summaryrefslogtreecommitdiff
path: root/QMTest/TestSCons.py
blob: ff3c0a9a0f983c10814b6e75a82eff744041067f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
"""
TestSCons.py:  a testing framework for the SCons software construction
tool.

A TestSCons environment object is created via the usual invocation:

    test = TestSCons()

TestScons is a subclass of TestCommon, which in turn is a subclass
of TestCmd), and hence has available all of the methods and attributes
from those classes, as well as any overridden or additional methods or
attributes defined in this subclass.
"""

# Copyright (c) 2001 - 2015 The SCons Foundation
from __future__ import division

__revision__ = "QMTest/TestSCons.py rel_2.4.0:3365:9259ea1c13d7 2015/09/21 14:03:43 bdbaddog"

import os
import re
import shutil
import sys
import time

from TestCommon import *
from TestCommon import __all__

from TestCmd import Popen
from TestCmd import PIPE

# Some tests which verify that SCons has been packaged properly need to
# look for specific version file names.  Replicating the version number
# here provides some independent verification that what we packaged
# conforms to what we expect.

default_version = '2.4.0'

python_version_unsupported = (2, 3, 0)
python_version_deprecated = (2, 7, 0)

# In the checked-in source, the value of SConsVersion in the following
# line must remain "__ VERSION __" (without the spaces) so the built
# version in build/QMTest/TestSCons.py contains the actual version
# string of the packages that have been built.
SConsVersion = '2.4.0'
if SConsVersion == '__' + 'VERSION' + '__':
    SConsVersion = default_version

__all__.extend([ 'TestSCons',
                 'machine',
                 'python',
                 '_exe',
                 '_obj',
                 '_shobj',
                 'shobj_',
                 'lib_',
                 '_lib',
                 'dll_',
                 '_dll'
               ])

machine_map = {
    'i686'  : 'i386',
    'i586'  : 'i386',
    'i486'  : 'i386',
}

try:
    uname = os.uname
except AttributeError:
    # Windows doesn't have a uname() function.  We could use something like
    # sys.platform as a fallback, but that's not really a "machine," so
    # just leave it as None.
    machine = None
else:
    machine = uname()[4]
    machine = machine_map.get(machine, machine)

_exe = exe_suffix
_obj = obj_suffix
_shobj = shobj_suffix
shobj_ = shobj_prefix
_lib = lib_suffix
lib_ = lib_prefix
_dll = dll_suffix
dll_ = dll_prefix


if sys.platform == 'cygwin':
    # On Cygwin, os.path.normcase() lies, so just report back the
    # fact that the underlying Win32 OS is case-insensitive.
    def case_sensitive_suffixes(s1, s2):
        return 0
else:
    def case_sensitive_suffixes(s1, s2):
        return (os.path.normcase(s1) != os.path.normcase(s2))


file_expr = r"""File "[^"]*", line \d+, in [^\n]+
"""

# re.escape escapes too much.
def re_escape(str):
    for c in '\\.[]()*+?':   # Not an exhaustive list.
        str = str.replace(c, '\\' + c)
    return str

#
# Helper functions that we use as a replacement to the default re.match
# when searching for special strings in stdout/stderr.
#
def search_re(out, l):
    """ Search the regular expression 'l' in the output 'out'
        and return the start index when successful.
    """
    m = re.search(l, out)
    if m:
        return m.start()

    return None

def search_re_in_list(out, l):
    """ Search the regular expression 'l' in each line of
        the given string list 'out' and return the line's index
        when successful.
    """
    for idx, o in enumerate(out):
        m = re.search(l, o)
        if m:
            return idx

    return None

#
# Helpers for handling Python version numbers
#
def python_version_string():
    return sys.version.split()[0]

def python_minor_version_string():
    return sys.version[:3]

def unsupported_python_version(version=sys.version_info):
    return version < python_version_unsupported

def deprecated_python_version(version=sys.version_info):
    return version < python_version_deprecated

if deprecated_python_version():
    msg = r"""
scons: warning: Support for pre-2.7.0 Python version (%s) is deprecated.
    If this will cause hardship, contact scons-dev@scons.org
"""

    deprecated_python_expr = re_escape(msg % python_version_string()) + file_expr
    del msg
else:
    deprecated_python_expr = ""


def initialize_sconsflags(ignore_python_version):
    """
    Add the --warn=no-python-version option to SCONSFLAGS for every
    command so test scripts don't have to filter out Python version
    deprecation warnings.
    Same for --warn=no-visual-c-missing.
    """
    save_sconsflags = os.environ.get('SCONSFLAGS')
    if save_sconsflags:
        sconsflags = [save_sconsflags]
    else:
        sconsflags = []
    if ignore_python_version and deprecated_python_version():
        sconsflags.append('--warn=no-python-version')
    # Provide a way to suppress or provide alternate flags for
    # TestSCons purposes by setting TESTSCONS_SCONSFLAGS.
    # (The intended use case is to set it to null when running
    # timing tests of earlier versions of SCons which don't
    # support the --warn=no-visual-c-missing warning.)
    visual_c = os.environ.get('TESTSCONS_SCONSFLAGS',
                              '--warn=no-visual-c-missing')
    if visual_c:
        sconsflags.append(visual_c)
    os.environ['SCONSFLAGS'] = ' '.join(sconsflags)
    return save_sconsflags

def restore_sconsflags(sconsflags):
    if sconsflags is None:
        del os.environ['SCONSFLAGS']
    else:
        os.environ['SCONSFLAGS'] = sconsflags


class TestSCons(TestCommon):
    """Class for testing SCons.

    This provides a common place for initializing SCons tests,
    eliminating the need to begin every test with the same repeated
    initializations.
    """

    scons_version = SConsVersion

    def __init__(self, **kw):
        """Initialize an SCons testing object.

