llvm-project

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#!/usr/bin/env python3
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# This script is used to bisect skip and count arguments for --debug-counter.
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# It is similar to bisect, except it understands how to increase skip and decrease count
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#
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# Typical usage:
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#
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# bisect-skip-count bisect-command.sh "%(skip)d" "%(count)d" 2>&1 | tee bisect.out
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#
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# bisect-command.sh is something like this:
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# #! /bin/bash
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#
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# skip=$1
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# count=$2
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#
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# opt -debug-counter=my-counter-skip=${skip},my-counter-count=${count}
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# ... Test output of opt and exit zero for pass, non-zero for fail
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#
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# Examine bisect.out to look for "Last good skip" and "Last good
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# count" to find the values of the counter that produce a passing
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# result.  Incrementing the last good count by one or decrementing the
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# last good skip by one should produce a failure.
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#
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from __future__ import print_function
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import os
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import sys
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import argparse
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# This is for timeout support. Use the recommended way of import.
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# We do timeouts because when doing, execution testing, we have a habit
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# of finding variants that infinite loop
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if os.name == 'posix' and sys.version_info[0] < 3:
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  import subprocess32 as subprocess
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else:
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  import subprocess
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parser = argparse.ArgumentParser()
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parser.add_argument('--skipstart', type=int, default=0)
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parser.add_argument('--skipend', type=int, default=(1 << 32))
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parser.add_argument('--countstart', type=int, default=0)
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parser.add_argument('--countend', type=int, default=(1 << 32))
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parser.add_argument('--timeout', type=int, default=None)
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# Use shell support if you need to use complex shell expressions in your command
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parser.add_argument('--shell', type=bool, default=False)
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parser.add_argument('command', nargs='+')
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args = parser.parse_args()
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start = args.skipstart
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end = args.skipend
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print("Bisect of Skip starting!")
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print("Start: %d" % start)
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print("End: %d" % end)
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last = None
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while start != end and start != end-1:
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    count = start + (end - start)//2
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    print("Visiting Skip: %d with (Start, End) = (%d,%d)" % (count, start, end))
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    cmd = [x % {'skip':count, 'count':-1} for x in args.command]
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    print(cmd)
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    try:
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        result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
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        if result == 0:
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           print("    PASSES! Setting end to count")
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           end = count
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        else:
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           print("    FAILS! Setting start to count")
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           start = count
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    except:
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        print(" TIMEOUT, setting end to count")
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        end = count
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firstcount = start
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print("Last good skip: %d" % start)
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start = args.countstart
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end = args.countend
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print("Bisect of Count starting!")
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print("Start: %d" % start)
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print("End: %d" % end)
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while start != end and start != end-1:
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    count = start + (end - start)//2
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    print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
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    cmd = [x % {'count':count, 'skip':firstcount } for x in args.command]
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    print(cmd)
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    try:
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        result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
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        if result == 0:
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           print("    PASSES! Setting start to count")
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           start = count
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        else:
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           print("    FAILS! Setting end to count")
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           end = count
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    except:
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        print(" TIMEOUT, setting start to count")
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        start = count
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print("Last good count: %d" % start)
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