[utils] Fix incompatibility of bisect[-skip-count] with Python 3

[miyuki]

Summary

This change replaces the print statements with print function calls
and also replaces the '/' operator (which is integer division in Py2,
but becomes floating point division in Py3) with the '//' operator
which has the same semantics in Py2 and Py3.

[greened]

What happens when this is run with python 2 in the path? Should this explicitly run via python3?

[miyuki]

In D68138#1686487, @greened wrote:

What happens when this is run with python 2 in the path? Should this explicitly run via python3?

No, the scripts are now compatible with both python 2 and 3, I've checked that.

[greened]

LGTM.

[greened]

Should this use from __future__ import print_function to avoid someone accidentially printing arguments as a tuple?

[greened]

The more I think about this, the more I do think this should use from __future__ import print_function.

[miyuki]

Added from __future__ import print_function

[greened]

LGTM, thanks!

llvm/trunk/utils/bisect

 #!/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> ./script.sh "%(count)s"
 #
 # And bisect will continually call ./script.sh 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
+    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]
-    print cmd
+    print(cmd)
     result = subprocess.call(cmd)
     if result == 0:
         print("    PASSES! Setting start to count")
         start = count
     else:
         print("    FAILS! Setting end to count")
         end = count
 
 print("Last good count: %d" % start)

llvm/trunk/utils/bisect-skip-count

 # opt -debug-counter=my-counter-skip=${skip},my-counter-count=${count}
 # ... Test output of opt and exit zero for pass, non-zero for fail
 #
 # Examine bisect.out to look for "Last good skip" and "Last good
 # count" to find the values of the counter that produce a passing
 # result.  Incrementing the last good count by one or decrementing the
 # last good skip by one should produce a failure.
 #
+from __future__ import print_function
 import os
 import sys
 import argparse
 # This is for timeout support. Use the recommended way of import.
 # We do timeouts because when doing, execution testing, we have a habit
 # of finding variants that infinite loop
 if os.name == 'posix' and sys.version_info[0] < 3:
   import subprocess32 as subprocess

 end = args.skipend
 
 print("Bisect of Skip starting!")
 print("Start: %d" % start)
 print("End: %d" % end)
 
 last = None
 while start != end and start != end-1:
-    count = start + (end - start)/2
+    count = start + (end - start)//2
     print("Visiting Skip: %d with (Start, End) = (%d,%d)" % (count, start, end))
     cmd = [x % {'skip':count, 'count':-1} for x in args.command]
-    print cmd
+    print(cmd)
     try:
         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
         if result == 0:
            print("    PASSES! Setting end to count")
            end = count
         else:
            print("    FAILS! Setting start to count")
            start = count
     except:
         print(" TIMEOUT, setting end to count")
         end = count
 firstcount = start
 print("Last good skip: %d" % start)
 start = args.countstart
 end = args.countend
 print("Bisect of Count starting!")
 print("Start: %d" % start)
 print("End: %d" % end)
 while start != end and start != end-1:
-    count = start + (end - start)/2
+    count = start + (end - start)//2
     print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
     cmd = [x % {'count':count, 'skip':firstcount } for x in args.command]
-    print cmd
+    print(cmd)
     try:
         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
         if result == 0:
            print("    PASSES! Setting start to count")
            start = count
         else:
            print("    FAILS! Setting end to count")
            end = count
     except:
         print(" TIMEOUT, setting start to count")
         start = count
 
 print("Last good count: %d" % start)