        If they're not overridden by keyword arguments, this
        initializes the object with the following default values:

                program = 'scons' if it exists,
                          else 'scons.py'
                interpreter = 'python'
                match = match_exact
                workdir = ''

        The workdir value means that, by default, a temporary workspace
        directory is created for a TestSCons environment.  In addition,
        this method changes directory (chdir) to the workspace directory,
        so an explicit "chdir = '.'" on all of the run() method calls
        is not necessary.
        """
        self.orig_cwd = os.getcwd()
        self.external = os.environ.get('SCONS_EXTERNAL_TEST', 0)

        if not self.external:
            try:
                script_dir = os.environ['SCONS_SCRIPT_DIR']
            except KeyError:
                pass
            else:
                os.chdir(script_dir)
        if 'program' not in kw:
            kw['program'] = os.environ.get('SCONS')
            if not kw['program']:
                if not self.external:
                    if os.path.exists('scons'):
                        kw['program'] = 'scons'
                    else:
                        kw['program'] = 'scons.py'
                else:
                    kw['program'] = 'scons'
                    kw['interpreter'] = ''
            elif not self.external and not os.path.isabs(kw['program']):
                kw['program'] = os.path.join(self.orig_cwd, kw['program'])
        if 'interpreter' not in kw and not os.environ.get('SCONS_EXEC'):
            kw['interpreter'] = [python, '-tt']
        if 'match' not in kw:
            kw['match'] = match_exact
        if 'workdir' not in kw:
            kw['workdir'] = ''

        # Term causing test failures due to bogus readline init
        # control character output on FC8
        # TERM can cause test failures due to control chars in prompts etc.
        os.environ['TERM'] = 'dumb'

        self.ignore_python_version = kw.get('ignore_python_version',1)
        if kw.get('ignore_python_version', -1) != -1:
            del kw['ignore_python_version']

        TestCommon.__init__(self, **kw)

        if not self.external:
            import SCons.Node.FS
            if SCons.Node.FS.default_fs is None:
                SCons.Node.FS.default_fs = SCons.Node.FS.FS()

        try:
            self.script_srcdir = os.environ['PYTHON_SCRIPT_DIR']
        except KeyError:
            pass

    def Environment(self, ENV=None, *args, **kw):
        """
        Return a construction Environment that optionally overrides
        the default external environment with the specified ENV.
        """
        if not self.external:
            import SCons.Environment
            import SCons.Errors
            if not ENV is None:
                kw['ENV'] = ENV
            try:
                return SCons.Environment.Environment(*args, **kw)
            except (SCons.Errors.UserError, SCons.Errors.InternalError):
                return None

        return None

    def detect(self, var, prog=None, ENV=None, norm=None):
        """
        Detect a program named 'prog' by first checking the construction
        variable named 'var' and finally searching the path used by
        SCons. If either method fails to detect the program, then false
        is returned, otherwise the full path to prog is returned. If
        prog is None, then the value of the environment variable will be
        used as prog.
        """
        env = self.Environment(ENV)
        if env:
            v = env.subst('$'+var)
            if not v:
                return None
            if prog is None:
                prog = v
            if v != prog:
                return None
            result = env.WhereIs(prog)
            if norm and os.sep != '/':
                result = result.replace(os.sep, '/')
            return result

        return self.where_is(prog)

    def detect_tool(self, tool, prog=None, ENV=None):
        """
        Given a tool (i.e., tool specification that would be passed
        to the "tools=" parameter of Environment()) and a program that
        corresponds to that tool, return true if and only if we can find
        that tool using Environment.Detect().

        By default, prog is set to the value passed into the tools parameter.
        """

        if not prog:
            prog = tool
        env = self.Environment(ENV, tools=[tool])
        if env is None:
            return None
        return env.Detect([prog])

    def where_is(self, prog, path=None):
        """
        Given a program, search for it in the specified external PATH,
        or in the actual external PATH if none is specified.
        """
        if path is None:
            path = os.environ['PATH']
        if self.external:
            if isinstance(prog, str):
                prog = [prog]
            import stat
            paths = path.split(os.pathsep)
            for p in prog:
                for d in paths:
                    f = os.path.join(d, p)
                    if os.path.isfile(f):
                        try:
                            st = os.stat(f)
                        except OSError:
                            # os.stat() raises OSError, not IOError if the file
                            # doesn't exist, so in this case we let IOError get
                            # raised so as to not mask possibly serious disk or
                            # network issues.
                            continue
                        if stat.S_IMODE(st[stat.ST_MODE]) & 0111:
                            return os.path.normpath(f)
        else:
            import SCons.Environment
            env = SCons.Environment.Environment()
            return env.WhereIs(prog, path)

        return None

    def wrap_stdout(self, build_str = "", read_str = "", error = 0, cleaning = 0):
        """Wraps standard output string(s) in the normal
        "Reading ... done" and "Building ... done" strings
        """
        cap,lc = [ ('Build','build'),
                   ('Clean','clean') ][cleaning]
        if error:
            term = "scons: %sing terminated because of errors.\n" % lc
        else:
            term = "scons: done %sing targets.\n" % lc
        return "scons: Reading SConscript files ...\n" + \
               read_str + \
               "scons: done reading SConscript files.\n" + \
               "scons: %sing targets ...\n" % cap + \
               build_str + \
               term

    def run(self, *args, **kw):
        """
        Set up SCONSFLAGS for every command so test scripts don't need
        to worry about unexpected warnings in their output.
        """
        sconsflags = initialize_sconsflags(self.ignore_python_version)
        try:
            TestCommon.run(self, *args, **kw)
        finally:
            restore_sconsflags(sconsflags)

