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
Lib/distutils/msvc9compiler.py
"""distutils.msvc9compiler

Contains MSVCCompiler, an implementation of the abstract CCompiler class
for the Microsoft Visual Studio 2008.

The module is compatible with VS 2005 and VS 2008. You can find legacy support
for older versions of VS in distutils.msvccompiler.
"""

# Written by Perry Stoll
# hacked by Robin Becker and Thomas Heller to do a better job of
#   finding DevStudio (through the registry)
# ported to VS2005 and VS 2008 by Christian Heimes

__revision__ = "$Id$"

import os
import subprocess
import sys
import re

from distutils.errors import (DistutilsExecError, DistutilsPlatformError,
                              CompileError, LibError, LinkError)
from distutils.ccompiler import CCompiler, gen_lib_options
from distutils import log
from distutils.util import get_platform

import _winreg

RegOpenKeyEx = _winreg.OpenKeyEx
RegEnumKey = _winreg.EnumKey
RegEnumValue = _winreg.EnumValue
RegError = _winreg.error

HKEYS = (_winreg.HKEY_USERS,
         _winreg.HKEY_CURRENT_USER,
         _winreg.HKEY_LOCAL_MACHINE,
         _winreg.HKEY_CLASSES_ROOT)

NATIVE_WIN64 = (sys.platform == 'win32' and sys.maxsize > 2**32)
if NATIVE_WIN64:
    # Visual C++ is a 32-bit application, so we need to look in
    # the corresponding registry branch, if we're running a
    # 64-bit Python on Win64
    VS_BASE = r"Software\Wow6432Node\Microsoft\VisualStudio\%0.1f"
    VSEXPRESS_BASE = r"Software\Wow6432Node\Microsoft\VCExpress\%0.1f"
    WINSDK_BASE = r"Software\Wow6432Node\Microsoft\Microsoft SDKs\Windows"
    NET_BASE = r"Software\Wow6432Node\Microsoft\.NETFramework"
else:
    VS_BASE = r"Software\Microsoft\VisualStudio\%0.1f"
    VSEXPRESS_BASE = r"Software\Microsoft\VCExpress\%0.1f"
    WINSDK_BASE = r"Software\Microsoft\Microsoft SDKs\Windows"
    NET_BASE = r"Software\Microsoft\.NETFramework"

# A map keyed by get_platform() return values to values accepted by
# 'vcvarsall.bat'.  Note a cross-compile may combine these (eg, 'x86_amd64' is
# the param to cross-compile on x86 targetting amd64.)
PLAT_TO_VCVARS = {
    'win32' : 'x86',
    'win-amd64' : 'amd64',
    'win-ia64' : 'ia64',
}

class Reg:
    """Helper class to read values from the registry
    """

    def get_value(cls, path, key):
        for base in HKEYS:
            d = cls.read_values(base, path)
            if d and key in d:
                return d[key]
        raise KeyError(key)
    get_value = classmethod(get_value)

    def read_keys(cls, base, key):
        """Return list of registry keys."""
        try:
            handle = RegOpenKeyEx(base, key)
        except RegError:
            return None
        L = []
        i = 0
        while True:
            try:
                k = RegEnumKey(handle, i)
            except RegError:
                break
            L.append(k)
            i += 1
        return L
    read_keys = classmethod(read_keys)

    def read_values(cls, base, key):
        """Return dict of registry keys and values.

        All names are converted to lowercase.
        """
        try:
            handle = RegOpenKeyEx(base, key)
        except RegError:
            return None
        d = {}
        i = 0
        while True:
            try:
                name, value, type = RegEnumValue(handle, i)
            except RegError:
                break
            name = name.lower()
            d[cls.convert_mbcs(name)] = cls.convert_mbcs(value)
            i += 1
        return d
    read_values = classmethod(read_values)

    def convert_mbcs(s):
        dec = getattr(s, "decode", None)
        if dec is not None:
            try:
                s = dec("mbcs")
            except UnicodeError:
                pass
        return s
    convert_mbcs = staticmethod(convert_mbcs)

