sconstruct

# A part of NonVisual Desktop Access (NVDA)
# Copyright (C) 2010-2023 NV Access Limited, James Teh, Michael Curran, Peter Vágner, Joseph Lee,
# Reef Turner, Babbage B.V., Leonard de Ruijter, Łukasz Golonka, Accessolutions, Julien Cochuyt,
# Cyrille Bougot
# This file may be used under the terms of the GNU General Public License, version 2 or later.
# For more details see: https://www.gnu.org/licenses/gpl-2.0.html

import multiprocessing
import os
import platform
import sys


# Ensure we are inside the Python virtual environment.
nvdaVenv = os.getenv("NVDA_VENV")
virtualEnv = os.getenv("VIRTUAL_ENV")
if not virtualEnv or not os.path.isdir(virtualEnv): 
	print(
		"Error: SCons cannot detect the NVDA build system Python virtual environment.\n"
		"SCons must be executed using scons.bat in the root of this repository."
	)
	sys.exit(1)
if nvdaVenv != virtualEnv:
	print("Warning: SCons launched within a custom Python virtual environment.")

# Variables for storing required version of Python, and the version which is used to run this script.
requiredPythonMajor = "3"
requiredPythonMinor = "11"
requiredPythonArchitecture = "32bit"
installedPythonMajor = str(sys.version_info.major)
installedPythonMinor = str(sys.version_info.minor)
installedPythonArchitecture = platform.architecture()[0]
# Ensure that we are running with required version of Python, otherwise inform the user and exit.
if (
	installedPythonArchitecture != requiredPythonArchitecture
	or installedPythonMajor != requiredPythonMajor
	or installedPythonMinor != requiredPythonMinor
):
	unsupportedPythonMsg = (
		("This script is started with Python %s.%s %s, however to build NVDA you have to use Python %s.%s %s.\n"
		"Please install the needed version of Python and launch SCons again, or if you have multiple "
		"versions of Python installed start this script with required version explicitly.")
	)
	raise RuntimeError(unsupportedPythonMsg %(
		installedPythonMajor,
		installedPythonMinor,
		installedPythonArchitecture,
		requiredPythonMajor,
		requiredPythonMinor,
		requiredPythonArchitecture
	)
	)
sourceEnvPath = os.path.abspath(os.path.join(Dir('.').srcnode().path, "source"))
sys.path.append(sourceEnvPath)
import sourceEnv
sys.path.remove(sourceEnvPath)
import time
import importlib.util
import winreg

def recursiveCopy(env,targetDir,sourceDir):
	targets=[]
	for topDir,subDirs,files in os.walk(sourceDir.abspath):
		relTopDir=os.path.relpath(topDir,sourceDir.abspath)
		for f in files:
			fNode=targetDir.Dir(relTopDir).File(f)
			env.Command(fNode,Dir(topDir).File(f),Copy('$TARGET','$SOURCE'))
			targets.append(fNode)
		if len(files)==0:
			dNode=targetDir.Dir(relTopDir)
			env.Command(dNode,Dir(topDir),Mkdir('$TARGET'))
			targets.append(dNode)
	return targets

# Import NVDA's versionInfo module.
import gettext
gettext.install("nvda")
sys.path.append("source")
import versionInfo
del sys.path[-1]

makensis = os.path.abspath(os.path.join("include", "nsis", "NSIS", "makensis.exe"))

# Get the path to xgettext.
XGETTEXT = os.path.abspath(os.path.join("miscDeps", "tools", "xgettext.exe"))

import txt2tags  # noqa: F401, import required here to build docs

vars = Variables()
vars.Add("version", "The version of this build", versionInfo.version)
vars.Add("version_build", "A unique number for this build.", "0")
vars.Add(BoolVariable("release", "Whether this is a release version", False))
vars.Add("publisher", "The publisher of this build", versionInfo.publisher)
vars.Add("updateVersionType", "The version type for which to check for updates", versionInfo.updateVersionType or "")
vars.Add(PathVariable("certFile", "The certificate file with which to sign executables", "",
	lambda key, val, env: not val or PathVariable.PathIsFile(key, val, env)))
vars.Add("certPassword", "The password for the private key in the signing certificate", "")
vars.Add("certTimestampServer", "The URL of the timestamping server to use to timestamp authenticode signatures", "")
vars.Add(PathVariable("outputDir", "The directory where the final built archives and such will be placed", "output",PathVariable.PathIsDirCreate))
vars.Add(ListVariable("nvdaHelperDebugFlags", "a list of debugging features you require", 'none', ["debugCRT","RTC","analyze"]))
vars.Add(EnumVariable('nvdaHelperLogLevel','The level of logging you wish to see, lower is more verbose','15',allowed_values=[str(x) for x in range(60)]))