# Modifying the options should work and ought to be simpler, but this
# class is used for more than just running 'scons' itself.  If there's
# an automated  way of determining whether it's running 'scons' or
# something else, this code should be resurected.
#        options = kw.get('options')
#        if options:
#            options = [options]
#        else:
#            options = []
#        if self.ignore_python_version and deprecated_python_version():
#            options.append('--warn=no-python-version')
#        # Provide a way to suppress or provide alternate flags for
#        # TestSCons purposes by setting TESTSCONS_SCONSFLAGS.
#        # (The intended use case is to set it to null when running
#        # timing tests of earlier versions of SCons which don't
#        # support the --warn=no-visual-c-missing warning.)
#        visual_c = os.environ.get('TESTSCONS_SCONSFLAGS',
#                                      '--warn=no-visual-c-missing')
#        if visual_c:
#            options.append(visual_c)
#        kw['options'] = ' '.join(options)
#        TestCommon.run(self, *args, **kw)

    def up_to_date(self, arguments = '.', read_str = "", **kw):
        s = ""
        for arg in arguments.split():
            s = s + "scons: `%s' is up to date.\n" % arg
        kw['arguments'] = arguments
        stdout = self.wrap_stdout(read_str = read_str, build_str = s)
        # Append '.*' so that timing output that comes after the
        # up-to-date output is okay.
        kw['stdout'] = re.escape(stdout) + '.*'
        kw['match'] = self.match_re_dotall
        self.run(**kw)

    def not_up_to_date(self, arguments = '.', **kw):
        """Asserts that none of the targets listed in arguments is
        up to date, but does not make any assumptions on other targets.
        This function is most useful in conjunction with the -n option.
        """
        s = ""
        for arg in arguments.split():
            s = s + "(?!scons: `%s' is up to date.)" % re.escape(arg)
        s = '('+s+'[^\n]*\n)*'
        kw['arguments'] = arguments
        stdout = re.escape(self.wrap_stdout(build_str='ARGUMENTSGOHERE'))
        kw['stdout'] = stdout.replace('ARGUMENTSGOHERE', s)
        kw['match'] = self.match_re_dotall
        self.run(**kw)

    def option_not_yet_implemented(self, option, arguments=None, **kw):
        """
        Verifies expected behavior for options that are not yet implemented:
        a warning message, and exit status 1.
        """
        msg = "Warning:  the %s option is not yet implemented\n" % option
        kw['stderr'] = msg
        if arguments:
            # If it's a long option and the argument string begins with '=',
            # it's of the form --foo=bar and needs no separating space.
            if option[:2] == '--' and arguments[0] == '=':
                kw['arguments'] = option + arguments
            else:
                kw['arguments'] = option + ' ' + arguments
        return self.run(**kw)

    def deprecated_wrap(self, msg):
        """
        Calculate the pattern that matches a deprecation warning.
        """
        return '\nscons: warning: ' + re_escape(msg) + '\n' + file_expr

    def deprecated_fatal(self, warn, msg):
        """
        Determines if the warning has turned into a fatal error.  If so,
        passes the test, as any remaining runs are now moot.

        This method expects a SConscript to be present that will causes
        the warning.  The method writes a SConstruct that calls the
        SConsscript and looks to see what type of result occurs.

        The pattern that matches the warning is returned.

        TODO: Actually detect that it's now an error.  We don't have any
        cases yet, so there's no way to test it.
        """
        self.write('SConstruct', """if True:
            WARN = ARGUMENTS.get('WARN')
            if WARN: SetOption('warn', WARN)
            SConscript('SConscript')
        """)

        def err_out():
            # TODO calculate stderr for fatal error
            return re_escape('put something here')

        # no option, should get one of nothing, warning, or error
        warning = self.deprecated_wrap(msg)
        self.run(arguments = '.', stderr = None)
        stderr = self.stderr()
        if stderr:
            # most common case done first
            if match_re_dotall(stderr, warning):
               # expected output
               pass
            elif match_re_dotall(stderr, err_out()):
               # now a fatal error; skip the rest of the tests
               self.pass_test()
            else:
               # test failed; have to do this by hand...
               print self.banner('STDOUT ')
               print self.stdout()
               print self.diff(warning, stderr, 'STDERR ')
               self.fail_test()

        return warning

    def deprecated_warning(self, warn, msg):
        """
        Verifies the expected behavior occurs for deprecation warnings.
        This method expects a SConscript to be present that will causes
        the warning.  The method writes a SConstruct and exercises various
        combinations of command-line options and SetOption parameters to
        validate that it performs correctly.

        The pattern that matches the warning is returned.
        """
        warning = self.deprecated_fatal(warn, msg)

        def RunPair(option, expected):
            # run the same test with the option on the command line and
            # then with the option passed via SetOption().
            self.run(options = '--warn=' + option,
                     arguments = '.',
                     stderr = expected,
                     match = match_re_dotall)
            self.run(options = 'WARN=' + option,
                     arguments = '.',
                     stderr = expected,
                     match = match_re_dotall)

        # all warnings off, should get no output
        RunPair('no-deprecated', '')

        # warning enabled, should get expected output
        RunPair(warn, warning)

        # warning disabled, should get either nothing or mandatory message
        expect = """()|(Can not disable mandataory warning: 'no-%s'\n\n%s)""" % (warn, warning)
        RunPair('no-' + warn, expect)

        return warning

    def diff_substr(self, expect, actual, prelen=20, postlen=40):
        i = 0
        for x, y in zip(expect, actual):
            if x != y:
                return "Actual did not match expect at char %d:\n" \
                       "    Expect:  %s\n" \
                       "    Actual:  %s\n" \
                       % (i, repr(expect[i-prelen:i+postlen]),
                             repr(actual[i-prelen:i+postlen]))
            i = i + 1
        return "Actual matched the expected output???"

    def python_file_line(self, file, line):
        """
        Returns a Python error line for output comparisons.

        The exec of the traceback line gives us the correct format for
        this version of Python.  Before 2.5, this yielded:

            File "<string>", line 1, ?

        Python 2.5 changed this to:

            File "<string>", line 1, <module>

        We stick the requested file name and line number in the right
        places, abstracting out the version difference.
        """
        exec 'import traceback; x = traceback.format_stack()[-1]'
        x = x.lstrip()
        x = x.replace('<string>', file)
        x = x.replace('line 1,', 'line %s,' % line)
        return x

    def normalize_ps(self, s):
        s = re.sub(r'(Creation|Mod)Date: .*',
                   r'\1Date XXXX', s)
        s = re.sub(r'%DVIPSSource:\s+TeX output\s.*',
                   r'%DVIPSSource:   TeX output XXXX', s)
        s = re.sub(r'/(BaseFont|FontName) /[A-Z0-9]{6}',
                   r'/\1 /XXXXXX', s)
        s = re.sub(r'BeginFont: [A-Z0-9]{6}',
                   r'BeginFont: XXXXXX', s)

