blob: 9df2cd9e1136bc9fedbf3c57f449854346d45d5e [file] [log] [blame]
#!/usr/bin/env python
# The way you use this is you create a script that takes in as its first
# argument a count. The script passes into LLVM the count via a command
# line flag that disables a pass after LLVM has run after the pass has
# run for count number of times. Then the script invokes a test of some
# sort and indicates whether LLVM successfully compiled the test via the
# scripts exit status. Then you invoke bisect as follows:
# bisect --start=<start_num> --end=<end_num> ./ "%(count)s"
# And bisect will continually call ./ with various counts using
# the exit status to determine success and failure.
from __future__ import print_function
import os
import sys
import argparse
import subprocess
parser = argparse.ArgumentParser()
parser.add_argument('--start', type=int, default=0)
parser.add_argument('--end', type=int, default=(1 << 32))
parser.add_argument('command', nargs='+')
args = parser.parse_args()
start = args.start
end = args.end
print("Bisect Starting!")
print("Start: %d" % start)
print("End: %d" % end)
last = None
while start != end and start != end-1:
count = start + (end - start)//2
print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
cmd = [x % {'count':count} for x in args.command]
result =
if result == 0:
print(" PASSES! Setting start to count")
start = count
print(" FAILS! Setting end to count")
end = count
print("Last good count: %d" % start)