summaryrefslogtreecommitdiffstats
path: root/bitbake/lib/bb/utils.py
blob: ba50801ae9ec375d9046fe2af034f9a13a0d1ff0 (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
# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
"""
BitBake Utility Functions
"""

# Copyright (C) 2004 Michael Lauer
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

import re, fcntl, os, string, stat, shutil, time
import sys
import errno
import logging
import bb
import bb.msg
from commands import getstatusoutput
from contextlib import contextmanager

logger = logging.getLogger("BitBake.Util")

# Version comparison
separators = ".-"

# Context used in better_exec, eval
_context = {
    "os": os,
    "bb": bb,
    "time": time,
}

def explode_version(s):
    r = []
    alpha_regexp = re.compile('^([a-zA-Z]+)(.*)$')
    numeric_regexp = re.compile('^(\d+)(.*)$')
    while (s != ''):
        if s[0] in string.digits:
            m = numeric_regexp.match(s)
            r.append(int(m.group(1)))
            s = m.group(2)
            continue
        if s[0] in string.letters:
            m = alpha_regexp.match(s)
            r.append(m.group(1))
            s = m.group(2)
            continue
        r.append(s[0])
        s = s[1:]
    return r

def vercmp_part(a, b):
    va = explode_version(a)
    vb = explode_version(b)
    sa = False
    sb = False
    while True:
        if va == []:
            ca = None
        else:
            ca = va.pop(0)
        if vb == []:
            cb = None
        else:
            cb = vb.pop(0)
        if ca == None and cb == None:
            return 0

        if isinstance(ca, basestring):
            sa = ca in separators
        if isinstance(cb, basestring):
            sb = cb in separators
        if sa and not sb:
            return -1
        if not sa and sb:
            return 1

        if ca > cb:
            return 1
        if ca < cb:
            return -1

def vercmp(ta, tb):
    (ea, va, ra) = ta
    (eb, vb, rb) = tb

    r = int(ea or 0) - int(eb or 0)
    if (r == 0):
        r = vercmp_part(va, vb)
    if (r == 0):
        r = vercmp_part(ra, rb)
    return r

_package_weights_ = {"pre":-2, "p":0, "alpha":-4, "beta":-3, "rc":-1}    # dicts are unordered
_package_ends_ = ["pre", "p", "alpha", "beta", "rc", "cvs", "bk", "HEAD" ]            # so we need ordered list

def relparse(myver):
    """Parses the last elements of a version number into a triplet, that can
    later be compared.
    """

    number = 0
    p1 = 0
    p2 = 0
    mynewver = myver.split('_')
    if len(mynewver) == 2:
        # an _package_weights_
        number = float(mynewver[0])
        match = 0
        for x in _package_ends_:
            elen = len(x)
            if mynewver[1][:elen] == x:
                match = 1
                p1 = _package_weights_[x]
                try:
                    p2 = float(mynewver[1][elen:])
                except:
                    p2 = 0
                break
        if not match:
            # normal number or number with letter at end
            divider = len(myver)-1
            if myver[divider:] not in "1234567890":
                # letter at end
                p1 = ord(myver[divider:])
                number = float(myver[0:divider])
            else:
                number = float(myver)
    else:
        # normal number or number with letter at end
        divider = len(myver)-1
        if myver[divider:] not in "1234567890":
            #letter at end
            p1 = ord(myver[divider:])
            number = float(myver[0:divider])
        else:
            number = float(myver)
    return [number, p1, p2]

__vercmp_cache__ = {}

def vercmp_string(val1, val2):
    """This takes two version strings and returns an integer to tell you whether
    the versions are the same, val1>val2 or val2>val1.
    """

    # quick short-circuit
    if val1 == val2:
        return 0
    valkey = val1 + " " + val2

    # cache lookup
    try:
        return __vercmp_cache__[valkey]
        try:
            return - __vercmp_cache__[val2 + " " + val1]
        except KeyError:
            pass
    except KeyError:
        pass