        return s

    def normalize_pdf(self, s):
        s = re.sub(r'/(Creation|Mod)Date \(D:[^)]*\)',
                   r'/\1Date (D:XXXX)', s)
        s = re.sub(r'/ID \[<[0-9a-fA-F]*> <[0-9a-fA-F]*>\]',
                   r'/ID [<XXXX> <XXXX>]', s)
        s = re.sub(r'/(BaseFont|FontName) /[A-Z]{6}',
                   r'/\1 /XXXXXX', s)
        s = re.sub(r'/Length \d+ *\n/Filter /FlateDecode\n',
                   r'/Length XXXX\n/Filter /FlateDecode\n', s)

        try:
            import zlib
        except ImportError:
            pass
        else:
            begin_marker = '/FlateDecode\n>>\nstream\n'
            end_marker = 'endstream\nendobj'

            encoded = []
            b = s.find(begin_marker, 0)
            while b != -1:
                b = b + len(begin_marker)
                e = s.find(end_marker, b)
                encoded.append((b, e))
                b = s.find(begin_marker, e + len(end_marker))

            x = 0
            r = []
            for b, e in encoded:
                r.append(s[x:b])
                d = zlib.decompress(s[b:e])
                d = re.sub(r'%%CreationDate: [^\n]*\n',
                           r'%%CreationDate: 1970 Jan 01 00:00:00\n', d)
                d = re.sub(r'%DVIPSSource:  TeX output \d\d\d\d\.\d\d\.\d\d:\d\d\d\d',
                           r'%DVIPSSource:  TeX output 1970.01.01:0000', d)
                d = re.sub(r'/(BaseFont|FontName) /[A-Z]{6}',
                           r'/\1 /XXXXXX', d)
                r.append(d)
                x = e
            r.append(s[x:])
            s = ''.join(r)

        return s

    def paths(self,patterns):
        import glob
        result = []
        for p in patterns:
            result.extend(sorted(glob.glob(p)))
        return result


    def java_ENV(self, version=None):
        """
        Initialize with a default external environment that uses a local
        Java SDK in preference to whatever's found in the default PATH.
        """
        if not self.external:
            try:
                return self._java_env[version]['ENV']
            except AttributeError:
                self._java_env = {}
            except KeyError:
                pass

            import SCons.Environment
            env = SCons.Environment.Environment()
            self._java_env[version] = env


            if version:
                patterns = [
                    '/usr/java/jdk%s*/bin'    % version,
                    '/usr/lib/jvm/*-%s*/bin' % version,
                    '/usr/local/j2sdk%s*/bin' % version,
                ]
                java_path = self.paths(patterns) + [env['ENV']['PATH']]
            else:
                patterns = [
                    '/usr/java/latest/bin',
                    '/usr/lib/jvm/*/bin',
                    '/usr/local/j2sdk*/bin',
                ]
                java_path = self.paths(patterns) + [env['ENV']['PATH']]

            env['ENV']['PATH'] = os.pathsep.join(java_path)
            return env['ENV']

        return None

    def java_where_includes(self,version=None):
        """
        Return java include paths compiling java jni code
        """
        import glob
        import sys
        if not version:
            version=''
            jni_dirs = ['/System/Library/Frameworks/JavaVM.framework/Headers/jni.h',
                        '/usr/lib/jvm/default-java/include/jni.h']
        else:
            jni_dirs = ['/System/Library/Frameworks/JavaVM.framework/Versions/%s*/Headers/jni.h'%version]
        jni_dirs.extend(['/usr/lib/jvm/java-*-sun-%s*/include/jni.h'%version,
                         '/usr/lib/jvm/java-%s*-openjdk*/include/jni.h'%version,
                         '/usr/java/jdk%s*/include/jni.h'%version])
        dirs = self.paths(jni_dirs)
        if not dirs:
            return None
        d=os.path.dirname(self.paths(jni_dirs)[0])
        result=[d]

        if sys.platform == 'win32':
            result.append(os.path.join(d,'win32'))
        elif sys.platform.startswith('linux'):
            result.append(os.path.join(d,'linux'))
        return result


    def java_where_java_home(self,version=None):
        if sys.platform[:6] == 'darwin':
            if version is None:
                home = '/System/Library/Frameworks/JavaVM.framework/Home'
            else:
                home = '/System/Library/Frameworks/JavaVM.framework/Versions/%s/Home' % version
        else:
            jar = self.java_where_jar(version)
            home = os.path.normpath('%s/..'%jar)
        if os.path.isdir(home):
            return home
        print("Could not determine JAVA_HOME: %s is not a directory" % home)
        self.fail_test()

    def java_where_jar(self, version=None):
        ENV = self.java_ENV(version)
        if self.detect_tool('jar', ENV=ENV):
            where_jar = self.detect('JAR', 'jar', ENV=ENV)
        else:
            where_jar = self.where_is('jar', ENV['PATH'])
        if not where_jar:
            self.skip_test("Could not find Java jar, skipping test(s).\n")
        return where_jar

    def java_where_java(self, version=None):
        """
        Return a path to the java executable.
        """
        ENV = self.java_ENV(version)
        where_java = self.where_is('java', ENV['PATH'])
        if not where_java:
            self.skip_test("Could not find Java java, skipping test(s).\n")
        return where_java

    def java_where_javac(self, version=None):
        """
        Return a path to the javac compiler.
        """
        ENV = self.java_ENV(version)
        if self.detect_tool('javac'):
            where_javac = self.detect('JAVAC', 'javac', ENV=ENV)
        else:
            where_javac = self.where_is('javac', ENV['PATH'])
        if not where_javac:
            self.skip_test("Could not find Java javac, skipping test(s).\n")
        self.run(program = where_javac,
                 arguments = '-version',
                 stderr=None,
                 status=None)
        if version:
            if self.stderr().find('javac %s' % version) == -1:
                fmt = "Could not find javac for Java version %s, skipping test(s).\n"
                self.skip_test(fmt % version)
        else:
            m = re.search(r'javac (\d\.\d)', self.stderr())
            if m:
                version = m.group(1)
            else:
                version = None
        return where_javac, version

