Source

pypy / ctypes_configure / configure.py

  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
#! /usr/bin/env python

import os, py, sys
import ctypes
from ctypes_configure.cbuild import build_executable, configdir, try_compile
from ctypes_configure.cbuild import ExternalCompilationInfo
import distutils

# ____________________________________________________________
#
# Helpers for simple cases

def eci_from_header(c_header_source):
    return ExternalCompilationInfo(
        pre_include_lines=c_header_source.split("\n")
    )


def getstruct(name, c_header_source, interesting_fields):
    class CConfig:
        _compilation_info_ = eci_from_header(c_header_source)
        STRUCT = Struct(name, interesting_fields)
    return configure(CConfig)['STRUCT']

def getsimpletype(name, c_header_source, ctype_hint=ctypes.c_int):
    class CConfig:
        _compilation_info_ = eci_from_header(c_header_source)
        TYPE = SimpleType(name, ctype_hint)
    return configure(CConfig)['TYPE']

def getconstantinteger(name, c_header_source):
    class CConfig:
        _compilation_info_ = eci_from_header(c_header_source)
        CONST = ConstantInteger(name)
    return configure(CConfig)['CONST']

def getdefined(macro, c_header_source):
    class CConfig:
        _compilation_info_ = eci_from_header(c_header_source)
        DEFINED = Defined(macro)
    return configure(CConfig)['DEFINED']

def has(name, c_header_source):
    class CConfig:
        _compilation_info_ = eci_from_header(c_header_source)
        HAS = Has(name)
    return configure(CConfig)['HAS']

def check_eci(eci):
    """Check if a given ExternalCompilationInfo compiles and links."""
    class CConfig:
        _compilation_info_ = eci
        WORKS = Works()
    return configure(CConfig)['WORKS']

def sizeof(name, eci, **kwds):
    class CConfig:
        _compilation_info_ = eci
        SIZE = SizeOf(name)
    for k, v in kwds.items():
        setattr(CConfig, k, v)
    return configure(CConfig)['SIZE']

def memory_alignment():
    """Return the alignment (in bytes) of memory allocations.
    This is enough to make sure a structure with pointers and 'double'
    fields is properly aligned."""
    global _memory_alignment
    if _memory_alignment is None:
        S = getstruct('struct memory_alignment_test', """
           struct memory_alignment_test {
               double d;
               void* p;
           };
        """, [])
        result = ctypes.alignment(S)
        assert result & (result-1) == 0, "not a power of two??"
        _memory_alignment = result
    return _memory_alignment
_memory_alignment = None

# ____________________________________________________________
#
# General interface

class ConfigResult:
    def __init__(self, CConfig, info, entries):
        self.CConfig = CConfig
        self.result = {}
        self.info = info
        self.entries = entries
        
    def get_entry_result(self, entry):
        try:
            return self.result[entry]
        except KeyError:
            pass
        name = self.entries[entry]
        info = self.info[name]
        self.result[entry] = entry.build_result(info, self)

    def get_result(self):
        return dict([(name, self.result[entry])
                     for entry, name in self.entries.iteritems()])


class _CWriter(object):
    """ A simple class which aggregates config parts
    """
    def __init__(self, CConfig):
        self.path = uniquefilepath()
        self.f = self.path.open("w")
        self.config = CConfig

    def write_header(self):
        f = self.f
        CConfig = self.config
        CConfig._compilation_info_.write_c_header(f)
        print >> f, C_HEADER
        print >> f

    def write_entry(self, key, entry):
        f = self.f
        print >> f, 'void dump_section_%s(void) {' % (key,)
        for line in entry.prepare_code():
            if line and line[0] != '#':
                line = '\t' + line
            print >> f, line
        print >> f, '}'
        print >> f

    def write_entry_main(self, key):
        print >> self.f, '\tprintf("-+- %s\\n");' % (key,)
        print >> self.f, '\tdump_section_%s();' % (key,)
        print >> self.f, '\tprintf("---\\n");'