    # consider 1_p2 vc 1.1
    # after expansion will become (1_p2,0) vc (1,1)
    # then 1_p2 is compared with 1 before 0 is compared with 1
    # to solve the bug we need to convert it to (1,0_p2)
    # by splitting _prepart part and adding it back _after_expansion

    val1_prepart = val2_prepart = ''
    if val1.count('_'):
        val1, val1_prepart = val1.split('_', 1)
    if val2.count('_'):
        val2, val2_prepart = val2.split('_', 1)

    # replace '-' by '.'
    # FIXME: Is it needed? can val1/2 contain '-'?

    val1 = val1.split("-")
    if len(val1) == 2:
        val1[0] = val1[0] + "." + val1[1]
    val2 = val2.split("-")
    if len(val2) == 2:
        val2[0] = val2[0] + "." + val2[1]

    val1 = val1[0].split('.')
    val2 = val2[0].split('.')

    # add back decimal point so that .03 does not become "3" !
    for x in xrange(1, len(val1)):
        if val1[x][0] == '0' :
            val1[x] = '.' + val1[x]
    for x in xrange(1, len(val2)):
        if val2[x][0] == '0' :
            val2[x] = '.' + val2[x]

    # extend varion numbers
    if len(val2) < len(val1):
        val2.extend(["0"]*(len(val1)-len(val2)))
    elif len(val1) < len(val2):
        val1.extend(["0"]*(len(val2)-len(val1)))

    # add back _prepart tails
    if val1_prepart:
        val1[-1] += '_' + val1_prepart
    if val2_prepart:
        val2[-1] += '_' + val2_prepart
    # The above code will extend version numbers out so they
    # have the same number of digits.
    for x in xrange(0, len(val1)):
        cmp1 = relparse(val1[x])
        cmp2 = relparse(val2[x])
        for y in xrange(0, 3):
            myret = cmp1[y] - cmp2[y]
            if myret != 0:
                __vercmp_cache__[valkey] = myret
                return myret
    __vercmp_cache__[valkey] = 0
    return 0

def explode_deps(s):
    """
    Take an RDEPENDS style string of format:
    "DEPEND1 (optional version) DEPEND2 (optional version) ..."
    and return a list of dependencies.
    Version information is ignored.
    """
    r = []
    l = s.split()
    flag = False
    for i in l:
        if i[0] == '(':
            flag = True
            #j = []
        if not flag:
            r.append(i)
        #else:
        #    j.append(i)
        if flag and i.endswith(')'):
            flag = False
            # Ignore version
            #r[-1] += ' ' + ' '.join(j)
    return r

def explode_dep_versions(s):
    """
    Take an RDEPENDS style string of format:
    "DEPEND1 (optional version) DEPEND2 (optional version) ..."
    and return a dictionary of dependencies and versions.
    """
    r = {}
    l = s.replace(",", "").split()
    lastdep = None
    lastver = ""
    inversion = False
    for i in l:
        if i[0] == '(':
            inversion = True
            lastver = i[1:] or ""
            #j = []
        elif inversion and i.endswith(')'):
            inversion = False
            lastver = lastver + " " + (i[:-1] or "")
            r[lastdep] = lastver
        elif not inversion:
            r[i] = None
            lastdep = i
            lastver = ""
        elif inversion:
            lastver = lastver + " " + i

    return r

def join_deps(deps):
    """
    Take the result from explode_dep_versions and generate a dependency string
    """
    result = []
    for dep in deps:
        if deps[dep]:
            result.append(dep + " (" + deps[dep] + ")")
        else:
            result.append(dep)
    return ", ".join(result)

def extend_deps(dest, src):
    """
    Extend the results from explode_dep_versions by appending all of the items
    in the second list, avoiding duplicates.
    """
    for dep in src:
        if dep not in dest:
            dest[dep] = src[dep]
        elif dest[dep] != src[dep]:
            dest[dep] = src[dep]

def _print_trace(body, line):
    """
    Print the Environment of a Text Body
    """
    # print the environment of the method
    min_line = max(1, line-4)
    max_line = min(line + 4, len(body))
    for i in xrange(min_line, max_line + 1):
        if line == i:
            logger.error(" *** %.4d:%s" % (i, body[i-1]) )
        else:
            logger.error("     %.4d:%s" % (i, body[i-1]) )