    def java_where_javah(self, version=None):
        ENV = self.java_ENV(version)
        if self.detect_tool('javah'):
            where_javah = self.detect('JAVAH', 'javah', ENV=ENV)
        else:
            where_javah = self.where_is('javah', ENV['PATH'])
        if not where_javah:
            self.skip_test("Could not find Java javah, skipping test(s).\n")
        return where_javah

    def java_where_rmic(self, version=None):
        ENV = self.java_ENV(version)
        if self.detect_tool('rmic'):
            where_rmic = self.detect('RMIC', 'rmic', ENV=ENV)
        else:
            where_rmic = self.where_is('rmic', ENV['PATH'])
        if not where_rmic:
            self.skip_test("Could not find Java rmic, skipping non-simulated test(s).\n")
        return where_rmic

    def java_get_class_files(self, dir):
        result = []
        for dirpath, dirnames, filenames in os.walk(dir):
            for fname in filenames:
                if fname.endswith('.class'):
                    result.append(os.path.join(dirpath, fname))
        return sorted(result)


    def Qt_dummy_installation(self, dir='qt'):
        # create a dummy qt installation

        self.subdir( dir, [dir, 'bin'], [dir, 'include'], [dir, 'lib'] )

        self.write([dir, 'bin', 'mymoc.py'], """\
import getopt
import sys
import re
# -w and -z are fake options used in test/QT/QTFLAGS.py
cmd_opts, args = getopt.getopt(sys.argv[1:], 'io:wz', [])
output = None
impl = 0
opt_string = ''
for opt, arg in cmd_opts:
    if opt == '-o': output = open(arg, 'wb')
    elif opt == '-i': impl = 1
    else: opt_string = opt_string + ' ' + opt
output.write("/* mymoc.py%s */\\n" % opt_string)
for a in args:
    contents = open(a, 'rb').read()
    a = a.replace('\\\\', '\\\\\\\\')
    subst = r'{ my_qt_symbol( "' + a + '\\\\n" ); }'
    if impl:
        contents = re.sub( r'#include.*', '', contents )
    output.write(contents.replace('Q_OBJECT', subst))
output.close()
sys.exit(0)
""")

        self.write([dir, 'bin', 'myuic.py'], """\
import os.path
import re
import sys
output_arg = 0
impl_arg = 0
impl = None
source = None
opt_string = ''
for arg in sys.argv[1:]:
    if output_arg:
        output = open(arg, 'wb')
        output_arg = 0
    elif impl_arg:
        impl = arg
        impl_arg = 0
    elif arg == "-o":
        output_arg = 1
    elif arg == "-impl":
        impl_arg = 1
    elif arg[0:1] == "-":
        opt_string = opt_string + ' ' + arg
    else:
        if source:
            sys.exit(1)
        source = open(arg, 'rb')
        sourceFile = arg
output.write("/* myuic.py%s */\\n" % opt_string)
if impl:
    output.write( '#include "' + impl + '"\\n' )
    includes = re.findall('<include.*?>(.*?)</include>', source.read())
    for incFile in includes:
        # this is valid for ui.h files, at least
        if os.path.exists(incFile):
            output.write('#include "' + incFile + '"\\n')
else:
    output.write( '#include "my_qobject.h"\\n' + source.read() + " Q_OBJECT \\n" )
output.close()
sys.exit(0)
""" )

        self.write([dir, 'include', 'my_qobject.h'], r"""
#define Q_OBJECT ;
void my_qt_symbol(const char *arg);
""")

        self.write([dir, 'lib', 'my_qobject.cpp'], r"""
#include "../include/my_qobject.h"
#include <stdio.h>
void my_qt_symbol(const char *arg) {
  fputs( arg, stdout );
}
""")

        self.write([dir, 'lib', 'SConstruct'], r"""
env = Environment()
import sys
if sys.platform == 'win32':
    env.StaticLibrary( 'myqt', 'my_qobject.cpp' )
else:
    env.SharedLibrary( 'myqt', 'my_qobject.cpp' )
""")

        self.run(chdir = self.workpath(dir, 'lib'),
                 arguments = '.',
                 stderr = noisy_ar,
                 match = self.match_re_dotall)

        self.QT = self.workpath(dir)
        self.QT_LIB = 'myqt'
        self.QT_MOC = '%s %s' % (_python_, self.workpath(dir, 'bin', 'mymoc.py'))
        self.QT_UIC = '%s %s' % (_python_, self.workpath(dir, 'bin', 'myuic.py'))
        self.QT_LIB_DIR = self.workpath(dir, 'lib')

    def Qt_create_SConstruct(self, place):
        if isinstance(place, list):
            place = test.workpath(*place)
        self.write(place, """\
if ARGUMENTS.get('noqtdir', 0): QTDIR=None
else: QTDIR=r'%s'
env = Environment(QTDIR = QTDIR,
                  QT_LIB = r'%s',
                  QT_MOC = r'%s',
                  QT_UIC = r'%s',
                  tools=['default','qt'])
dup = 1
if ARGUMENTS.get('variant_dir', 0):
    if ARGUMENTS.get('chdir', 0):
        SConscriptChdir(1)
    else:
        SConscriptChdir(0)
    dup=int(ARGUMENTS.get('dup', 1))
    if dup == 0:
        builddir = 'build_dup0'
        env['QT_DEBUG'] = 1
    else:
        builddir = 'build'
    VariantDir(builddir, '.', duplicate=dup)
    print builddir, dup
    sconscript = Dir(builddir).File('SConscript')
else:
    sconscript = File('SConscript')
Export("env dup")
SConscript( sconscript )
""" % (self.QT, self.QT_LIB, self.QT_MOC, self.QT_UIC))


    NCR = 0 # non-cached rebuild
    CR  = 1 # cached rebuild (up to date)
    NCF = 2 # non-cached build failure
    CF  = 3 # cached build failure

    if sys.platform == 'win32':
        Configure_lib = 'msvcrt'
    else:
        Configure_lib = 'm'

