Update xperf_to_collapsedstacks.py to Python 3

xperf_to_collapsedstacks.py was written for Python 2 and was never
updated until now. This fixes its print statements and also puts its
string constants into standard single-quote form. With the python 3
fixes it now works under Python 2 or 3.

While the code still works under Python 2 that may not be maintained
forever.

bin/xperf_to_collapsedstacks.py

@@ -30,6 +30,9 @@
 column labels and the rest is the fields from the profile - process, threadID, and '/' separated
 stack.
 """
+
+from __future__ import print_function
+
 import sys
 import os
 import time
@@ -38,8 +41,8 @@
 
 # Our usage of subprocess seems to require Python 2.7+
 if sys.version_info.major == 2 and sys.version_info.minor < 7:
-  print("Your python version is too old - 2.7 or higher required.")
-  print("Python version is %s" % sys.version)
+  print('Your python version is too old - 2.7 or higher required.')
+  print('Python version is %s' % sys.version)
   sys.exit(0)
 
 parser = argparse.ArgumentParser(description='Process xperf ETL file and generate flamegraph(s).')
@@ -49,7 +52,7 @@
 parser.add_argument('-b', '--begin', help='Time range. Begin from the specified value. In seconds.', type=float)
 parser.add_argument('-e', '--end', help='Time range. End at the specified value. In seconds.', type=float)
 parser.add_argument('-o', '--output', help='Path to directory where output will written into. Default is system TEMP directory', type=str)
-parser.set_defaults(output=os.environ["temp"])
+parser.set_defaults(output=os.environ['temp'])
 parser.add_argument('-n', '--numshow', help='Number of top processes to generate flame graph for. Default is 1', type=int)
 parser.set_defaults(numshow=1)
 parser.add_argument('-d', '--dontopen', help='Do not open the generated SVG file automatically. Default is open', action='store_true')
@@ -65,38 +68,38 @@
 
 scriptPath = os.path.abspath(sys.argv[0])
 scriptDir = os.path.split(scriptPath)[0]
-flameGraphPath = os.path.join(scriptDir, "flamegraph.pl")
+flameGraphPath = os.path.join(scriptDir, 'flamegraph.pl')
 if not os.path.exists(flameGraphPath):
-	print "Couldn't find \"%s\". Download it from https://github.com/brendangregg/FlameGraph/blob/master/flamegraph.pl" % flameGraphPath
+	print('Couldn\'t find "%s". Download it from https://github.com/brendangregg/FlameGraph/blob/master/flamegraph.pl' % flameGraphPath)
 	sys.exit(0)
 
-profilePath = os.path.join(scriptDir, "ExportCPUUsageSampled.wpaProfile")
+profilePath = os.path.join(scriptDir, 'ExportCPUUsageSampled.wpaProfile')
 if not os.path.exists(profilePath):
-	print "Couldn't find \"%s\". This should be part of the UIforETW repo and releases" % profilePath
+	print('Couldn\'t find "%s". This should be part of the UIforETW repo and releases' % profilePath)
 	sys.exit(0)
 
-#if not os.environ.has_key("_NT_SYMBOL_PATH"):
-#	print "_NT_SYMBOL_PATH is not set. Exiting."
+#if not '_NT_SYMBOL_PATH' in os.environ:
+#	print('_NT_SYMBOL_PATH is not set. Exiting.')
 #	sys.exit(0)
 
-if os.environ.has_key("ProgramFiles(x86)"):
-	progFilesx86 = os.environ["ProgramFiles(x86)"]
+if 'ProgramFiles(x86)' in os.environ:
+	progFilesx86 = os.environ['ProgramFiles(x86)']
 else:
-	progFilesx86 = os.environ["ProgramFiles"]
-wpaExporterPath = os.path.join(progFilesx86, r"Windows Kits\10\Windows Performance Toolkit\wpaexporter.EXE")
+	progFilesx86 = os.environ['ProgramFiles']
+wpaExporterPath = os.path.join(progFilesx86, r'Windows Kits\10\Windows Performance Toolkit\wpaexporter.EXE')
 if not os.path.exists(wpaExporterPath):
-	print "Couldn't find \"%s\". Make sure WPT 10 is installed." % wpaExporterPath
+	print('Couldn\'t find "%s". Make sure WPT 10 is installed.' % wpaExporterPath)
 	sys.exit(0)
 
 if args.begin and args.end:
 	wpaCommand = r'"%s" "%s" -range %ss %ss -profile "%s" -symbols' % (wpaExporterPath, args.etlFilename, args.begin, args.end, profilePath)
 else:
 	wpaCommand = r'"%s" "%s" -profile "%s" -symbols' % (wpaExporterPath, args.etlFilename, profilePath)
 
-print "> %s" % wpaCommand
-start = time.clock()
-print subprocess.check_output(wpaCommand, stderr=subprocess.STDOUT)
-print "Elapsed time for wpaexporter: %1.3f s" % (time.clock() - start)
+print('> %s' % wpaCommand)
+start = time.time()
+print(subprocess.check_output(wpaCommand, stderr=subprocess.STDOUT))
+print('Elapsed time for wpaexporter: %1.3f s' % (time.time() - start))
 