def better_compile(text, file, realfile, mode = "exec"):
    """
    A better compile method. This method
    will print  the offending lines.
    """
    try:
        return compile(text, file, mode)
    except Exception as e:
        # split the text into lines again
        body = text.split('\n')
        logger.error("Error in compiling python function in: %s" % (realfile))
        logger.error(str(e))
        if e.lineno:
            logger.error("The lines leading to this error were:")
            logger.error("\t%d:%s:'%s'" % (e.lineno, e.__class__.__name__, body[e.lineno-1]))
            _print_trace(body, e.lineno)
        else:
            logger.error("The function causing this error was:")
            for line in body:
                logger.error(line)
        raise

def better_exec(code, context, text, realfile = "<code>"):
    """
    Similiar to better_compile, better_exec will
    print the lines that are responsible for the
    error.
    """
    import bb.parse
    if not hasattr(code, "co_filename"):
        code = better_compile(code, realfile, realfile)
    try:
        exec(code, _context, context)
    except Exception:
        (t, value, tb) = sys.exc_info()

        if t in [bb.parse.SkipPackage, bb.build.FuncFailed]:
            raise

        logger.exception("Error executing python function in '%s'", code.co_filename)

        # print the Header of the Error Message
        logger.error("There was an error when executing a python function in: %s" % code.co_filename)
        logger.error("Exception:%s Message:%s" % (t, value))

        # Strip 'us' from the stack (better_exec call)
        tb = tb.tb_next

        import traceback
        textarray = text.split('\n')
        linefailed = traceback.tb_lineno(tb)

        tbextract = traceback.extract_tb(tb)
        tbformat = "\n".join(traceback.format_list(tbextract))
        logger.error("The stack trace of python calls that resulted in thie exception/failure was:")
        for line in tbformat.split('\n'):
            logger.error(line)

        logger.error("The code that was being executed was:")
        _print_trace(textarray, linefailed)
        logger.error("(file: '%s', lineno: %s, function: %s)" % (tbextract[0][0], tbextract[0][1], tbextract[0][2]))

        # See if this is a function we constructed and has calls back into other functions in 
        # "text". If so, try and improve the context of the error by diving down the trace
        level = 0
        nexttb = tb.tb_next
        while nexttb is not None:
            if tbextract[level][0] == tbextract[level+1][0] and tbextract[level+1][2] == tbextract[level][0]:
                _print_trace(textarray, tbextract[level+1][1])
                logger.error("(file: '%s', lineno: %s, function: %s)" % (tbextract[level+1][0], tbextract[level+1][1], tbextract[level+1][2]))
            else:
                 break
            nexttb = tb.tb_next
            level = level + 1

        raise

def simple_exec(code, context):
    exec(code, _context, context)

def better_eval(source, locals):
    return eval(source, _context, locals)

@contextmanager
def fileslocked(files):
    locks = []
    if files:
        for lockfile in files:
            locks.append(bb.utils.lockfile(lock))

    yield

    for lock in locks:
        bb.utils.unlockfile(lock)

def lockfile(name):
    """
    Use the file fn as a lock file, return when the lock has been acquired.
    Returns a variable to pass to unlockfile().
    """
    path = os.path.dirname(name)
    if not os.path.isdir(path):
        logger.error("Lockfile path '%s' does not exist", path)
        sys.exit(1)

    if not os.access(path, os.W_OK):
        logger.error("Error, lockfile path is not writable!: %s" % path)
        sys.exit(1)

    while True:
        # If we leave the lockfiles lying around there is no problem
        # but we should clean up after ourselves. This gives potential
        # for races though. To work around this, when we acquire the lock
        # we check the file we locked was still the lock file on disk.
        # by comparing inode numbers. If they don't match or the lockfile
        # no longer exists, we start again.

