unity-merge-mercurial.py

import csv, os, subprocess

def Main():
	unityPid = GetUnityProcessID()
	if unityPid:
		print('Error: Unity is running (process ID {})'.format(unityPid))
		return 1

	# Make sure we have all heads that we need to merge locally:
	RunCommand(['hg', 'pull', '-b', '.'])

	# Check if the working directory is clean:
	revision = GetOutput(['hg', 'id', '-i']).rstrip()
	if revision.endswith('+'):
		print('Error: Working directory is not clean, please commit your changes before merging')
		return 1

	# First use mercurial's merging:
	RunCommand(['hg', 'merge', '--tool', 'internal:merge'], showOutput = False)
	
	# Then get a list of files which remain to resolve:
	output = GetOutput(['hg', 'resolve', '-l'])
	resolveList = output.splitlines()
	
	for entry in resolveList:
		type = entry[0]
		pathname = entry[2:]
		if type == 'U':
			ResolveFile(pathname)

	RunCommand(['hg', 'commit', '-m', 'Scripted merge of Unity project'])
	
	return 0

def ResolveFile(pathname):
	name = os.path.split(pathname)[1]
	lower = pathname.lower()
	
	outputs = ('_data/managed/assembly-csharp.dll',
		'_data/maindata',
		'_data/output_log.txt',
		'_data/resources.assets',
		'_data/sharedassets0.assets')
	
	takeLocal = False
	if lower.endswith(outputs):
		takeLocal = True
	
	if takeLocal:
		ResolveLocal(pathname)

	if lower.endswith('.unity'):
		ResolveYAML(pathname)

def ResolveLocal(pathname):
	RunCommand(['hg', 'resolve', '--tool', 'internal:local', pathname])
	os.remove(pathname + '.orig')

def ResolveYAML(pathname):
	# First get access to the base, other and local YAML files:
	RunCommand(['hg', 'resolve', '--tool', 'internal:dump', pathname])
	
	# UnityYAMLMerge doesn't like merging files if they don't have the extension '.unity' so we need to rename them:
	baseName   = pathname + '.base'
	otherName  = pathname + '.other'
	localName  = pathname + '.local'
	baseUnity  = baseName + '.unity'
	otherUnity = otherName + '.unity'
	localUnity = localName + '.unity'
	os.rename(baseName,  baseUnity)
	os.rename(otherName, otherUnity)
	os.rename(localName, localUnity)

	# Run the semantic merge:
	scriptDir = os.path.dirname(os.path.realpath(__file__))
	yamlMerge = os.path.join(scriptDir, 'UnityYAMLMerge.exe')
	RunCommand([yamlMerge, 'merge', '-r', baseUnity, otherUnity, localUnity, pathname])
	
	# Mark the output file as resolved:
	RunCommand(['hg', 'resolve', '-m', pathname])
	
	# Delete the temporary files:
	os.remove(baseUnity)
	os.remove(otherUnity)
	os.remove(localUnity)
	os.remove(pathname + '.orig')

# Wrapper to run a command using subprocess:
def RunCommand(args, showOutput = True):
	print(subprocess.list2cmdline(args))
	
	if showOutput:
		process = subprocess.Popen(args)
	else:
		process = subprocess.Popen(args, stdout = open(os.devnull, 'w'), stderr=subprocess.STDOUT)
	
	retcode = process.wait()
	return retcode

# Run a command using subprocess and get the output
def GetOutput(args):
	stdout, stderr = subprocess.Popen(args, stdout = subprocess.PIPE).communicate()
	return stdout

def GetUnityProcessID():	
	output = GetOutput(['tasklist.exe', '/fo', 'csv', '/nh'])
	lines = output.splitlines()
	for line in csv.reader(lines):
		if line[0].lower() == 'unity.exe':
			return line[1]
	return None
		
if __name__ == '__main__':
	exit(Main())