#Base environment for this and sub sconscripts
env = Environment(variables=vars,HOST_ARCH='x86',tools=[
	"textfile",
	"gettextTool",
	"t2t",
	"md2html",
	"doxygen",
	"recursiveInstall"
])

# speed up subsequent runs by checking timestamps of targets and dependencies, and only using md5 if timestamps differ.
env.Decider('MD5-timestamp')

# Warn to run the build on multiple threads so it runs faster
numJobs = env.GetOption('num_jobs')
numCores = multiprocessing.cpu_count()
if numJobs < numCores:
	print(
		f"Warning: Building with {numJobs} concurrent job{'s' if numJobs != 1 else ''} "
		f"while {numCores} CPU threads are available. "
		f"Running SCONS with the parameter '-j{numCores}' may lead to a faster build."
	)
else:
	print(f"Building with {numJobs} concurrent jobs")

#Make our recursiveCopy function available to any script using this environment
env.AddMethod(recursiveCopy)

#Check for any unknown variables
unknown=vars.UnknownVariables().keys()
if len(unknown)>0:
	print("Unknown commandline variables: %s"%unknown)
	Exit(1)

#Ensure that any Python subprocesses (such as for py2exe) can find our Python directory in miscDeps
env['ENV']['PYTHONPATH']=";".join(sourceEnv.PYTHON_DIRS)

env["copyright"]=versionInfo.copyright
env['version_year']=versionInfo.version_year
env['version_major']=versionInfo.version_major
env['version_minor']=versionInfo.version_minor
version = env["version"]
version_build = env["version_build"]
release = env["release"]
publisher = env["publisher"]
certFile = env["certFile"]
certPassword = env["certPassword"]
certTimestampServer = env["certTimestampServer"]
userDocsDir=Dir('user_docs')
sourceDir = env.Dir("source")
Export('sourceDir')
clientDir=Dir('extras/controllerClient')
Export('clientDir')
sourceLibDir=sourceDir.Dir('lib')
Export('sourceLibDir')
sourceTypelibDir=sourceDir.Dir('typelibs')
Export('sourceTypelibDir')
sourceLibDir64=sourceDir.Dir('lib64')
Export('sourceLibDir64')
sourceLibDirArm64=sourceDir.Dir('libArm64')
Export('sourceLibDirArm64')
buildDir = Dir("build")
outFilePrefix = "nvda{type}_{version}".format(type="" if release else "_snapshot", version=version)
Export('outFilePrefix')
outputDir=Dir(env['outputDir'])
Export('outputDir')

# An action to sign an executable with certFile.
# we encrypt with SHA256 as this is the minimum required by the Windows Store for appx packages 
signExecCmd = ["signtool", "sign", "/fd", "SHA256", "/f", certFile]
if certPassword:
	signExecCmd.extend(("/p", certPassword))
if certTimestampServer:
	signExecCmd.extend(("/tr", certTimestampServer, "/td", "SHA256"))
def signExec(target,source,env):
	print([str(x) for x in target])
	#sys.exit(1)
	# #3795: signtool can quite commonly fail with timestamping, so allow it to try up to 3 times with a 1 second delay between each try. 
	res=0
	for count in range(3):
		res=env.Execute([signExecCmd+[target[0].abspath]])
		if not res:
			return 0 # success
		time.sleep(1)
	return res # failed
#Export via scons environment so other libraries can be signed
env['signExec']=signExec