    def start_main(self):
        print >> self.f, 'int main(int argc, char *argv[]) {'

    def close(self):
        f = self.f
        print >> f, '\treturn 0;'
        print >> f, '}'
        f.close()

    def ask_gcc(self, question):
        self.start_main()
        self.f.write(question + "\n")
        self.close()
        eci = self.config._compilation_info_
        return try_compile([self.path], eci)

        
def configure(CConfig, noerr=False):
    """Examine the local system by running the C compiler.
    The CConfig class contains CConfigEntry attribues that describe
    what should be inspected; configure() returns a dict mapping
    names to the results.
    """
    for attr in ['_includes_', '_libraries_', '_sources_', '_library_dirs_',
                 '_include_dirs_', '_header_']:
        assert not hasattr(CConfig, attr), "Found legacy attribut %s on CConfig" % (attr,)
    entries = []
    for key in dir(CConfig):
        value = getattr(CConfig, key)
        if isinstance(value, CConfigEntry):
            entries.append((key, value))

    if entries:   # can be empty if there are only CConfigSingleEntries
        writer = _CWriter(CConfig)
        writer.write_header()
        for key, entry in entries:
            writer.write_entry(key, entry)

        f = writer.f
        writer.start_main()
        for key, entry in entries:
            writer.write_entry_main(key)
        writer.close()

        eci = CConfig._compilation_info_
        infolist = list(run_example_code(writer.path, eci, noerr=noerr))
        assert len(infolist) == len(entries)

        resultinfo = {}
        resultentries = {}
        for info, (key, entry) in zip(infolist, entries):
            resultinfo[key] = info
            resultentries[entry] = key

        result = ConfigResult(CConfig, resultinfo, resultentries)
        for name, entry in entries:
            result.get_entry_result(entry)
        res = result.get_result()
    else:
        res = {}

    for key in dir(CConfig):
        value = getattr(CConfig, key)
        if isinstance(value, CConfigSingleEntry):
            writer = _CWriter(CConfig)
            writer.write_header()
            res[key] = value.question(writer.ask_gcc)
    return res

# ____________________________________________________________


class CConfigEntry(object):
    "Abstract base class."

class Struct(CConfigEntry):
    """An entry in a CConfig class that stands for an externally
    defined structure.
    """
    def __init__(self, name, interesting_fields, ifdef=None):
        self.name = name
        self.interesting_fields = interesting_fields
        self.ifdef = ifdef

    def prepare_code(self):
        if self.ifdef is not None:
            yield '#ifdef %s' % (self.ifdef,)
        yield 'typedef %s ctypesplatcheck_t;' % (self.name,)
        yield 'typedef struct {'
        yield '    char c;'
        yield '    ctypesplatcheck_t s;'
        yield '} ctypesplatcheck2_t;'
        yield ''
        yield 'ctypesplatcheck_t s;'
        if self.ifdef is not None:
            yield 'dump("defined", 1);'
        yield 'dump("align", offsetof(ctypesplatcheck2_t, s));'
        yield 'dump("size",  sizeof(ctypesplatcheck_t));'
        for fieldname, fieldtype in self.interesting_fields:
            yield 'dump("fldofs %s", offsetof(ctypesplatcheck_t, %s));'%(
                fieldname, fieldname)
            yield 'dump("fldsize %s",   sizeof(s.%s));' % (
                fieldname, fieldname)
            if fieldtype in integer_class:
                yield 's.%s = 0; s.%s = ~s.%s;' % (fieldname,
                                                   fieldname,
                                                   fieldname)
                yield 'dump("fldunsigned %s", s.%s > 0);' % (fieldname,
                                                             fieldname)
        if self.ifdef is not None:
            yield '#else'
            yield 'dump("defined", 0);'
            yield '#endif'