        # This implementation is unfair since the last person to request the
        # lock is the most likely to win it.

        try:
            lf = open(name, "a + ")
            fcntl.flock(lf.fileno(), fcntl.LOCK_EX)
            statinfo = os.fstat(lf.fileno())
            if os.path.exists(lf.name):
                statinfo2 = os.stat(lf.name)
                if statinfo.st_ino == statinfo2.st_ino:
                    return lf
            # File no longer exists or changed, retry
            lf.close
        except Exception as e:
            continue

def unlockfile(lf):
    """
    Unlock a file locked using lockfile()
    """
    os.unlink(lf.name)
    fcntl.flock(lf.fileno(), fcntl.LOCK_UN)
    lf.close

def md5_file(filename):
    """
    Return the hex string representation of the MD5 checksum of filename.
    """
    try:
        import hashlib
        m = hashlib.md5()
    except ImportError:
        import md5
        m = md5.new()

    for line in open(filename):
        m.update(line)
    return m.hexdigest()

def sha256_file(filename):
    """
    Return the hex string representation of the 256-bit SHA checksum of
    filename.  On Python 2.4 this will return None, so callers will need to
    handle that by either skipping SHA checks, or running a standalone sha256sum
    binary.
    """
    try:
        import hashlib
    except ImportError:
        return None

    s = hashlib.sha256()
    for line in open(filename):
        s.update(line)
    return s.hexdigest()

# Variables which are preserved from the original environment *and* exported
# into our worker context
def preserved_envvars_export_list():
    return [
        'BB_TASKHASH',
        'HOME',
        'LOGNAME',
        'PATH',
        'PWD',
        'SHELL',
        'TERM',
        'USER',
        'USERNAME',
    ]

# Variables which are preserved from the original environment *and* exported
# into our worker context for interactive tasks (e.g. requiring X)
def preserved_envvars_export_interactive_list():
    return [
        'COLORTERM',
        'DBUS_SESSION_BUS_ADDRESS',
        'DESKTOP_SESSION',
        'DESKTOP_STARTUP_ID',
        'DISPLAY',
        'GNOME_KEYRING_PID',
        'GNOME_KEYRING_SOCKET',
        'GPG_AGENT_INFO',
        'GTK_RC_FILES',
        'SESSION_MANAGER',
        'SSH_AUTH_SOCK',
        'XAUTHORITY',
        'XDG_DATA_DIRS',
        'XDG_SESSION_COOKIE',
    ]

# Variables which are preserved from the original environment into the datastore
def preserved_envvars_list():
    v = [
        'BBPATH',
        'BB_PRESERVE_ENV',
        'BB_ENV_WHITELIST',
        'BB_ENV_EXTRAWHITE',
        'LANG',
        '_',
    ]
    return v + preserved_envvars_export_list() + preserved_envvars_export_interactive_list()

def filter_environment(good_vars):
    """
    Create a pristine environment for bitbake. This will remove variables that
    are not known and may influence the build in a negative way.
    """

    removed_vars = []
    for key in os.environ.keys():
        if key in good_vars:
            continue

        removed_vars.append(key)
        os.unsetenv(key)
        del os.environ[key]

    if len(removed_vars):
        logger.debug(1, "Removed the following variables from the environment: %s", ", ".join(removed_vars))

    return removed_vars

def create_intereactive_env(d):
    for k in preserved_envvars_export_interactive_list():
        os.setenv(k, bb.data.getVar(k, d, True))

def clean_environment():
    """
    Clean up any spurious environment variables. This will remove any
    variables the user hasn't chose to preserve.
    """
    if 'BB_PRESERVE_ENV' not in os.environ:
        if 'BB_ENV_WHITELIST' in os.environ:
            good_vars = os.environ['BB_ENV_WHITELIST'].split()
        else:
            good_vars = preserved_envvars_list()
        if 'BB_ENV_EXTRAWHITE' in os.environ:
            good_vars.extend(os.environ['BB_ENV_EXTRAWHITE'].split())
        filter_environment(good_vars)

def empty_environment():
    """
    Remove all variables from the environment.
    """
    for s in os.environ.keys():
        os.unsetenv(s)
        del os.environ[s]