#architecture-specific environments
archTools=['default','midl','msrpc']
env32=env.Clone(TARGET_ARCH='x86',tools=archTools)
env64=env.Clone(TARGET_ARCH='x86_64',tools=archTools)
envArm64=env.Clone(TARGET_ARCH='arm64',tools=archTools)
# Hack around odd bug where some tool [after] msvc states that static and shared objects are different
env32['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1
env64['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1
envArm64['STATIC_AND_SHARED_OBJECTS_ARE_THE_SAME'] = 1

env=env32

projectRCSubstDict={
	'%version_year%':env['version_year'],
	'%version_major%':env['version_major'],
	'%version_minor%':env['version_minor'],
	'%version_build%':env['version_build'],
	'%copyright%':env['copyright'],
	'%publisher%':env['publisher'],
	'%version%':env['version'],
	'%productName%':"%s (%s)"%(versionInfo.name,versionInfo.longName),
}
resFile=env.RES(target='build/nvda.res',
	source=env.Substfile(target='build/nvda.rc', source='nvdaHelper/nvda.rc.subst', SUBST_DICT=projectRCSubstDict))
env32['projectResFile'] = resFile
env64['projectResFile'] = resFile
envArm64['projectResFile'] = resFile

#Fill sourceDir with anything provided for it by miscDeps
env.recursiveCopy(sourceDir,Dir('miscdeps/source'))
# Copy in some other dependencies.
jabDll = "windowsaccessbridge-32.dll"
Command(sourceLibDir.File(jabDll),
	env.Dir("#include/javaAccessBridge32").File(jabDll),
	Copy("$TARGET", "$SOURCE"))

env.SConscript('source/comInterfaces_sconscript',exports=['env'])

#Process nvdaHelper scons files
env32.SConscript('nvdaHelper/archBuild_sconscript',exports={'env':env32,'clientInstallDir':clientDir.Dir('x86'),'libInstallDir':sourceLibDir},variant_dir='build/x86')
env64.SConscript('nvdaHelper/archBuild_sconscript',exports={'env':env64,'clientInstallDir':clientDir.Dir('x64'),'libInstallDir':sourceLibDir64},variant_dir='build/x86_64')
envArm64.SConscript('nvdaHelper/archBuild_sconscript',exports={'env':envArm64,'clientInstallDir':clientDir.Dir('arm64'),'libInstallDir':sourceLibDirArm64},variant_dir='build/arm64')

#Allow all NVDA's gettext po files to be compiled in source/locale
for po in env.Glob(sourceDir.path+'/locale/*/lc_messages/*.po'):
	env.gettextMoFile(po)

userGuideConf = os.path.join(userDocsDir.path, 'userGuide.t2tconf')
globalConf = os.path.join(userDocsDir.path, 'global.t2tconf')
changesConf = os.path.join(userDocsDir.path, 'changes.t2tconf')
styles = os.path.join(userDocsDir.path, 'styles.css')

#Allow all t2t files to be converted to html in user_docs
#As we use scons Glob this will also include the keyCommands.t2t files
for t2tFile in env.Glob(os.path.join(userDocsDir.path,'*','*.t2t')):
	mdFile = env.txt2tags(t2tFile)
	#txt2tags can not be run in parallel so make sure scons knows this
	env.SideEffect('_txt2tags', mdFile)
	env.Depends(
		mdFile,
		[
			userGuideConf,
			globalConf,
			changesConf,
		]
	)
	htmlFile = env.md2html(t2tFile.abspath.replace(".t2t", ".md"))
	styleInstallPath = os.path.dirname(t2tFile.abspath)
	installedStyle = env.Install(styleInstallPath, styles)
	env.Depends(
		htmlFile,
		[
			styles,
			installedStyle,
		]
	)
	env.Depends(htmlFile, mdFile)

# Create key commands files
for userGuideFile in env.Glob(os.path.join(userDocsDir.path, '*', 'userGuide.md')):
	keyCommandsHtmlFile = env.md2html(userGuideFile.abspath.replace("userGuide.md", "keyCommands.html"), userGuideFile)
	env.Depends(keyCommandsHtmlFile, userGuideFile)