    def build_result(self, info, config_result):
        if self.ifdef is not None:
            if not info['defined']:
                return None
        alignment = 1
        layout = [None] * info['size']
        for fieldname, fieldtype in self.interesting_fields:
            if isinstance(fieldtype, Struct):
                offset = info['fldofs '  + fieldname]
                size   = info['fldsize ' + fieldname]
                c_fieldtype = config_result.get_entry_result(fieldtype)
                layout_addfield(layout, offset, c_fieldtype, fieldname)
                alignment = max(alignment, ctype_alignment(c_fieldtype))
            else:
                offset = info['fldofs '  + fieldname]
                size   = info['fldsize ' + fieldname]
                sign   = info.get('fldunsigned ' + fieldname, False)
                if (size, sign) != size_and_sign(fieldtype):
                    fieldtype = fixup_ctype(fieldtype, fieldname, (size, sign))
                layout_addfield(layout, offset, fieldtype, fieldname)
                alignment = max(alignment, ctype_alignment(fieldtype))

        # try to enforce the same alignment as the one of the original
        # structure
        if alignment < info['align']:
            choices = [ctype for ctype in alignment_types
                             if ctype_alignment(ctype) == info['align']]
            assert choices, "unsupported alignment %d" % (info['align'],)
            choices = [(ctypes.sizeof(ctype), i, ctype)
                       for i, ctype in enumerate(choices)]
            csize, _, ctype = min(choices)
            for i in range(0, info['size'] - csize + 1, info['align']):
                if layout[i:i+csize] == [None] * csize:
                    layout_addfield(layout, i, ctype, '_alignment')
                    break
            else:
                raise AssertionError("unenforceable alignment %d" % (
                    info['align'],))

        n = 0
        for i, cell in enumerate(layout):
            if cell is not None:
                continue
            layout_addfield(layout, i, ctypes.c_char, '_pad%d' % (n,))
            n += 1

        # build the ctypes Structure
        seen = {}
        fields = []
        for cell in layout:
            if cell in seen:
                continue
            fields.append((cell.name, cell.ctype))
            seen[cell] = True

        class S(ctypes.Structure):
            _fields_ = fields
        name = self.name
        if name.startswith('struct '):
            name = name[7:]
        S.__name__ = name
        return S

class SimpleType(CConfigEntry):
    """An entry in a CConfig class that stands for an externally
    defined simple numeric type.
    """
    def __init__(self, name, ctype_hint=ctypes.c_int, ifdef=None):
        self.name = name
        self.ctype_hint = ctype_hint
        self.ifdef = ifdef
        
    def prepare_code(self):
        if self.ifdef is not None:
            yield '#ifdef %s' % (self.ifdef,)
        yield 'typedef %s ctypesplatcheck_t;' % (self.name,)
        yield ''
        yield 'ctypesplatcheck_t x;'
        if self.ifdef is not None:
            yield 'dump("defined", 1);'
        yield 'dump("size",  sizeof(ctypesplatcheck_t));'
        if self.ctype_hint in integer_class:
            yield 'x = 0; x = ~x;'
            yield 'dump("unsigned", x > 0);'
        if self.ifdef is not None:
            yield '#else'
            yield 'dump("defined", 0);'
            yield '#endif'

    def build_result(self, info, config_result):
        if self.ifdef is not None and not info['defined']:
            return None
        size = info['size']
        sign = info.get('unsigned', False)
        ctype = self.ctype_hint
        if (size, sign) != size_and_sign(ctype):
            ctype = fixup_ctype(ctype, self.name, (size, sign))
        return ctype

class ConstantInteger(CConfigEntry):
    """An entry in a CConfig class that stands for an externally
    defined integer constant.
    """
    def __init__(self, name):
        self.name = name

    def prepare_code(self):
        yield 'if ((%s) < 0) {' % (self.name,)
        yield '    long long x = (long long)(%s);' % (self.name,)
        yield '    printf("value: %lld\\n", x);'
        yield '} else {'
        yield '    unsigned long long x = (unsigned long long)(%s);' % (
                        self.name,)
        yield '    printf("value: %llu\\n", x);'
        yield '}'