def build_environment(d):
    """
    Build an environment from all exported variables.
    """
    import bb.data
    for var in bb.data.keys(d):
        export = bb.data.getVarFlag(var, "export", d)
        if export:
            os.environ[var] = bb.data.getVar(var, d, True) or ""

def remove(path, recurse=False):
    """Equivalent to rm -f or rm -rf"""
    import os, errno, shutil
    try:
        os.unlink(path)
    except OSError, exc:
        if recurse and exc.errno == errno.EISDIR:
            shutil.rmtree(path)
        elif exc.errno != errno.ENOENT:
            raise

def prunedir(topdir):
    # Delete everything reachable from the directory named in 'topdir'.
    # CAUTION:  This is dangerous!
    for root, dirs, files in os.walk(topdir, topdown = False):
        for name in files:
            os.remove(os.path.join(root, name))
        for name in dirs:
            if os.path.islink(os.path.join(root, name)):
                os.remove(os.path.join(root, name))
            else:
                os.rmdir(os.path.join(root, name))
    os.rmdir(topdir)

#
# Could also use return re.compile("(%s)" % "|".join(map(re.escape, suffixes))).sub(lambda mo: "", var)
# but thats possibly insane and suffixes is probably going to be small
#
def prune_suffix(var, suffixes, d):
    # See if var ends with any of the suffixes listed and
    # remove it if found
    for suffix in suffixes:
        if var.endswith(suffix):
            return var.replace(suffix, "")
    return var

def mkdirhier(dir):
    """Create a directory like 'mkdir -p', but does not complain if
    directory already exists like os.makedirs
    """

    logger.debug(3, "mkdirhier(%s)", dir)
    try:
        os.makedirs(dir)
        logger.debug(2, "created " + dir)
    except OSError as e:
        if e.errno != errno.EEXIST:
            raise e

def movefile(src, dest, newmtime = None, sstat = None):
    """Moves a file from src to dest, preserving all permissions and
    attributes; mtime will be preserved even when moving across
    filesystems.  Returns true on success and false on failure. Move is
    atomic.
    """

    #print "movefile(" + src + "," + dest + "," + str(newmtime) + "," + str(sstat) + ")"
    try:
        if not sstat:
            sstat = os.lstat(src)
    except Exception as e:
        print("movefile: Stating source file failed...", e)
        return None

    destexists = 1
    try:
        dstat = os.lstat(dest)
    except:
        dstat = os.lstat(os.path.dirname(dest))
        destexists = 0

    if destexists:
        if stat.S_ISLNK(dstat[stat.ST_MODE]):
            try:
                os.unlink(dest)
                destexists = 0
            except Exception as e:
                pass

    if stat.S_ISLNK(sstat[stat.ST_MODE]):
        try:
            target = os.readlink(src)
            if destexists and not stat.S_ISDIR(dstat[stat.ST_MODE]):
                os.unlink(dest)
            os.symlink(target, dest)
            #os.lchown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
            os.unlink(src)
            return os.lstat(dest)
        except Exception as e:
            print("movefile: failed to properly create symlink:", dest, "->", target, e)
            return None

    renamefailed = 1
    if sstat[stat.ST_DEV] == dstat[stat.ST_DEV]:
        try:
            os.rename(src, dest)
            renamefailed = 0
        except Exception as e:
            if e[0] != errno.EXDEV:
                # Some random error.
                print("movefile: Failed to move", src, "to", dest, e)
                return None
            # Invalid cross-device-link 'bind' mounted or actually Cross-Device

