Writes out the function that's initially plugged into the
        # global function pointer, which resolves, updates the global
        # function pointer, and calls down to it.
        #
        # It also writes out the actual initialized global function
        # pointer.
        if func.ret_type == 'void':
            self.outln('GEN_THUNKS({0}, ({1}), ({2}))'.format(func.wrapped_name,
                                                              func.args_decl,
                                                              func.args_list))
        else:
            self.outln('GEN_THUNKS_RET({0}, {1}, ({2}), ({3}))'.format(func.ret_type,
                                                                       func.wrapped_name,
                                                                       func.args_decl,
                                                                       func.args_list))

    def write_function_pointer(self, func):
        self.outln('{0}{1} epoxy_{2} = epoxy_{2}_global_rewrite_ptr;'.format(func.public,
                                                                             func.ptr_type,
                                                                             func.wrapped_name))
        self.outln('')

    def write_provider_enums(self):
        # Writes the enum declaration for the list of providers
        # supported by gl_provider_resolver()

        self.outln('enum {0}_provider {{'.format(self.target))

        sorted_providers = sorted(self.provider_enum.keys())

        # We always put a 0 enum first so that we can have a
        # terminator in our arrays
        self.outln('    {0}_provider_terminator = 0,'.format(self.target))

        for human_name in sorted_providers:
            enum = self.provider_enum[human_name]
            self.outln('    {0},'.format(enum))
        self.outln('};')
        self.outln('')

    def write_provider_enum_strings(self):
        # Writes the mapping from enums to the strings describing them
        # for epoxy_print_failure_reasons().

        self.outln('static const char *enum_strings[] = {')

        sorted_providers = sorted(self.provider_enum.keys())

        for human_name in sorted_providers:
            enum = self.provider_enum[human_name]
            self.outln('    [{0}] = "{1}",'.format(enum, human_name))
        self.outln('};')
        self.outln('')

    def write_entrypoint_strings(self):
        self.entrypoint_string_offset = {}

        self.outln('static const char entrypoint_strings[] = ')
        offset = 0
        for func in self.sorted_functions:
            if func.name not in self.entrypoint_string_offset:
                self.entrypoint_string_offset[func.name] = offset
                offset += len(func.name) + 1
                self.outln('   "{0}\\0"'.format(func.name))
        self.outln('    ;')
        # We're using uint16_t for the offsets.
        assert(offset < 65536)
        self.outln('')

    def write_provider_resolver(self):
        self.outln('static void *{0}_provider_resolver(const char *name,'.format(self.target))
        self.outln('                                   const enum {0}_provider *providers,'.format(self.target))
        self.outln('                                   const uint16_t *entrypoints)')
        self.outln('{')
        self.outln('    int i;')

        self.outln('    for (i = 0; providers[i] != {0}_provider_terminator; i++) {{'.format(self.target))
        self.outln('        switch (providers[i]) {')

        for human_name in sorted(self.provider_enum.keys()):
            enum = self.provider_enum[human_name]
            self.outln('        case {0}:'.format(enum))
            self.outln('            if ({0})'.format(self.provider_condition[human_name]))
            self.outln('                return {0};'.format(self.provider_loader[human_name]).format("entrypoint_strings + entrypoints[i]"))
            self.outln('            break;')

        self.outln('        case {0}_provider_terminator:'.format(self.target))
        self.outln('            abort(); /* Not reached */')
        self.outln('        }')
        self.outln('    }')
        self.outln('')

        # If the function isn't provided by any known extension, print
        # something useful for the poor application developer before
        # aborting.  (In non-epoxy GL usage, the app developer would
        # call into some blank stub function and segfault).
        self.outln('    epoxy_print_failure_reasons(name, enum_strings, (const int *)providers);')
        self.outln('    abort();')

        self.outln('}')
        self.outln('')

        single_resolver_proto = '{0}_single_resolver(enum {0}_provider provider, uint16_t entrypoint_offset)'.format(self.target)
        self.outln('static void *')
        self.outln('{0} __attribute__((noinline));'.format(single_resolver_proto))
        self.outln('')
        self.outln('static void *')
        self.outln('{0}'.format(single_resolver_proto))
        self.outln('{')
        self.outln('    enum {0}_provider providers[] = {{'.format(self.target))
        self.outln('        provider,')
        self.outln('        {0}_provider_terminator'.format(self.target))
        self.outln('    };')
        self.outln('    return {0}_provider_resolver(entrypoint_strings + entrypoint_offset,'.format(self.target))
        self.outln('                                providers, &entrypoint_offset);')
        self.outln('}')
        self.outln('')