 
 # This dictionary of dictionaries accumulates sample data. The first key is
@@ -109,37 +112,37 @@
 
 # Process all of the lines in the output of wpaexporter, skipping the first line
 # which is just the column names.
-csvName = "CPU_Usage_(Sampled)_Randomascii_Export.csv"
+csvName = 'CPU_Usage_(Sampled)_Randomascii_Export.csv'
 for line in open(csvName).readlines()[1:]:
 	line = line.strip()
-	firstCommaPos = line.find(",")
+	firstCommaPos = line.find(',')
 	process = line[:firstCommaPos]
 	if processList and process.split(' ')[0].lower() not in processList:
 		continue
-	secondCommaPos = line.find(",", firstCommaPos + 1)
+	secondCommaPos = line.find(',', firstCommaPos + 1)
 	threadID = line[firstCommaPos + 1 : secondCommaPos]
 	stackSummary = line[secondCommaPos + 1:]
-	if stackSummary == "n/a":
+	if stackSummary == 'n/a':
 		continue
 	# Since we are using semicolon separators we can't have semicolons
 	# in the function names.
-	stackSummary = stackSummary.replace(";", ":")
+	stackSummary = stackSummary.replace(';', ':')
 	# Spaces seem like a bad idea also.
-	stackSummary = stackSummary.replace(" ", "_")
+	stackSummary = stackSummary.replace(' ', '_')
 	# Having single-quote characters in the call stacks gives flamegraph.pl heartburn.
 	# Replace them with back ticks.
-	stackSummary = stackSummary.replace("'", "`")
+	stackSummary = stackSummary.replace('\'', '`')
 	# Double-quote characters also cause problems. Remove them.
-	stackSummary = stackSummary.replace('"', "")
+	stackSummary = stackSummary.replace('"', '')
 	# Remove <PDB_not_found> labels
-	stackSummary = stackSummary.replace("<PDB_not_found>", "Unknown")
+	stackSummary = stackSummary.replace('<PDB_not_found>', 'Unknown')
 	# Convert the wpaexporter stack separators to flamegraph stack separators
-	stackSummary = stackSummary.replace("/", ";")
-	#stackSummary = "A;B;C"
+	stackSummary = stackSummary.replace('/', ';')
+	#stackSummary = 'A;B;C'
 
-	processAndThread = "%s_%s" % (process.replace(" ", "_"), threadID)
-	processAndThread = processAndThread.replace("(", "")
-	processAndThread = processAndThread.replace(")", "")
+	processAndThread = '%s_%s' % (process.replace(' ', '_'), threadID)
+	processAndThread = processAndThread.replace('(', '')
+	processAndThread = processAndThread.replace(')', '')
 	# Add the record to the nested dictionary, and increment the count
 	# if it already exists.
 	if not processAndThread in samples:
@@ -162,40 +165,43 @@
 sortedThreads.sort() # Put the threads in order by number of samples
 sortedThreads.reverse() # Put the thread with the most samples first
 
-print "Found %d samples from %d threads." % (totalSamples, len(samples))
+print('Found %d samples from %d threads.' % (totalSamples, len(samples)))
 
 if len(processList)>0:
 	numToShow = len(sortedThreads)
 
 count = 0
 for numSamples, processAndThread in sortedThreads[:numToShow]:
 	threadSamples = samples[processAndThread]
-	outputName = os.path.join(args.output, "collapsed_stacks_%d.txt" % count)
+	outputName = os.path.join(args.output, 'collapsed_stacks_%d.txt' % count)
 	count += 1
-	print "Writing %d samples to temporary file %s" % (numSamples, outputName)
+	print('Writing %d samples to temporary file %s' % (numSamples, outputName))
 	sortedStacks = []
 	for stack in threadSamples:
-		sortedStacks.append("%s %d\n" % (stack, threadSamples[stack]))
+		sortedStacks.append('%s %d\n' % (stack, threadSamples[stack]))
 	sortedStacks.sort()
 	# Some versions of perl (the version that ships with Chromium's depot_tools
 	# for one) can't handle reading files with CRLF line endings, so write the
-	# file as binary to avoid line-ending translation.
-	out = open(outputName, "wb")
+	# file with Linux-style line endings. This won't work with Python 2.
+	try:
+		out = open(outputName, 'w', newline='\n')
+	except TypeError:
+		out = open(outputName, 'wb')
 	for stack in sortedStacks:
 		out.write(stack)
 	# Force the file closed so that the results will be available when we the
 	# perl script is run.
 	out.close()
 
-	destPath = os.path.join(args.output, "%s.svg" % processAndThread)
-	title = "CPU Usage flame graph of %s" % processAndThread
+	destPath = os.path.join(args.output, '%s.svg' % processAndThread)
+	title = 'CPU Usage flame graph of %s' % processAndThread
 	perlCommand = 'perl "%s" --title="%s" "%s"' % (flameGraphPath, title, outputName)
-	print "> %s" % perlCommand
+	print('> %s' % perlCommand)
 	svgOutput = subprocess.check_output(perlCommand)
 	if len(svgOutput) > 100:
-		open(destPath, "wt").write(svgOutput)
+		open(destPath, 'wt').write(svgOutput.decode())
 		if not args.dontopen:
 			os.popen(destPath)
-		print 'Results are in "%s" - they should be auto-opened in the default SVG viewer.' % destPath
+		print('Results are in "%s" - they should be auto-opened in the default SVG viewer.' % destPath)
 	else:
-		print "Result size is %d bytes - is perl in your path?" % len(svgOutput)
+		print('Result size is %d bytes - is perl in your path?' % len(svgOutput))