    def build_result(self, info, config_result):
        return info['value']

class DefinedConstantInteger(CConfigEntry):
    """An entry in a CConfig class that stands for an externally
    defined integer constant. If not #defined the value will be None.
    """
    def __init__(self, macro):
        self.name = self.macro = macro

    def prepare_code(self):
        yield '#ifdef %s' % self.macro
        yield 'dump("defined", 1);'
        yield 'if ((%s) < 0) {' % (self.macro,)
        yield '    long long x = (long long)(%s);' % (self.macro,)
        yield '    printf("value: %lld\\n", x);'
        yield '} else {'
        yield '    unsigned long long x = (unsigned long long)(%s);' % (
                        self.macro,)
        yield '    printf("value: %llu\\n", x);'
        yield '}'
        yield '#else'
        yield 'dump("defined", 0);'
        yield '#endif'

    def build_result(self, info, config_result):
        if info["defined"]:
            return info['value']
        return None


class DefinedConstantString(CConfigEntry):
    """
    """
    def __init__(self, macro):
        self.macro = macro
        self.name = macro

    def prepare_code(self):
        yield '#ifdef %s' % self.macro
        yield 'int i;'
        yield 'char *p = %s;' % self.macro
        yield 'dump("defined", 1);'
        yield 'for (i = 0; p[i] != 0; i++ ) {'
        yield '  printf("value_%d: %d\\n", i, (int)(unsigned char)p[i]);'
        yield '}'
        yield '#else'
        yield 'dump("defined", 0);'
        yield '#endif'

    def build_result(self, info, config_result):
        if info["defined"]:
            string = ''
            d = 0
            while info.has_key('value_%d' % d):
                string += chr(info['value_%d' % d])
                d += 1
            return string
        return None


class Defined(CConfigEntry):
    """A boolean, corresponding to an #ifdef.
    """
    def __init__(self, macro):
        self.macro = macro
        self.name = macro

    def prepare_code(self):
        yield '#ifdef %s' % (self.macro,)
        yield 'dump("defined", 1);'
        yield '#else'
        yield 'dump("defined", 0);'
        yield '#endif'

    def build_result(self, info, config_result):
        return bool(info['defined'])

class CConfigSingleEntry(object):
    """ An abstract class of type which requires
    gcc succeeding/failing instead of only asking
    """
    pass

class Has(CConfigSingleEntry):
    def __init__(self, name):
        self.name = name
    
    def question(self, ask_gcc):
        return ask_gcc(self.name + ';')

class Works(CConfigSingleEntry):
    def question(self, ask_gcc):
        return ask_gcc("")

class SizeOf(CConfigEntry):
    """An entry in a CConfig class that stands for
    some external opaque type
    """
    def __init__(self, name):
        self.name = name

    def prepare_code(self):
        yield 'dump("size",  sizeof(%s));' % self.name

    def build_result(self, info, config_result):
        return info['size']

# ____________________________________________________________
#
# internal helpers

def ctype_alignment(c_type):
    if issubclass(c_type, ctypes.Structure):
        return max([ctype_alignment(fld_type)
                     for fld_name, fld_type in c_type._fields_])
    
    return ctypes.alignment(c_type)

def uniquefilepath(LAST=[0]):
    i = LAST[0]
    LAST[0] += 1
    return configdir.join('ctypesplatcheck_%d.c' % i)

alignment_types = [
    ctypes.c_short,
    ctypes.c_int,
    ctypes.c_long,
    ctypes.c_float,
    ctypes.c_double,
    ctypes.c_char_p,
    ctypes.c_void_p,
    ctypes.c_longlong,
    ctypes.c_wchar,
    ctypes.c_wchar_p,
    ]