class MacroExpander:

    def __init__(self, version):
        self.macros = {}
        self.vsbase = VS_BASE % version
        self.load_macros(version)

    def set_macro(self, macro, path, key):
        self.macros["$(%s)" % macro] = Reg.get_value(path, key)

    def load_macros(self, version):
        self.set_macro("VCInstallDir", self.vsbase + r"\Setup\VC", "productdir")
        self.set_macro("VSInstallDir", self.vsbase + r"\Setup\VS", "productdir")
        self.set_macro("FrameworkDir", NET_BASE, "installroot")
        try:
            if version >= 8.0:
                self.set_macro("FrameworkSDKDir", NET_BASE,
                               "sdkinstallrootv2.0")
            else:
                raise KeyError("sdkinstallrootv2.0")
        except KeyError:
            raise DistutilsPlatformError(
            """Python was built with Visual Studio 2008;
extensions must be built with a compiler than can generate compatible binaries.
Visual Studio 2008 was not found on this system. If you have Cygwin installed,
you can try compiling with MingW32, by passing "-c mingw32" to setup.py.""")

        if version >= 9.0:
            self.set_macro("FrameworkVersion", self.vsbase, "clr version")
            self.set_macro("WindowsSdkDir", WINSDK_BASE, "currentinstallfolder")
        else:
            p = r"Software\Microsoft\NET Framework Setup\Product"
            for base in HKEYS:
                try:
                    h = RegOpenKeyEx(base, p)
                except RegError:
                    continue
                key = RegEnumKey(h, 0)
                d = Reg.get_value(base, r"%s\%s" % (p, key))
                self.macros["$(FrameworkVersion)"] = d["version"]

    def sub(self, s):
        for k, v in self.macros.items():
            s = s.replace(k, v)
        return s

def get_build_version():
    """Return the version of MSVC that was used to build Python.

    For Python 2.3 and up, the version number is included in
    sys.version.  For earlier versions, assume the compiler is MSVC 6.
    """
    prefix = "MSC v."
    i = sys.version.find(prefix)
    if i == -1:
        return 6
    i = i + len(prefix)
    s, rest = sys.version[i:].split(" ", 1)
    majorVersion = int(s[:-2]) - 6
    minorVersion = int(s[2:3]) / 10.0
    # I don't think paths are affected by minor version in version 6
    if majorVersion == 6:
        minorVersion = 0
    if majorVersion >= 6:
        return majorVersion + minorVersion
    # else we don't know what version of the compiler this is
    return None

def normalize_and_reduce_paths(paths):
    """Return a list of normalized paths with duplicates removed.

    The current order of paths is maintained.
    """
    # Paths are normalized so things like:  /a and /a/ aren't both preserved.
    reduced_paths = []
    for p in paths:
        np = os.path.normpath(p)
        # XXX(nnorwitz): O(n**2), if reduced_paths gets long perhaps use a set.
        if np not in reduced_paths:
            reduced_paths.append(np)
    return reduced_paths

def removeDuplicates(variable):
    """Remove duplicate values of an environment variable.
    """
    oldList = variable.split(os.pathsep)
    newList = []
    for i in oldList:
        if i not in newList:
            newList.append(i)
    newVariable = os.pathsep.join(newList)
    return newVariable

def find_vcvarsall(version):
    """Find the vcvarsall.bat file

    At first it tries to find the productdir of VS 2008 in the registry. If
    that fails it falls back to the VS90COMNTOOLS env var.
    """
    vsbase = VS_BASE % version
    try:
        productdir = Reg.get_value(r"%s\Setup\VC" % vsbase,
                                   "productdir")
    except KeyError:
        productdir = None