    def write_source(self, file):
        self.out_file = open(file, 'w')

        self.outln('/* GL dispatch code.')
        self.outln(' * This is code-generated from the GL API XML files from Khronos.')
        self.write_copyright_comment_body()
        self.outln(' */')
        self.outln('')
        self.outln('#include <stdlib.h>')
        self.outln('#include <string.h>')
        self.outln('#include <stdio.h>')
        self.outln('')
        self.outln('#include "dispatch_common.h"')
        self.outln('#include "epoxy/{0}.h"'.format(self.target))
        self.outln('')

        self.outln('struct dispatch_table {')
        for func in self.sorted_functions:
            self.outln('    {0} epoxy_{1};'.format(func.ptr_type, func.wrapped_name))
        self.outln('};')
        self.outln('')

        # Early declaration, so we can declare the real thing at the
        # bottom. (I want the function_ptr_resolver as the first
        # per-GL-call code, since it's the most interesting to see
        # when you search for the implementation of a call)
        self.outln('#if USING_DISPATCH_TABLE')
        self.outln('static inline struct dispatch_table *')
        self.outln('get_dispatch_table(void);')
        self.outln('')
        self.outln('#endif')

        self.write_provider_enums()
        self.write_provider_enum_strings()
        self.write_entrypoint_strings()
        self.write_provider_resolver()

        for func in self.sorted_functions:
            self.write_function_ptr_resolver(func)

        for func in self.sorted_functions:
            self.write_thunks(func)

        self.outln('#if USING_DISPATCH_TABLE')

        self.outln('static struct dispatch_table resolver_table = {')
        for func in self.sorted_functions:
            self.outln('    .{0} = epoxy_{0}_dispatch_table_rewrite_ptr,'.format(func.wrapped_name))
        self.outln('};')
        self.outln('')

        self.outln('uint32_t {0}_tls_index;'.format(self.target))
        self.outln('uint32_t {0}_tls_size = sizeof(struct dispatch_table);'.format(self.target))
        self.outln('')

        self.outln('static inline struct dispatch_table *')
        self.outln('get_dispatch_table(void)')
        self.outln('{')
        self.outln('	return TlsGetValue({0}_tls_index);'.format(self.target))
        self.outln('}')
        self.outln('')

        self.outln('void')
        self.outln('{0}_init_dispatch_table(void)'.format(self.target))
        self.outln('{')
        self.outln('    struct dispatch_table *dispatch_table = get_dispatch_table();')
        self.outln('    memcpy(dispatch_table, &resolver_table, sizeof(resolver_table));')
        self.outln('}')
        self.outln('')

        self.outln('void')
        self.outln('{0}_switch_to_dispatch_table(void)'.format(self.target))
        self.outln('{')

        for func in self.sorted_functions:
            self.outln('    epoxy_{0} = epoxy_{0}_dispatch_table_thunk;'.format(func.wrapped_name))

        self.outln('}')
        self.outln('')

        self.outln('#endif /* !USING_DISPATCH_TABLE */')

        for func in self.sorted_functions:
            self.write_function_pointer(func)

argparser = argparse.ArgumentParser(description='Generate GL dispatch wrappers.')
argparser.add_argument('files', metavar='file.xml', nargs='+', help='GL API XML files to be parsed')
argparser.add_argument('--dir', metavar='dir', required=True, help='Destination directory')
args = argparser.parse_args()

srcdir = args.dir + '/src/'
incdir = args.dir + '/include/epoxy/'

for file in args.files:
    name = os.path.basename(file).split('.xml')[0]
    generator = Generator(name)
    generator.parse(file)

    generator.drop_weird_glx_functions()

    # This is an ANSI vs Unicode function, handled specially by
    # include/epoxy/wgl.h
    if 'wglUseFontBitmaps' in generator.functions:
        del generator.functions['wglUseFontBitmaps']

    generator.sort_functions()
    generator.resolve_aliases()
    generator.fixup_bootstrap_function('glGetString',
                                       'epoxy_get_bootstrap_proc_address({0})')
    generator.fixup_bootstrap_function('glGetIntegerv',
                                       'epoxy_get_bootstrap_proc_address({0})')

    # While this is technically exposed as a GLX extension, it's
    # required to be present as a public symbol by the Linux OpenGL
    # ABI.
    generator.fixup_bootstrap_function('glXGetProcAddress',
                                       'epoxy_glx_dlsym({0})')

    generator.prepare_provider_enum()

    generator.write_header(incdir + name + '_generated.h')
    generator.write_source(srcdir + name + '_generated_dispatch.c')