integer_class = [ctypes.c_byte,     ctypes.c_ubyte,
                 ctypes.c_short,    ctypes.c_ushort,
                 ctypes.c_int,      ctypes.c_uint,
                 ctypes.c_long,     ctypes.c_ulong,
                 ctypes.c_longlong, ctypes.c_ulonglong,
                 ]
float_class = [ctypes.c_float, ctypes.c_double]

class Field(object):
    def __init__(self, name, ctype):
        self.name = name
        self.ctype = ctype
    def __repr__(self):
        return '<field %s: %s>' % (self.name, self.ctype)

def layout_addfield(layout, offset, ctype, prefix):
    size = ctypes.sizeof(ctype)
    name = prefix
    i = 0
    while name in layout:
        i += 1
        name = '%s_%d' % (prefix, i)
    field = Field(name, ctype)
    for i in range(offset, offset+size):
        assert layout[i] is None, "%s overlaps %r" % (fieldname, layout[i])
        layout[i] = field
    return field

def size_and_sign(ctype):
    return (ctypes.sizeof(ctype),
            ctype in integer_class and ctype(-1).value > 0)

def fixup_ctype(fieldtype, fieldname, expected_size_and_sign):
    for typeclass in [integer_class, float_class]:
        if fieldtype in typeclass:
            for ctype in typeclass:
                if size_and_sign(ctype) == expected_size_and_sign:
                    return ctype
    if (hasattr(fieldtype, '_length_')
        and getattr(fieldtype, '_type_', None) == ctypes.c_char):
        # for now, assume it is an array of chars; otherwise we'd also
        # have to check the exact integer type of the elements of the array
        size, sign = expected_size_and_sign
        return ctypes.c_char * size
    if (hasattr(fieldtype, '_length_')
        and getattr(fieldtype, '_type_', None) == ctypes.c_ubyte):
        # grumble, fields of type 'c_char array' have automatic cast-to-
        # Python-string behavior in ctypes, which may not be what you
        # want, so here is the same with c_ubytes instead...
        size, sign = expected_size_and_sign
        return ctypes.c_ubyte * size
    raise TypeError("conflicting field type %r for %r" % (fieldtype,
                                                          fieldname))


C_HEADER = """
#include <stdio.h>
#include <stddef.h>   /* for offsetof() */
#ifndef _WIN32
#  include <stdint.h>   /* FreeBSD: for uint64_t */
#endif

void dump(char* key, int value) {
    printf("%s: %d\\n", key, value);
}
"""

def run_example_code(filepath, eci, noerr=False):
    executable = build_executable([filepath], eci, noerr=noerr)
    output = py.process.cmdexec(executable)
    section = None
    for line in output.splitlines():
        line = line.strip()
        if line.startswith('-+- '):      # start of a new section
            section = {}
        elif line == '---':              # section end
            assert section is not None
            yield section
            section = None
        elif line:
            assert section is not None
            key, value = line.split(': ')
            section[key] = int(value)

# ____________________________________________________________

def get_python_include_dir():
    from distutils import sysconfig
    gcv = sysconfig.get_config_vars()
    return gcv['INCLUDEPY']

if __name__ == '__main__':
    doc = """Example:
    
       ctypes_platform.py  -h sys/types.h  -h netinet/in.h
                           'struct sockaddr_in'
                           sin_port  c_int
    """
    import sys, getopt
    opts, args = getopt.gnu_getopt(sys.argv[1:], 'h:')
    if not args:
        print >> sys.stderr, doc
    else:
        assert len(args) % 2 == 1
        headers = []
        for opt, value in opts:
            if opt == '-h':
                headers.append('#include <%s>' % (value,))
        name = args[0]
        fields = []
        for i in range(1, len(args), 2):
            ctype = getattr(ctypes, args[i+1])
            fields.append((args[i], ctype))

        S = getstruct(name, '\n'.join(headers), fields)

        for key, value in S._fields_:
            print key, value
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.