    # trying Express edition
    if productdir is None:
        vsbase = VSEXPRESS_BASE % version
        try:
            productdir = Reg.get_value(r"%s\Setup\VC" % vsbase,
                                       "productdir")
        except KeyError:
            productdir = None
            log.debug("Unable to find productdir in registry")

    if not productdir or not os.path.isdir(productdir):
        toolskey = "VS%0.f0COMNTOOLS" % version
        toolsdir = os.environ.get(toolskey, None)

        if toolsdir and os.path.isdir(toolsdir):
            productdir = os.path.join(toolsdir, os.pardir, os.pardir, "VC")
            productdir = os.path.abspath(productdir)
            if not os.path.isdir(productdir):
                log.debug("%s is not a valid directory" % productdir)
                return None
        else:
            log.debug("Env var %s is not set or invalid" % toolskey)
    if not productdir:
        log.debug("No productdir found")
        return None
    vcvarsall = os.path.join(productdir, "vcvarsall.bat")
    if os.path.isfile(vcvarsall):
        return vcvarsall
    log.debug("Unable to find vcvarsall.bat")
    return None

def query_vcvarsall(version, arch="x86"):
    """Launch vcvarsall.bat and read the settings from its environment
    """
    vcvarsall = find_vcvarsall(version)
    interesting = set(("include", "lib", "libpath", "path"))
    result = {}

    if vcvarsall is None:
        raise DistutilsPlatformError("Unable to find vcvarsall.bat")
    log.debug("Calling 'vcvarsall.bat %s' (version=%s)", arch, version)
    popen = subprocess.Popen('"%s" %s & set' % (vcvarsall, arch),
                             stdout=subprocess.PIPE,
                             stderr=subprocess.PIPE)
    try:
        stdout, stderr = popen.communicate()
        if popen.wait() != 0:
            raise DistutilsPlatformError(stderr.decode("mbcs"))

        stdout = stdout.decode("mbcs")
        for line in stdout.split("\n"):
            line = Reg.convert_mbcs(line)
            if '=' not in line:
                continue
            line = line.strip()
            key, value = line.split('=', 1)
            key = key.lower()
            if key in interesting:
                if value.endswith(os.pathsep):
                    value = value[:-1]
                result[key] = removeDuplicates(value)

    finally:
        popen.stdout.close()
        popen.stderr.close()

    if len(result) != len(interesting):
        raise ValueError(str(list(result.keys())))

    return result

# More globals
VERSION = get_build_version()
if VERSION < 8.0:
    raise DistutilsPlatformError("VC %0.1f is not supported by this module" % VERSION)
# MACROS = MacroExpander(VERSION)

class MSVCCompiler(CCompiler) :
    """Concrete class that implements an interface to Microsoft Visual C++,
       as defined by the CCompiler abstract class."""

    compiler_type = 'msvc'

    # Just set this so CCompiler's constructor doesn't barf.  We currently
    # don't use the 'set_executables()' bureaucracy provided by CCompiler,
    # as it really isn't necessary for this sort of single-compiler class.
    # Would be nice to have a consistent interface with UnixCCompiler,
    # though, so it's worth thinking about.
    executables = {}

    # Private class data (need to distinguish C from C++ source for compiler)
    _c_extensions = ['.c']
    _cpp_extensions = ['.cc', '.cpp', '.cxx']
    _rc_extensions = ['.rc']
    _mc_extensions = ['.mc']

    # Needed for the filename generation methods provided by the
    # base class, CCompiler.
    src_extensions = (_c_extensions + _cpp_extensions +
                      _rc_extensions + _mc_extensions)
    res_extension = '.res'
    obj_extension = '.obj'
    static_lib_extension = '.lib'
    shared_lib_extension = '.dll'
    static_lib_format = shared_lib_format = '%s%s'
    exe_extension = '.exe'

    def __init__(self, verbose=0, dry_run=0, force=0):
        CCompiler.__init__ (self, verbose, dry_run, force)
        self.__version = VERSION
        self.__root = r"Software\Microsoft\VisualStudio"
        # self.__macros = MACROS
        self.__paths = []
        # target platform (.plat_name is consistent with 'bdist')
        self.plat_name = None
        self.__arch = None # deprecated name
        self.initialized = False