# Build unicode CLDR dictionaries
env.SConscript('cldrDict_sconscript',exports=['env', 'sourceDir'])

# A builder to generate an NVDA distribution.
def NVDADistGenerator(target, source, env, for_signature):
	buildVersionFn = os.path.join(str(source[0]), "_buildVersion.py")
	# Make the NVDA build use the specified version.
	# We don't do this using normal scons mechanisms because we want it to be cleaned up immediately after this builder
	# and py2exe will cause bytecode files to be created for it which scons doesn't know about.
	updateVersionType = env["updateVersionType"] or None
	# Any '\n' characters written are translated to the system default line separator, os.linesep.
	action = [lambda target, source, env: open(buildVersionFn, "w", encoding="utf-8").write(
		'version = {version!r}\n'
		'publisher = {publisher!r}\n'
		'updateVersionType = {updateVersionType!r}\n'
		'version_build = {version_build!r}\n'
		.format(version=version, publisher=publisher, updateVersionType=updateVersionType,version_build=version_build)
	)
	# In Python 3 write returns the number of characters written,
	# which scons treats as an error code.	
	and None]

	buildCmd = ["cd", source[0].path, "&&", sys.executable]
	if release:
		buildCmd.append("-O")
	# Issue errors about str(bytes_instance), str(bytearray_instance)
	buildCmd.append("-bb")
	buildCmd.append("setup.py")
	if env.get("uiAccess"):
		buildCmd.append("--enable-uiAccess")

	action.append(buildCmd)

	# #10031: Apps written in Python 3 require Universal CRT to be installed. We cannot assume users have it on their systems.
	# Therefore , copy required libraries from Windows 10 SDK.
	try:
		with winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, r'SOFTWARE\Microsoft\Microsoft SDKs\Windows\v10.0', 0,winreg.KEY_READ|winreg.KEY_WOW64_32KEY) as SDKKey:
			sdk_installationFolder = winreg.QueryValueEx(SDKKey, 'InstallationFolder')[0]
			sdk_productVersion = winreg.QueryValueEx(SDKKey, 'ProductVersion')[0]
	except WindowsError:
		raise RuntimeError("Windows 10 SDK not found")
	# The Universal CRT should be in an SDK version-specific directory
	# But usually has a '.0' appended after the productVersion found in the registry. 
	# E.g. 10.0.1941 might e actually 10.0.1941.0.
	# Thus try both.
	CRTDir = os.path.join(sdk_installationFolder, "Redist", sdk_productVersion+".0", "ucrt", "DLLs", "x86")
	if not os.path.isdir(CRTDir):
		CRTDir = os.path.join(sdk_installationFolder, "Redist", sdk_productVersion, "ucrt", "DLLs", "x86")
		if not os.path.isdir(CRTDir):
			raise RuntimeError(f"Could not locate CRT dlls in SDK at {CRTDir}")
	with os.scandir(CRTDir) as dir:
		for file in dir:
			if file.name.endswith(".dll") and file.is_file():
				action.append(Copy(target[0], file.path))

	if certFile:
		for prog in "nvda_noUIAccess.exe", "nvda_uiAccess.exe", "nvda_slave.exe":
			action.append(lambda target,source,env, progByVal=prog: signExec([target[0].File(progByVal)],source,env))

	action.extend((
		Delete(buildVersionFn),
		Delete(importlib.util.cache_from_source(buildVersionFn))
	))

	return action
env["BUILDERS"]["NVDADist"] = Builder(generator=NVDADistGenerator, target_factory=Dir)

# A builder to generate a zip archive.
# We roll our own instead of using env.Zip because we want to create some archives
# relative to a specified directory.
def ZipArchiveAction(target, source, env):
	relativeTo = env.get("relativeTo", None)
	if relativeTo:
		relativeTo = relativeTo.path
		def getArcName(origName):
			arcName = os.path.relpath(origName, relativeTo)
			if arcName.startswith(".."):
				arcName = arcName.replace(".." + os.path.sep, "")
			return "" if arcName == "." else arcName
	else:
		getArcName = lambda origName: "" if origName == "." else origName

	# Nasty hack to make zipfile use best compression, since it isn't configurable.
	# Tried setting memlevel to 9 as well, but it made compression slightly worse.
	import zlib
	origZDefComp = zlib.Z_DEFAULT_COMPRESSION
	zlib.Z_DEFAULT_COMPRESSION = zlib.Z_BEST_COMPRESSION

	import zipfile
	zf = None
	try:
		zf = zipfile.ZipFile(target[0].path, "w", zipfile.ZIP_DEFLATED)
		for s in source:
			if os.path.isdir(s.path):
				for path, dirs, files in os.walk(s.path):
					arcPath = getArcName(path)
					if arcPath:
						zf.write(path, arcPath)
					for f in files:
						zf.write(os.path.join(path, f), os.path.join(arcPath, f))
			else:
				zf.write(s.path, getArcName(s.path))