    # to use cygwin compilers on cmd.exe -> uncomment following line
    #Configure_lib = 'm'

    def gccFortranLibs(self):
        """Test which gcc Fortran startup libraries are required.
        This should probably move into SCons itself, but is kind of hacky.
        """
        if sys.platform.find('irix') != -1:
            return ['ftn']

        libs = ['g2c']
        cmd = ['gcc','-v']

        try:
            p = Popen(cmd, stdout=PIPE, stderr=PIPE)
            stdout, stderr = p.communicate()
        except:
            return libs

        m = re.search('(gcc\s+version|gcc-Version)\s+(\d\.\d)', stderr)
        if m:
            gcc_version = m.group(2)
            if re.match('4.[^0]', gcc_version):
                libs = ['gfortranbegin']
            elif gcc_version in ('3.1', '4.0'):
                libs = ['frtbegin'] + libs

        return libs

    def skip_if_not_msvc(self, check_platform=True):
        """ Check whether we are on a Windows platform and skip the
            test if not. This check can be omitted by setting
            check_platform to False.
            Then, for a win32 platform, additionally check
            whether we have a MSVC toolchain installed
            in the system, and skip the test if none can be
            found (=MinGW is the only compiler available).
        """
        if check_platform:
            if sys.platform != 'win32':
                msg = "Skipping Visual C/C++ test on non-Windows platform '%s'\n" % sys.platform
                self.skip_test(msg)
                return

        try:
            import SCons.Tool.MSCommon as msc
            if not msc.msvc_exists():
                msg = "No MSVC toolchain found...skipping test\n"
                self.skip_test(msg)
        except:
            pass

    def checkLogAndStdout(self, checks, results, cached,
                          logfile, sconf_dir, sconstruct,
                          doCheckLog=1, doCheckStdout=1):

        class NoMatch(Exception):
            def __init__(self, p):
                self.pos = p

        def matchPart(log, logfile, lastEnd, NoMatch=NoMatch):
            m = re.match(log, logfile[lastEnd:])
            if not m:
                raise NoMatch(lastEnd)
            return m.end() + lastEnd
        try:
            #print len(os.linesep)
            ls = os.linesep
            nols = "("
            for i in range(len(ls)):
                nols = nols + "("
                for j in range(i):
                    nols = nols + ls[j]
                nols = nols + "[^" + ls[i] + "])"
                if i < len(ls)-1:
                    nols = nols + "|"
            nols = nols + ")"
            lastEnd = 0
            logfile = self.read(self.workpath(logfile))
            if (doCheckLog and
                logfile.find( "scons: warning: The stored build "
                             "information has an unexpected class." ) >= 0):
                self.fail_test()
            sconf_dir = sconf_dir
            sconstruct = sconstruct

            log = r'file\ \S*%s\,line \d+:' % re.escape(sconstruct) + ls
            if doCheckLog: lastEnd = matchPart(log, logfile, lastEnd)
            log = "\t" + re.escape("Configure(confdir = %s)" % sconf_dir) + ls
            if doCheckLog: lastEnd = matchPart(log, logfile, lastEnd)
            rdstr = ""
            cnt = 0
            for check,result,cache_desc in zip(checks, results, cached):
                log   = re.escape("scons: Configure: " + check) + ls
                if doCheckLog: lastEnd = matchPart(log, logfile, lastEnd)
                log = ""
                result_cached = 1
                for bld_desc in cache_desc: # each TryXXX
                    for ext, flag in bld_desc: # each file in TryBuild
                        file = os.path.join(sconf_dir,"conftest_%d%s" % (cnt, ext))
                        if flag == self.NCR:
                            # rebuild will pass
                            if ext in ['.c', '.cpp']:
                                log=log + re.escape(file + " <-") + ls
                                log=log + r"(  \|" + nols + "*" + ls + ")+?"
                            else:
                                log=log + "(" + nols + "*" + ls +")*?"
                            result_cached = 0
                        if flag == self.CR:
                            # up to date
                            log=log + \
                                 re.escape("scons: Configure: \"%s\" is up to date."
                                           % file) + ls
                            log=log+re.escape("scons: Configure: The original builder "
                                              "output was:") + ls
                            log=log+r"(  \|.*"+ls+")+"
                        if flag == self.NCF:
                            # non-cached rebuild failure
                            log=log + "(" + nols + "*" + ls + ")*?"
                            result_cached = 0
                        if flag == self.CF:
                            # cached rebuild failure
                            log=log + \
                                 re.escape("scons: Configure: Building \"%s\" failed "
                                           "in a previous run and all its sources are"
                                           " up to date." % file) + ls
                            log=log+re.escape("scons: Configure: The original builder "
                                              "output was:") + ls
                            log=log+r"(  \|.*"+ls+")+"
                    cnt = cnt + 1
                if result_cached:
                    result = "(cached) " + result
                rdstr = rdstr + re.escape(check) + re.escape(result) + "\n"
                log=log + re.escape("scons: Configure: " + result) + ls + ls
                if doCheckLog: lastEnd = matchPart(log, logfile, lastEnd)
                log = ""
            if doCheckLog: lastEnd = matchPart(ls, logfile, lastEnd)
            if doCheckLog and lastEnd != len(logfile):
                raise NoMatch(lastEnd)

        except NoMatch, m:
            print "Cannot match log file against log regexp."
            print "log file: "
            print "------------------------------------------------------"
            print logfile[m.pos:]
            print "------------------------------------------------------"
            print "log regexp: "
            print "------------------------------------------------------"
            print log
            print "------------------------------------------------------"
            self.fail_test()

        if doCheckStdout:
            exp_stdout = self.wrap_stdout(".*", rdstr)
            if not self.match_re_dotall(self.stdout(), exp_stdout):
                print "Unexpected stdout: "
                print "-----------------------------------------------------"
                print repr(self.stdout())
                print "-----------------------------------------------------"
                print repr(exp_stdout)
                print "-----------------------------------------------------"
                self.fail_test()

    def get_python_version(self):
        """
        Returns the Python version (just so everyone doesn't have to
        hand-code slicing the right number of characters).
        """
        # see also sys.prefix documentation
        return python_minor_version_string()

    def get_platform_python_info(self):
        """
        Returns a path to a Python executable suitable for testing on
        this platform and its associated include path, library path,
        and library name.
        """
        python = self.where_is('python')
        if not python:
            self.skip_test('Can not find installed "python", skipping test.\n')

        self.run(program = python, stdin = """\
import os, sys
try:
    if sys.platform == 'win32':
        py_ver = 'python%d%d' % sys.version_info[:2]
    else:
        py_ver = 'python%d.%d' % sys.version_info[:2]
except AttributeError:
    py_ver = 'python' + sys.version[:3]
# print include and lib path
try:
    import distutils.sysconfig
    exec_prefix = distutils.sysconfig.EXEC_PREFIX
    print distutils.sysconfig.get_python_inc()
    print os.path.join(exec_prefix, 'libs')
except:
    print os.path.join(sys.prefix, 'include', py_ver)
    print os.path.join(sys.prefix, 'lib', py_ver, 'config')
print py_ver
""")

        return [python] + self.stdout().strip().split('\n')

    def start(self, *args, **kw):
        """
        Starts SCons in the test environment.

