diff --git a/waflib/extras/clang_cl.py b/waflib/extras/clang_cl.py
index 7e196c8b..adc9658e 100644
--- a/waflib/extras/clang_cl.py
+++ b/waflib/extras/clang_cl.py
@@ -16,9 +16,9 @@ Usage:
 Or:
 	$ LLVM_PATH=C:\\Program Files\\LLVM\\bin waf configure
 Or:
-	def configure(conf):
-		conf.env.LLVM_PATH = 'C:\\Program Files\\LLVM\\bin'
-		conf.load('clang_cl')
+	def configure(self):
+		self.env.LLVM_PATH = 'C:\\Program Files\\LLVM\\bin'
+		self.load('clang_cl')
 """
 
 import sys, os
@@ -31,86 +31,90 @@ def options(opt):
 	msvc.options(opt)
 
 @conf
-def find_clang_cl(conf):
-	"""
-	Find the program clang-cl.
-	"""
-	del(conf.env.CC)
-	del(conf.env.CXX)
-
-	llvm_path = None
-
+def get_llvm_paths(self):
+	llvm_path = []
 	if Utils.is_win32:
 		try:
 			llvm_key = Utils.winreg.OpenKey(Utils.winreg.HKEY_LOCAL_MACHINE,'SOFTWARE\\Wow6432Node\\LLVM\\LLVM')
 		except OSError:
 			llvm_key = Utils.winreg.OpenKey(Utils.winreg.HKEY_LOCAL_MACHINE, 'SOFTWARE\\LLVM\\LLVM')
 
-		llvm_path,type = Utils.winreg.QueryValueEx(llvm_key, '')
-		llvm_path = os.path.join(llvm_path, 'bin')
+		llvm_dir, _ = Utils.winreg.QueryValueEx(llvm_key, '')
+		if llvm_dir:
+			llvm_path.append(os.path.join(llvm_dir, 'bin'))
 
-	llvm_path = conf.environ.get('LLVM_PATH') or conf.env.LLVM_PATH
-	if llvm_path and llvm_path != 'bin':
-		paths = [llvm_path] + conf.env.PATH
-	else:
-		paths = conf.env.PATH
-
-	cc = conf.find_program('clang-cl', var='CC', path_list=paths)
-	conf.env.CC = conf.env.CXX = cc
-	conf.env.CC_NAME_SECONDARY = conf.env.CXX_NAME_SECONDARY = 'clang'
-
-	if not Utils.is_win32:
-		conf.env.MSVC_COMPILER = 'msvc'
-		conf.env.MSVC_VERSION = 19
-
-		if not conf.env.LINK_CXX:
-			conf.find_program('lld-link', path_list=paths, errmsg='lld-link was not found (linker)', var='LINK_CXX')
-
-		if not conf.env.LINK_CC:
-			conf.env.LINK_CC = conf.env.LINK_CXX
+	tmp = self.environ.get('LLVM_PATH') or self.env.LLVM_PATH
+	if tmp:
+		llvm_path.append(tmp)
+	llvm_path.append(self.env.PATH)
+	return llvm_path
 
 @conf
-def find_llvm_tools(conf):
+def find_clang_cl(self):
+	"""
+	Find the program clang-cl.
+	"""
+	del(self.env.CC)
+	del(self.env.CXX)
+
+	paths = self.get_llvm_paths()
+	cc = self.find_program('clang-cl', var='CC', path_list=paths)
+	self.env.CC = self.env.CXX = cc
+	self.env.CC_NAME_SECONDARY = self.env.CXX_NAME_SECONDARY = 'clang'
+
+	if not Utils.is_win32:
+		self.env.MSVC_COMPILER = 'msvc'
+		self.env.MSVC_VERSION = 19
+
+		if not self.env.LINK_CXX:
+			self.find_program('lld-link', path_list=paths, errmsg='lld-link was not found (linker)', var='LINK_CXX')
+
+		if not self.env.LINK_CC:
+			self.env.LINK_CC = self.env.LINK_CXX
+
+@conf
+def find_llvm_tools(self):
 	"""
 	Find the librarian, manifest tool, and resource compiler.
 	"""
-	conf.env.CC_NAME = conf.env.CXX_NAME = 'msvc'
+	self.env.CC_NAME = self.env.CXX_NAME = 'msvc'
 
-	llvm_path = conf.environ.get('LLVM_PATH') or conf.env.LLVM_PATH
-	if llvm_path and llvm_path != 'bin':
-		paths = [llvm_path] + conf.env.PATH
+	paths = self.get_llvm_paths()
+	llvm_path = self.environ.get('LLVM_PATH') or self.env.LLVM_PATH
+	if llvm_path:
+		paths = [llvm_path] + self.env.PATH
 	else:
-		paths = conf.env.PATH
+		paths = self.env.PATH
 
-	if not conf.env.AR:
-		stliblink = conf.find_program('llvm-lib', path_list=paths, var='AR')
+	if not self.env.AR:
+		stliblink = self.find_program('llvm-lib', path_list=paths, var='AR')
 		if not stliblink:
-			conf.fatal('Unable to find required program "llvm-lib"')
+			self.fatal('Unable to find required program "llvm-lib"')
 
-		conf.env.ARFLAGS = ['/nologo']
+		self.env.ARFLAGS = ['/nologo']
 
 	# We assume clang_cl to only be used with relatively new MSVC installations.
-	conf.env.MSVC_MANIFEST = True
-	conf.find_program('llvm-mt', path_list=paths, var='MT')
-	conf.env.MTFLAGS = ['/nologo']
+	self.env.MSVC_MANIFEST = True
+	self.find_program('llvm-mt', path_list=paths, var='MT')
+	self.env.MTFLAGS = ['/nologo']
 
 	try:
-		conf.load('winres')
+		self.load('winres')
 	except Errors.ConfigurationError:
 		Logs.warn('Resource compiler not found. Compiling resource file is disabled')
 
-def configure(conf):
+def configure(self):
 	if sys.platform == 'win32':
-		conf.autodetect(True)
-		conf.find_msvc()
+		self.autodetect(True)
+		self.find_msvc()
 	else:
-		conf.find_llvm_tools()
+		self.find_llvm_tools()
 
-	conf.find_clang_cl()
-	conf.msvc_common_flags()
-	conf.cc_load_tools()
-	conf.cxx_load_tools()
-	conf.cc_add_flags()
-	conf.cxx_add_flags()
-	conf.link_add_flags()
-	conf.visual_studio_add_flags()
+	self.find_clang_cl()
+	self.msvc_common_flags()
+	self.cc_load_tools()
+	self.cxx_load_tools()
+	self.cc_add_flags()
+	self.cxx_add_flags()
+	self.link_add_flags()
+	self.visual_studio_add_flags()