	finally:
		if zf:
			zf.close()
		zlib.Z_DEFAULT_COMPRESSION = origZDefComp

env["BUILDERS"]["ZipArchive"] = Builder(action=ZipArchiveAction)

uninstFile=File("dist/uninstall.exe")
uninstGen = env.Command(File("uninstaller/uninstGen.exe"), "uninstaller/uninst.nsi",
	[[makensis, "/V2",
	"/DVERSION=$version", '/DPUBLISHER="$publisher"','/DCOPYRIGHT="$copyright"','/DVERSION_YEAR="$version_year"','/DVERSION_MAJOR="$version_major"','/DVERSION_MINOR="$version_minor"','/DVERSION_BUILD="$version_build"',
	"/DUNINSTEXE=%s"%uninstFile.abspath,
	"/DINSTEXE=${TARGET.abspath}",
	"$SOURCE"]])
uninstaller=env.Command(uninstFile,uninstGen,[uninstGen])
if certFile:
	env.AddPostAction(uninstaller, [signExec])

dist = env.NVDADist("dist", [sourceDir,userDocsDir], uiAccess=bool(certFile))
env.Depends(dist,uninstaller)
# dist will always be considered obsolete
AlwaysBuild(dist)
# Dir node targets don't get cleaned, so cleaning of the dist nodes has to be explicitly specified.
env.Clean(dist, dist)
# Clean the intermediate build directory.
env.Clean([dist], buildDir)

launcher = env.Command(outputDir.File("%s.exe" % outFilePrefix), ["launcher/nvdaLauncher.nsi", dist],
	[[makensis, "/V2",
	"/DVERSION=$version", '/DPUBLISHER="$publisher"','/DCOPYRIGHT="$copyright"','/DVERSION_YEAR="$version_year"','/DVERSION_MAJOR="$version_major"','/DVERSION_MINOR="$version_minor"','/DVERSION_BUILD="$version_build"',
	"/DNVDADistDir=${SOURCES[1].abspath}", "/DLAUNCHEREXE=${TARGET.abspath}",
	"$SOURCE"]])
if certFile:
	env.AddPostAction(launcher, [signExec])
env.Alias("launcher", launcher)

clientArchive = env.ZipArchive(outputDir.File("%s_controllerClient.zip" % outFilePrefix), clientDir, relativeTo=clientDir)
env.Alias("client", clientArchive)

outputStylesFile=env.Command(outputDir.File("styles.css"),userDocsDir.File('styles.css'),Copy('$TARGET','$SOURCE'))
changesFile=env.Command(outputDir.File("%s_changes.html" % outFilePrefix),userDocsDir.File('en/changes.html'),Copy('$TARGET','$SOURCE'))
changesMDFile = env.Command(
	outputDir.File("changes.md"),
	userDocsDir.File('en/changes.md'),
	Copy('$TARGET','$SOURCE')
)
env.Depends(changesFile, changesMDFile)
env.Depends(changesFile, outputStylesFile)
env.Alias('changes',changesFile)

userGuideFile=env.Command(outputDir.File("userGuide.html"),userDocsDir.File('en/userGuide.html'),Copy('$TARGET','$SOURCE'))
userGuideMDFile = env.Command(
	outputDir.File("userGuide.md"),
	userDocsDir.File('en/userGuide.md'),
	Copy('$TARGET', '$SOURCE')
)
env.Depends(userGuideFile, userGuideMDFile)
env.Depends(userGuideFile, outputStylesFile)
env.Alias('userGuide', userGuideFile)

keyCommandsFile = env.Command(
	outputDir.File("keyCommands.html"),
	userDocsDir.File('en/keyCommands.html'),
	Copy('$TARGET', '$SOURCE')
)
env.Depends(keyCommandsFile, outputStylesFile)
env.Depends(keyCommandsFile, userGuideFile)
env.Alias('keyCommands', keyCommandsFile)

def makePotSourceFileList(target, sourceFiles, env):
	potSourceFiles = [
		os.path.relpath(str(f), str(sourceDir)) for f in sourceFiles
	]
	with open(target.abspath, "w") as fileList:
		fileList.writelines([f + '\n' for f in potSourceFiles])