    def initialize(self, plat_name=None):
        # multi-init means we would need to check platform same each time...
        assert not self.initialized, "don't init multiple times"
        if plat_name is None:
            plat_name = get_platform()
        # sanity check for platforms to prevent obscure errors later.
        ok_plats = 'win32', 'win-amd64', 'win-ia64'
        if plat_name not in ok_plats:
            raise DistutilsPlatformError("--plat-name must be one of %s" %
                                         (ok_plats,))

        if "DISTUTILS_USE_SDK" in os.environ and "MSSdk" in os.environ and self.find_exe("cl.exe"):
            # Assume that the SDK set up everything alright; don't try to be
            # smarter
            self.cc = "cl.exe"
            self.linker = "link.exe"
            self.lib = "lib.exe"
            self.rc = "rc.exe"
            self.mc = "mc.exe"
        else:
            # On x86, 'vcvars32.bat amd64' creates an env that doesn't work;
            # to cross compile, you use 'x86_amd64'.
            # On AMD64, 'vcvars32.bat amd64' is a native build env; to cross
            # compile use 'x86' (ie, it runs the x86 compiler directly)
            # No idea how itanium handles this, if at all.
            if plat_name == get_platform() or plat_name == 'win32':
                # native build or cross-compile to win32
                plat_spec = PLAT_TO_VCVARS[plat_name]
            else:
                # cross compile from win32 -> some 64bit
                plat_spec = PLAT_TO_VCVARS[get_platform()] + '_' + \
                            PLAT_TO_VCVARS[plat_name]

            vc_env = query_vcvarsall(VERSION, plat_spec)

            # take care to only use strings in the environment.
            self.__paths = vc_env['path'].encode('mbcs').split(os.pathsep)
            os.environ['lib'] = vc_env['lib'].encode('mbcs')
            os.environ['include'] = vc_env['include'].encode('mbcs')

            if len(self.__paths) == 0:
                raise DistutilsPlatformError("Python was built with %s, "
                       "and extensions need to be built with the same "
                       "version of the compiler, but it isn't installed."
                       % self.__product)

            self.cc = self.find_exe("cl.exe")
            self.linker = self.find_exe("link.exe")
            self.lib = self.find_exe("lib.exe")
            self.rc = self.find_exe("rc.exe")   # resource compiler
            self.mc = self.find_exe("mc.exe")   # message compiler
            #self.set_path_env_var('lib')
            #self.set_path_env_var('include')

        # extend the MSVC path with the current path
        try:
            for p in os.environ['path'].split(';'):
                self.__paths.append(p)
        except KeyError:
            pass
        self.__paths = normalize_and_reduce_paths(self.__paths)
        os.environ['path'] = ";".join(self.__paths)

        self.preprocess_options = None
        if self.__arch == "x86":
            self.compile_options = [ '/nologo', '/Ox', '/MD', '/W3',
                                     '/DNDEBUG']
            self.compile_options_debug = ['/nologo', '/Od', '/MDd', '/W3',
                                          '/Z7', '/D_DEBUG']
        else:
            # Win64
            self.compile_options = [ '/nologo', '/Ox', '/MD', '/W3', '/GS-' ,
                                     '/DNDEBUG']
            self.compile_options_debug = ['/nologo', '/Od', '/MDd', '/W3', '/GS-',
                                          '/Z7', '/D_DEBUG']

        self.ldflags_shared = ['/DLL', '/nologo', '/INCREMENTAL:NO']
        if self.__version >= 7:
            self.ldflags_shared_debug = [
                '/DLL', '/nologo', '/INCREMENTAL:no', '/DEBUG'
                ]
        self.ldflags_static = [ '/nologo']

