1#!/usr/bin/env python
2# This script is used to bisect skip and count arguments for --debug-counter.
3# It is similar to bisect, except it understands how to increase skip and decrease count
4#
5# Typical usage:
6#
7# bisect-skip-count bisect-command.sh "%(skip)d" "%(count)d" 2>&1 | tee bisect.out
8#
9# bisect-command.sh is something like this:
10# #! /bin/bash
11#
12# skip=$1
13# count=$2
14#
15# opt -debug-counter=my-counter-skip=${skip},my-counter-count=${count}
16# ... Test output of opt and exit zero for pass, non-zero for fail
17#
18# Examine bisect.out to look for "Last good skip" and "Last good
19# count" to find the values of the counter that produce a passing
20# result.  Incrementing the last good count by one or decrementing the
21# last good skip by one should produce a failure.
22#
23import os
24import sys
25import argparse
26# This is for timeout support. Use the recommended way of import.
27# We do timeouts because when doing, execution testing, we have a habit
28# of finding variants that infinite loop
29if os.name == 'posix' and sys.version_info[0] < 3:
30  import subprocess32 as subprocess
31else:
32  import subprocess
33parser = argparse.ArgumentParser()
34
35parser.add_argument('--skipstart', type=int, default=0)
36parser.add_argument('--skipend', type=int, default=(1 << 32))
37parser.add_argument('--countstart', type=int, default=0)
38parser.add_argument('--countend', type=int, default=(1 << 32))
39parser.add_argument('--timeout', type=int, default=None)
40# Use shell support if you need to use complex shell expressions in your command
41parser.add_argument('--shell', type=bool, default=False)
42parser.add_argument('command', nargs='+')
43
44args = parser.parse_args()
45
46start = args.skipstart
47end = args.skipend
48
49print("Bisect of Skip starting!")
50print("Start: %d" % start)
51print("End: %d" % end)
52
53last = None
54while start != end and start != end-1:
55    count = start + (end - start)/2
56    print("Visiting Skip: %d with (Start, End) = (%d,%d)" % (count, start, end))
57    cmd = [x % {'skip':count, 'count':-1} for x in args.command]
58    print cmd
59    try:
60        result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
61        if result == 0:
62           print("    PASSES! Setting end to count")
63           end = count
64        else:
65           print("    FAILS! Setting start to count")
66           start = count
67    except:
68        print(" TIMEOUT, setting end to count")
69        end = count
70firstcount = start
71print("Last good skip: %d" % start)
72start = args.countstart
73end = args.countend
74print("Bisect of Count starting!")
75print("Start: %d" % start)
76print("End: %d" % end)
77while start != end and start != end-1:
78    count = start + (end - start)/2
79    print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
80    cmd = [x % {'count':count, 'skip':firstcount } for x in args.command]
81    print cmd
82    try:
83        result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
84        if result == 0:
85           print("    PASSES! Setting start to count")
86           start = count
87        else:
88           print("    FAILS! Setting end to count")
89           end = count
90    except:
91        print(" TIMEOUT, setting start to count")
92        start = count
93
94print("Last good count: %d" % start)
95