def makePot(target, source, env):
	potSourceFileList = outputDir.File("potSourceFileList.txt")
	makePotSourceFileList(potSourceFileList, source, env)
	# Generate the pot.
	if env.Execute([
		[
			"cd", sourceDir, "&&",
			XGETTEXT,
			"-o", target[0].abspath,
			"--package-name", versionInfo.name, "--package-version", version,
			"--foreign-user",
			"--add-comments=Translators:",
			"--keyword=pgettext:1c,2",
			"--keyword=npgettext:1c,2,3",
			"--from-code", "utf-8",
			# Needed because xgettext doesn't recognise the .pyw extension.
			"--language=python",
			# Too many files to list on commandline, use a file list instead.
			f"--files-from={potSourceFileList.abspath}",
		]
	]) != 0:
		raise RuntimeError("xgettext failed")

	# Tweak the headers.
	potFn = str(target[0])
	tmpFn = "%s.tmp" % potFn
	with open(potFn, "rt", encoding="utf-8") as inp, open(tmpFn, "wt", encoding="utf-8") as out:
		for lineNum, line in enumerate(inp):
			if lineNum == 1:
				line = "# %s\n" % versionInfo.copyright
			elif lineNum == 2:
				# Delete line.
				continue
			elif lineNum == 15:
				line = line.replace("CHARSET", "UTF-8")
			out.write(line)
	os.remove(potFn)
	os.rename(tmpFn, potFn)


env.SConscript("projectDocs/dev/developerGuide/sconscript", exports=["env", "outputDir", "sourceDir"])


def getSubDirs(path):
	for root, dirNames, fileNames in os.walk(path):
		yield root


# The Glob() SCons function doesnt have the ability to go recursive. Instead
# walk the dirs and match patterns.
potSourceFiles = [
	# Don't use sourceDir as the source, as this depends on comInterfaces and nvdaHelper.
	# We only depend on the Python files.
	f for recurseDirs in getSubDirs(sourceDir.path)
	if not (
		# Exclude comInterfaces, since these don't contain translatable strings
		# and they cause unknown encoding warnings.
		recurseDirs.startswith(r"source\comInterfaces")
		# Exclude userConfig folder which does not contain NVDA code but may contain gettext call without
		# translator comments in add-ons or scratchpad, triggering false positive for checkpot script.
		or recurseDirs.startswith(r"source\userConfig")
	)	
	for pattern in ("*.py", "*.pyw")
	for f in env.Glob(
		os.path.join(recurseDirs, pattern),
	)
]

pot = env.Command(
	outputDir.File("nvda.pot"),
	potSourceFiles,
	makePot
)

env.Alias("pot", pot)

symbolsList=[]
symbolsList.extend(env.Glob(os.path.join(sourceLibDir.path,'*.pdb')))
symbolsList.extend(env.Glob(os.path.join(sourceLibDir64.path,'*.pdb')))
symbolsArchive = env.ZipArchive(outputDir.File("%s_debugSymbols.zip" % outFilePrefix), symbolsList)
env.Alias("symbolsArchive", symbolsArchive)

appx_storeSubmission=env.SConscript("appx/sconscript",exports={'env':env,'isStoreSubmission':True},variant_dir='build\\appx_storeSubmission')
installed_appx_storeSubmission=env.Install('output',appx_storeSubmission)
appx_sideLoadable=env.SConscript("appx/sconscript",exports={'env':env,'isStoreSubmission':False},variant_dir='build\\appx_sideLoadable')
installed_appx_sideLoadable=env.Install('output',appx_sideLoadable)
env.Alias('appx',[installed_appx_storeSubmission,installed_appx_sideLoadable])

env.Default(dist)

env.SConscript("tests/sconscript", exports=["env", "sourceDir", "pot"])


# Generate a list of Python modules from compiled '.pyc' files in library.zip
env.Tool("listModules")
source = env.Dir(os.path.join(os.getcwd(), "dist"))
# Putting the target in the output dir automatically causes AppVeyor to package it as an artefact
target = env.File(os.path.join(outputDir.abspath, "library_modules.txt"))
env.Alias("moduleList", env.GenerateModuleList(target, source))