        self.initialized = True

    # -- Worker methods ------------------------------------------------

    def object_filenames(self,
                         source_filenames,
                         strip_dir=0,
                         output_dir=''):
        # Copied from ccompiler.py, extended to return .res as 'object'-file
        # for .rc input file
        if output_dir is None: output_dir = ''
        obj_names = []
        for src_name in source_filenames:
            (base, ext) = os.path.splitext (src_name)
            base = os.path.splitdrive(base)[1] # Chop off the drive
            base = base[os.path.isabs(base):]  # If abs, chop off leading /
            if ext not in self.src_extensions:
                # Better to raise an exception instead of silently continuing
                # and later complain about sources and targets having
                # different lengths
                raise CompileError ("Don't know how to compile %s" % src_name)
            if strip_dir:
                base = os.path.basename (base)
            if ext in self._rc_extensions:
                obj_names.append (os.path.join (output_dir,
                                                base + self.res_extension))
            elif ext in self._mc_extensions:
                obj_names.append (os.path.join (output_dir,
                                                base + self.res_extension))
            else:
                obj_names.append (os.path.join (output_dir,
                                                base + self.obj_extension))
        return obj_names


    def compile(self, sources,
                output_dir=None, macros=None, include_dirs=None, debug=0,
                extra_preargs=None, extra_postargs=None, depends=None):

        if not self.initialized:
            self.initialize()
        compile_info = self._setup_compile(output_dir, macros, include_dirs,
                                           sources, depends, extra_postargs)
        macros, objects, extra_postargs, pp_opts, build = compile_info

        compile_opts = extra_preargs or []
        compile_opts.append ('/c')
        if debug:
            compile_opts.extend(self.compile_options_debug)
        else:
            compile_opts.extend(self.compile_options)

        for obj in objects:
            try:
                src, ext = build[obj]
            except KeyError:
                continue
            if debug:
                # pass the full pathname to MSVC in debug mode,
                # this allows the debugger to find the source file
                # without asking the user to browse for it
                src = os.path.abspath(src)

            if ext in self._c_extensions:
                input_opt = "/Tc" + src
            elif ext in self._cpp_extensions:
                input_opt = "/Tp" + src
            elif ext in self._rc_extensions:
                # compile .RC to .RES file
                input_opt = src
                output_opt = "/fo" + obj
                try:
                    self.spawn([self.rc] + pp_opts +
                               [output_opt] + [input_opt])
                except DistutilsExecError, msg:
                    raise CompileError(msg)
                continue
            elif ext in self._mc_extensions:
                # Compile .MC to .RC file to .RES file.
                #   * '-h dir' specifies the directory for the
                #     generated include file
                #   * '-r dir' specifies the target directory of the
                #     generated RC file and the binary message resource
                #     it includes
                #
                # For now (since there are no options to change this),
                # we use the source-directory for the include file and
                # the build directory for the RC file and message
                # resources. This works at least for win32all.
                h_dir = os.path.dirname(src)
                rc_dir = os.path.dirname(obj)
                try:
                    # first compile .MC to .RC and .H file
                    self.spawn([self.mc] +
                               ['-h', h_dir, '-r', rc_dir] + [src])
                    base, _ = os.path.splitext (os.path.basename (src))
                    rc_file = os.path.join (rc_dir, base + '.rc')
                    # then compile .RC to .RES file
                    self.spawn([self.rc] +
                               ["/fo" + obj] + [rc_file])

                except DistutilsExecError, msg:
                    raise CompileError(msg)
                continue
            else:
                # how to handle this file?
                raise CompileError("Don't know how to compile %s to %s"
                                   % (src, obj))

            output_opt = "/Fo" + obj
            try:
                self.spawn([self.cc] + compile_opts + pp_opts +
                           [input_opt, output_opt] +
                           extra_postargs)
            except DistutilsExecError, msg:
                raise CompileError(msg)

        return objects


    def create_static_lib(self,
                          objects,
                          output_libname,
                          output_dir=None,
                          debug=0,
                          target_lang=None):

        if not self.initialized:
            self.initialize()
        (objects, output_dir) = self._fix_object_args(objects, output_dir)
        output_filename = self.library_filename(output_libname,
                                                output_dir=output_dir)

        if self._need_link(objects, output_filename):
            lib_args = objects + ['/OUT:' + output_filename]
            if debug:
                pass # XXX what goes here?
            try:
                self.spawn([self.lib] + lib_args)
            except DistutilsExecError, msg:
                raise LibError(msg)
        else:
            log.debug("skipping %s (up-to-date)", output_filename)