        This method exists to tell Test{Cmd,Common} that we're going to
        use standard input without forcing every .start() call in the
        individual tests to do so explicitly.
        """
        if 'stdin' not in kw:
            kw['stdin'] = True
        sconsflags = initialize_sconsflags(self.ignore_python_version)
        try:
            p = TestCommon.start(self, *args, **kw)
        finally:
            restore_sconsflags(sconsflags)
        return p

    def wait_for(self, fname, timeout=20.0, popen=None):
        """
        Waits for the specified file name to exist.
        """
        waited = 0.0
        while not os.path.exists(fname):
            if timeout and waited >= timeout:
                sys.stderr.write('timed out waiting for %s to exist\n' % fname)
                if popen:
                    popen.stdin.close()
                    popen.stdin = None
                    self.status = 1
                    self.finish(popen)
                stdout = self.stdout()
                if stdout:
                    sys.stdout.write(self.banner('STDOUT ') + '\n')
                    sys.stdout.write(stdout)
                stderr = self.stderr()
                if stderr:
                    sys.stderr.write(self.banner('STDERR ') + '\n')
                    sys.stderr.write(stderr)
                self.fail_test()
            time.sleep(1.0)
            waited = waited + 1.0

    def get_alt_cpp_suffix(self):
        """
        Many CXX tests have this same logic.
        They all needed to determine if the current os supports
        files with .C and .c as different files or not
        in which case they are instructed to use .cpp instead of .C
        """
        if not case_sensitive_suffixes('.c','.C'):
            alt_cpp_suffix = '.cpp'
        else:
            alt_cpp_suffix = '.C'
        return alt_cpp_suffix


class Stat:
    def __init__(self, name, units, expression, convert=None):
        if convert is None:
            convert = lambda x: x
        self.name = name
        self.units = units
        self.expression = re.compile(expression)
        self.convert = convert

StatList = [
    Stat('memory-initial', 'kbytes',
         r'Memory before reading SConscript files:\s+(\d+)',
         convert=lambda s: int(s) // 1024),
    Stat('memory-prebuild', 'kbytes',
         r'Memory before building targets:\s+(\d+)',
         convert=lambda s: int(s) // 1024),
    Stat('memory-final', 'kbytes',
         r'Memory after building targets:\s+(\d+)',
         convert=lambda s: int(s) // 1024),

    Stat('time-sconscript', 'seconds',
         r'Total SConscript file execution time:\s+([\d.]+) seconds'),
    Stat('time-scons', 'seconds',
         r'Total SCons execution time:\s+([\d.]+) seconds'),
    Stat('time-commands', 'seconds',
         r'Total command execution time:\s+([\d.]+) seconds'),
    Stat('time-total', 'seconds',
         r'Total build time:\s+([\d.]+) seconds'),
]


class TimeSCons(TestSCons):
    """Class for timing SCons."""
    def __init__(self, *args, **kw):
        """
        In addition to normal TestSCons.TestSCons intialization,
        this enables verbose mode (which causes the command lines to
        be displayed in the output) and copies the contents of the
        directory containing the executing script to the temporary
        working directory.
        """
        self.variables = kw.get('variables')
        default_calibrate_variables = []
        if self.variables is not None:
            for variable, value in self.variables.items():
                value = os.environ.get(variable, value)
                try:
                    value = int(value)
                except ValueError:
                    try:
                        value = float(value)
                    except ValueError:
                        pass
                    else:
                        default_calibrate_variables.append(variable)
                else:
                    default_calibrate_variables.append(variable)
                self.variables[variable] = value
            del kw['variables']
        calibrate_keyword_arg = kw.get('calibrate')
        if calibrate_keyword_arg is None:
            self.calibrate_variables = default_calibrate_variables
        else:
            self.calibrate_variables = calibrate_keyword_arg
            del kw['calibrate']

        self.calibrate = os.environ.get('TIMESCONS_CALIBRATE', '0') != '0'

        if 'verbose' not in kw and not self.calibrate:
            kw['verbose'] = True

        TestSCons.__init__(self, *args, **kw)

        # TODO(sgk):    better way to get the script dir than sys.argv[0]
        self.test_dir = os.path.dirname(sys.argv[0])
        test_name = os.path.basename(self.test_dir)

        if not os.path.isabs(self.test_dir):
            self.test_dir = os.path.join(self.orig_cwd, self.test_dir)
        self.copy_timing_configuration(self.test_dir, self.workpath())

    def main(self, *args, **kw):
        """
        The main entry point for standard execution of timings.

        This method run SCons three times:

          Once with the --help option, to have it exit after just reading
          the configuration.

          Once as a full build of all targets.

          Once again as a (presumably) null or up-to-date build of
          all targets.