    if renamefailed:
        didcopy = 0
        if stat.S_ISREG(sstat[stat.ST_MODE]):
            try: # For safety copy then move it over.
                shutil.copyfile(src, dest + "#new")
                os.rename(dest + "#new", dest)
                didcopy = 1
            except Exception as e:
                print('movefile: copy', src, '->', dest, 'failed.', e)
                return None
        else:
            #we don't yet handle special, so we need to fall back to /bin/mv
            a = getstatusoutput("/bin/mv -f " + "'" + src + "' '" + dest + "'")
            if a[0] != 0:
                print("movefile: Failed to move special file:" + src + "' to '" + dest + "'", a)
                return None # failure
        try:
            if didcopy:
                os.lchown(dest, sstat[stat.ST_UID], sstat[stat.ST_GID])
                os.chmod(dest, stat.S_IMODE(sstat[stat.ST_MODE])) # Sticky is reset on chown
                os.unlink(src)
        except Exception as e:
            print("movefile: Failed to chown/chmod/unlink", dest, e)
            return None

    if newmtime:
        os.utime(dest, (newmtime, newmtime))
    else:
        os.utime(dest, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))
        newmtime = sstat[stat.ST_MTIME]
    return newmtime

def copyfile(src, dest, newmtime = None, sstat = None):
    """
    Copies a file from src to dest, preserving all permissions and
    attributes; mtime will be preserved even when moving across
    filesystems.  Returns true on success and false on failure.
    """
    #print "copyfile(" + src + "," + dest + "," + str(newmtime) + "," + str(sstat) + ")"
    try:
        if not sstat:
            sstat = os.lstat(src)
    except Exception as e:
        print("copyfile: Stating source file failed...", e)
        return False

    destexists = 1
    try:
        dstat = os.lstat(dest)
    except:
        dstat = os.lstat(os.path.dirname(dest))
        destexists = 0

    if destexists:
        if stat.S_ISLNK(dstat[stat.ST_MODE]):
            try:
                os.unlink(dest)
                destexists = 0
            except Exception as e:
                pass

    if stat.S_ISLNK(sstat[stat.ST_MODE]):
        try:
            target = os.readlink(src)
            if destexists and not stat.S_ISDIR(dstat[stat.ST_MODE]):
                os.unlink(dest)
            os.symlink(target, dest)
            #os.lchown(dest,sstat[stat.ST_UID],sstat[stat.ST_GID])
            return os.lstat(dest)
        except Exception as e:
            print("copyfile: failed to properly create symlink:", dest, "->", target, e)
            return False

    if stat.S_ISREG(sstat[stat.ST_MODE]):
        os.chmod(src, stat.S_IRUSR) # Make sure we can read it
        try: # For safety copy then move it over.
            shutil.copyfile(src, dest + "#new")
            os.rename(dest + "#new", dest)
        except Exception as e:
            print('copyfile: copy', src, '->', dest, 'failed.', e)
            return False
        finally:
            os.chmod(src, sstat[stat.ST_MODE])
            os.utime(src, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))

    else:
        #we don't yet handle special, so we need to fall back to /bin/mv
        a = getstatusoutput("/bin/cp -f " + "'" + src + "' '" + dest + "'")
        if a[0] != 0:
            print("copyfile: Failed to copy special file:" + src + "' to '" + dest + "'", a)
            return False # failure
    try:
        os.lchown(dest, sstat[stat.ST_UID], sstat[stat.ST_GID])
        os.chmod(dest, stat.S_IMODE(sstat[stat.ST_MODE])) # Sticky is reset on chown
    except Exception as e:
        print("copyfile: Failed to chown/chmod/unlink", dest, e)
        return False

    if newmtime:
        os.utime(dest, (newmtime, newmtime))
    else:
        os.utime(dest, (sstat[stat.ST_ATIME], sstat[stat.ST_MTIME]))
        newmtime = sstat[stat.ST_MTIME]
    return newmtime

def which(path, item, direction = 0):
    """
    Locate a file in a PATH
    """

    paths = (path or "").split(':')
    if direction != 0:
        paths.reverse()

    for p in paths:
        next = os.path.join(p, item)
        if os.path.exists(next):
            return next

    return ""

def init_logger(logger, verbose, debug, debug_domains):
    """
    Set verbosity and debug levels in the logger
    """

    if debug:
        bb.msg.set_debug_level(debug)
    elif verbose:
        bb.msg.set_verbose(True)
    else:
        bb.msg.set_debug_level(0)

    if debug_domains:
        bb.msg.set_debug_domains(debug_domains)