    def link(self,
             target_desc,
             objects,
             output_filename,
             output_dir=None,
             libraries=None,
             library_dirs=None,
             runtime_library_dirs=None,
             export_symbols=None,
             debug=0,
             extra_preargs=None,
             extra_postargs=None,
             build_temp=None,
             target_lang=None):

        if not self.initialized:
            self.initialize()
        (objects, output_dir) = self._fix_object_args(objects, output_dir)
        fixed_args = self._fix_lib_args(libraries, library_dirs,
                                        runtime_library_dirs)
        (libraries, library_dirs, runtime_library_dirs) = fixed_args

        if runtime_library_dirs:
            self.warn ("I don't know what to do with 'runtime_library_dirs': "
                       + str (runtime_library_dirs))

        lib_opts = gen_lib_options(self,
                                   library_dirs, runtime_library_dirs,
                                   libraries)
        if output_dir is not None:
            output_filename = os.path.join(output_dir, output_filename)

        if self._need_link(objects, output_filename):
            if target_desc == CCompiler.EXECUTABLE:
                if debug:
                    ldflags = self.ldflags_shared_debug[1:]
                else:
                    ldflags = self.ldflags_shared[1:]
            else:
                if debug:
                    ldflags = self.ldflags_shared_debug
                else:
                    ldflags = self.ldflags_shared

            export_opts = []
            for sym in (export_symbols or []):
                export_opts.append("/EXPORT:" + sym)

            ld_args = (ldflags + lib_opts + export_opts +
                       objects + ['/OUT:' + output_filename])

            # The MSVC linker generates .lib and .exp files, which cannot be
            # suppressed by any linker switches. The .lib files may even be
            # needed! Make sure they are generated in the temporary build
            # directory. Since they have different names for debug and release
            # builds, they can go into the same directory.
            build_temp = os.path.dirname(objects[0])
            if export_symbols is not None:
                (dll_name, dll_ext) = os.path.splitext(
                    os.path.basename(output_filename))
                implib_file = os.path.join(
                    build_temp,
                    self.library_filename(dll_name))
                ld_args.append ('/IMPLIB:' + implib_file)

            self.manifest_setup_ldargs(output_filename, build_temp, ld_args)

            if extra_preargs:
                ld_args[:0] = extra_preargs
            if extra_postargs:
                ld_args.extend(extra_postargs)

            self.mkpath(os.path.dirname(output_filename))
            try:
                self.spawn([self.linker] + ld_args)
            except DistutilsExecError, msg:
                raise LinkError(msg)

            # embed the manifest
            # XXX - this is somewhat fragile - if mt.exe fails, distutils
            # will still consider the DLL up-to-date, but it will not have a
            # manifest.  Maybe we should link to a temp file?  OTOH, that
            # implies a build environment error that shouldn't go undetected.
            mfinfo = self.manifest_get_embed_info(target_desc, ld_args)
            if mfinfo is not None:
                mffilename, mfid = mfinfo
                out_arg = '-outputresource:%s;%s' % (output_filename, mfid)
                try:
                    self.spawn(['mt.exe', '-nologo', '-manifest',
                                mffilename, out_arg])
                except DistutilsExecError, msg:
                    raise LinkError(msg)
        else:
            log.debug("skipping %s (up-to-date)", output_filename)

    def manifest_setup_ldargs(self, output_filename, build_temp, ld_args):
        # If we need a manifest at all, an embedded manifest is recommended.
        # See MSDN article titled
        # "How to: Embed a Manifest Inside a C/C++ Application"
        # (currently at http://msdn2.microsoft.com/en-us/library/ms235591(VS.80).aspx)
        # Ask the linker to generate the manifest in the temp dir, so
        # we can check it, and possibly embed it, later.
        temp_manifest = os.path.join(
                build_temp,
                os.path.basename(output_filename) + ".manifest")
        ld_args.append('/MANIFESTFILE:' + temp_manifest)

    def manifest_get_embed_info(self, target_desc, ld_args):
        # If a manifest should be embedded, return a tuple of
        # (manifest_filename, resource_id).  Returns None if no manifest
        # should be embedded.  See http://bugs.python.org/issue7833 for why
        # we want to avoid any manifest for extension modules if we can)
        for arg in ld_args:
            if arg.startswith("/MANIFESTFILE:"):
                temp_manifest = arg.split(":", 1)[1]
                break
        else:
            # no /MANIFESTFILE so nothing to do.
            return None
        if target_desc == CCompiler.EXECUTABLE:
            # by default, executables always get the manifest with the
            # CRT referenced.
            mfid = 1
        else:
            # Extension modules try and avoid any manifest if possible.
            mfid = 2
            temp_manifest = self._remove_visual_c_ref(temp_manifest)
        if temp_manifest is None:
            return None
        return temp_manifest, mfid

    def _remove_visual_c_ref(self, manifest_file):
        try:
            # Remove references to the Visual C runtime, so they will
            # fall through to the Visual C dependency of Python.exe.
            # This way, when installed for a restricted user (e.g.
            # runtimes are not in WinSxS folder, but in Python's own
            # folder), the runtimes do not need to be in every folder
            # with .pyd's.
            # Returns either the filename of the modified manifest or
            # None if no manifest should be embedded.
            manifest_f = open(manifest_file)
            try:
                manifest_buf = manifest_f.read()
            finally:
                manifest_f.close()
            pattern = re.compile(
                r"""<assemblyIdentity.*?name=("|')Microsoft\."""\
                r"""VC\d{2}\.CRT("|').*?(/>|</assemblyIdentity>)""",
                re.DOTALL)
            manifest_buf = re.sub(pattern, "", manifest_buf)
            pattern = "<dependentAssembly>\s*</dependentAssembly>"
            manifest_buf = re.sub(pattern, "", manifest_buf)
            # Now see if any other assemblies are referenced - if not, we
            # don't want a manifest embedded.
            pattern = re.compile(
                r"""<assemblyIdentity.*?name=(?:"|')(.+?)(?:"|')"""
                r""".*?(?:/>|</assemblyIdentity>)""", re.DOTALL)
            if re.search(pattern, manifest_buf) is None:
                return None

            manifest_f = open(manifest_file, 'w')
            try:
                manifest_f.write(manifest_buf)
                return manifest_file
            finally:
                manifest_f.close()
        except IOError:
            pass

    # -- Miscellaneous methods -----------------------------------------
    # These are all used by the 'gen_lib_options() function, in
    # ccompiler.py.

    def library_dir_option(self, dir):
        return "/LIBPATH:" + dir

    def runtime_library_dir_option(self, dir):
        raise DistutilsPlatformError(
              "don't know how to set runtime library search path for MSVC++")

    def library_option(self, lib):
        return self.library_filename(lib)


    def find_library_file(self, dirs, lib, debug=0):
        # Prefer a debugging library if found (and requested), but deal
        # with it if we don't have one.
        if debug:
            try_names = [lib + "_d", lib]
        else:
            try_names = [lib]
        for dir in dirs:
            for name in try_names:
                libfile = os.path.join(dir, self.library_filename (name))
                if os.path.exists(libfile):
                    return libfile
        else:
            # Oops, didn't find it in *any* of 'dirs'
            return None

    # Helper methods for using the MSVC registry settings

    def find_exe(self, exe):
        """Return path to an MSVC executable program.

        Tries to find the program in several places: first, one of the
        MSVC program search paths from the registry; next, the directories
        in the PATH environment variable.  If any of those work, return an
        absolute path that is known to exist.  If none of them work, just
        return the original program name, 'exe'.
        """
        for p in self.__paths:
            fn = os.path.join(os.path.abspath(p), exe)
            if os.path.isfile(fn):
                return fn

        # didn't find it; try existing path
        for p in os.environ['Path'].split(';'):
            fn = os.path.join(os.path.abspath(p),exe)
            if os.path.isfile(fn):
                return fn

        return exe