        The elapsed time to execute each build is printed after
        it has finished.
        """
        if 'options' not in kw and self.variables:
            options = []
            for variable, value in self.variables.items():
                options.append('%s=%s' % (variable, value))
            kw['options'] = ' '.join(options)
        if self.calibrate:
            self.calibration(*args, **kw)
        else:
            self.uptime()
            self.startup(*args, **kw)
            self.full(*args, **kw)
            self.null(*args, **kw)

    def trace(self, graph, name, value, units, sort=None):
        fmt = "TRACE: graph=%s name=%s value=%s units=%s"
        line = fmt % (graph, name, value, units)
        if sort is not None:
          line = line + (' sort=%s' % sort)
        line = line + '\n'
        sys.stdout.write(line)
        sys.stdout.flush()

    def report_traces(self, trace, stats):
        self.trace('TimeSCons-elapsed',
                   trace,
                   self.elapsed_time(),
                   "seconds",
                   sort=0)
        for name, args in stats.items():
            self.trace(name, trace, **args)

    def uptime(self):
        try:
            fp = open('/proc/loadavg')
        except EnvironmentError:
            pass
        else:
            avg1, avg5, avg15 = fp.readline().split(" ")[:3]
            fp.close()
            self.trace('load-average',  'average1', avg1, 'processes')
            self.trace('load-average',  'average5', avg5, 'processes')
            self.trace('load-average',  'average15', avg15, 'processes')

    def collect_stats(self, input):
        result = {}
        for stat in StatList:
            m = stat.expression.search(input)
            if m:
                value = stat.convert(m.group(1))
                # The dict keys match the keyword= arguments
                # of the trace() method above so they can be
                # applied directly to that call.
                result[stat.name] = {'value':value, 'units':stat.units}
        return result

    def add_timing_options(self, kw, additional=None):
        """
        Add the necessary timings options to the kw['options'] value.
        """
        options = kw.get('options', '')
        if additional is not None:
            options += additional
        kw['options'] = options + ' --debug=memory,time'

    def startup(self, *args, **kw):
        """
        Runs scons with the --help option.

        This serves as a way to isolate just the amount of startup time
        spent reading up the configuration, since --help exits before any
        "real work" is done.
        """
        self.add_timing_options(kw, ' --help')
        # Ignore the exit status.  If the --help run dies, we just
        # won't report any statistics for it, but we can still execute
        # the full and null builds.
        kw['status'] = None
        self.run(*args, **kw)
        sys.stdout.write(self.stdout())
        stats = self.collect_stats(self.stdout())
        # Delete the time-commands, since no commands are ever
        # executed on the help run and it is (or should be) always 0.0.
        del stats['time-commands']
        self.report_traces('startup', stats)

    def full(self, *args, **kw):
        """
        Runs a full build of SCons.
        """
        self.add_timing_options(kw)
        self.run(*args, **kw)
        sys.stdout.write(self.stdout())
        stats = self.collect_stats(self.stdout())
        self.report_traces('full', stats)
        self.trace('full-memory', 'initial', **stats['memory-initial'])
        self.trace('full-memory', 'prebuild', **stats['memory-prebuild'])
        self.trace('full-memory', 'final', **stats['memory-final'])

    def calibration(self, *args, **kw):
        """
        Runs a full build of SCons, but only reports calibration
        information (the variable(s) that were set for this configuration,
        and the elapsed time to run.
        """
        self.add_timing_options(kw)
        self.run(*args, **kw)
        for variable in self.calibrate_variables:
            value = self.variables[variable]
            sys.stdout.write('VARIABLE: %s=%s\n' % (variable, value))
        sys.stdout.write('ELAPSED: %s\n' % self.elapsed_time())

    def null(self, *args, **kw):
        """
        Runs an up-to-date null build of SCons.
        """
        # TODO(sgk):  allow the caller to specify the target (argument)
        # that must be up-to-date.
        self.add_timing_options(kw)
        self.up_to_date(arguments='.', **kw)
        sys.stdout.write(self.stdout())
        stats = self.collect_stats(self.stdout())
        # time-commands should always be 0.0 on a null build, because
        # no commands should be executed.  Remove it from the stats
        # so we don't trace it, but only if it *is* 0 so that we'll
        # get some indication if a supposedly-null build actually does
        # build something.
        if float(stats['time-commands']['value']) == 0.0:
            del stats['time-commands']
        self.report_traces('null', stats)
        self.trace('null-memory', 'initial', **stats['memory-initial'])
        self.trace('null-memory', 'prebuild', **stats['memory-prebuild'])
        self.trace('null-memory', 'final', **stats['memory-final'])

    def elapsed_time(self):
        """
        Returns the elapsed time of the most recent command execution.
        """
        return self.endTime - self.startTime

    def run(self, *args, **kw):
        """
        Runs a single build command, capturing output in the specified file.

        Because this class is about timing SCons, we record the start
        and end times of the elapsed execution, and also add the
        --debug=memory and --debug=time options to have SCons report
        its own memory and timing statistics.
        """
        self.startTime = time.time()
        try:
            result = TestSCons.run(self, *args, **kw)
        finally:
            self.endTime = time.time()
        return result

    def copy_timing_configuration(self, source_dir, dest_dir):
        """
        Copies the timing configuration from the specified source_dir (the
        directory in which the controlling script lives) to the specified
        dest_dir (a temporary working directory).

        This ignores all files and directories that begin with the string
        'TimeSCons-', and all '.svn' subdirectories.
        """
        for root, dirs, files in os.walk(source_dir):
            if '.svn' in dirs:
                dirs.remove('.svn')
            dirs = [ d for d in dirs if not d.startswith('TimeSCons-') ]
            files = [ f for f in files if not f.startswith('TimeSCons-') ]
            for dirname in dirs:
                source = os.path.join(root, dirname)
                destination = source.replace(source_dir, dest_dir)
                os.mkdir(destination)
                if sys.platform != 'win32':
                    shutil.copystat(source, destination)
            for filename in files:
                source = os.path.join(root, filename)
                destination = source.replace(source_dir, dest_dir)
                shutil.copy2(source, destination)


# In some environments, $AR will generate a warning message to stderr
# if the library doesn't previously exist and is being created.  One
# way to fix this is to tell AR to be quiet (sometimes the 'c' flag),
# but this is difficult to do in a platform-/implementation-specific
# method.  Instead, we will use the following as a stderr match for
# tests that use AR so that we will view zero or more "ar: creating
# <file>" messages to be successful executions of the test (see
# test/AR.py for sample usage).

noisy_ar=r'(ar: creating( archive)? \S+\n?)*'

# Local Variables:
# tab-width:4
# indent-tabs-mode:nil
# End:
# vim: set expandtab tabstop=4 shiftwidth=4: