Index: docs/LibFuzzer.rst
===================================================================
--- docs/LibFuzzer.rst
+++ docs/LibFuzzer.rst
@@ -639,13 +639,16 @@
 LibFuzzer is built as a part of LLVM project by default on macos and Linux.
 Users of other operating systems can explicitly request compilation using
 ``-DLIBFUZZER_ENABLE=YES`` flag.
-Tests are run using ``check-fuzzer`` target from the build directory
-which was configured with ``-DLIBFUZZER_ENABLE_TESTS=ON`` flag.
+Tests are run using ``check-fuzzer`` target from the build directory,
+provided Clang is checked out in your source tree:
 
 .. code-block:: console
 
     ninja check-fuzzer
 
+If you wish to use a different Clang, you can specify it using
+``LIBFUZZER_TEST_COMPILER`` environment variable.
+
 
 Fuzzing components of LLVM
 ==========================
Index: lib/Fuzzer/CMakeLists.txt
===================================================================
--- lib/Fuzzer/CMakeLists.txt
+++ lib/Fuzzer/CMakeLists.txt
@@ -22,7 +22,6 @@
 # Compile libFuzzer if the compilation is specifically requested, OR
 # if the platform is known to be working.
 set(LIBFUZZER_ENABLE ${LIBFUZZER_ENABLED_CHECK} CACHE BOOL "Build libFuzzer and its tests")
-set(LIBFUZZER_ENABLE_TESTS OFF CACHE BOOL "Build libFuzzer and its tests")
 
 if (LLVM_USE_SANITIZE_COVERAGE)
   set(CMAKE_CXX_FLAGS
@@ -71,7 +70,7 @@
   add_custom_command(TARGET check-fuzzer
     COMMAND cmake -E echo "check-fuzzer is disalbed on Windows")
 else()
-  if (LLVM_INCLUDE_TESTS AND LIBFUZZER_ENABLE_TESTS)
+  if (LLVM_INCLUDE_TESTS)
     add_subdirectory(test)
   endif()
 endif()
Index: lib/Fuzzer/test/CMakeLists.txt
===================================================================
--- lib/Fuzzer/test/CMakeLists.txt
+++ lib/Fuzzer/test/CMakeLists.txt
@@ -13,6 +13,9 @@
 # Unit tests
 ###############################################################################
 
+# Do not register fuzzer tests under check-all.
+set(EXCLUDE_FROM_ALL On)
+
 add_custom_target(FuzzerUnitTests)
 set_target_properties(FuzzerUnitTests PROPERTIES FOLDER "libFuzzer tests")
 
@@ -44,8 +47,7 @@
 
 # Use just-built Clang to compile/link tests on all platforms, except for
 # Windows where we need to use clang-cl instead.
-set(LIBFUZZER_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang)
-set(LIBFUZZER_TEST_CXX_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang++)
+set(LIBFUZZER_TEST_COMPILER ${LLVM_RUNTIME_OUTPUT_INTDIR}/clang CACHE PATH "Path to Clang compiler")
 
 # LIT-based libFuzzer tests.
 configure_lit_site_cfg(
@@ -63,4 +65,4 @@
   ${CMAKE_CURRENT_BINARY_DIR}
   DEPENDS LLVMFuzzer-Unittest)
 
-add_dependencies(check-fuzzer LLVMFuzzer asan clang llvm-symbolizer FileCheck sancov not)
+add_dependencies(check-fuzzer LLVMFuzzer llvm-symbolizer FileCheck sancov not)
Index: lib/Fuzzer/test/lit.cfg
===================================================================
--- lib/Fuzzer/test/lit.cfg
+++ lib/Fuzzer/test/lit.cfg
@@ -54,7 +54,8 @@
 config.substitutions.append(('%build_dir', config.cmake_binary_dir))
 
 def generate_compiler_cmd(is_cpp=True, fuzzer_enabled=True):
-  compiler_cmd = config.cpp_compiler if is_cpp else config.c_compiler
+  compiler_cmd = config.c_compiler
+  driver_mode_cmd = '--driver-mode=g++' if is_cpp else ''
   std_cmd = '-std=c++11' if is_cpp else ''
   sanitizers = ['address']
   if fuzzer_enabled:
@@ -63,8 +64,9 @@
   isysroot_cmd = ('-isysroot %s' % config.osx_sysroot
       ) if 'darwin' in config.target_triple else ''
   include_cmd = '-I%s/../.' % config.test_source_root
-  return '%s %s -gline-tables-only %s %s %s' % (
-      compiler_cmd, std_cmd, isysroot_cmd, sanitizers_cmd, include_cmd)
+  return '%s %s %s -gline-tables-only %s %s %s' % (
+      compiler_cmd, driver_mode_cmd, std_cmd,
+      isysroot_cmd, sanitizers_cmd, include_cmd)
 
 config.substitutions.append(('%cpp_compiler',
       generate_compiler_cmd(is_cpp=True, fuzzer_enabled=True)
Index: lib/Fuzzer/test/lit.site.cfg.in
===================================================================
--- lib/Fuzzer/test/lit.site.cfg.in
+++ lib/Fuzzer/test/lit.site.cfg.in
@@ -1,7 +1,6 @@
 config.test_exec_root = "@CMAKE_CURRENT_BINARY_DIR@"
 config.llvm_tools_dir = "@LLVM_TOOLS_DIR@"
 config.has_lsan = True if @HAS_LSAN@ == 1 else False
-config.cpp_compiler = "@LIBFUZZER_TEST_CXX_COMPILER@"
 config.c_compiler = "@LIBFUZZER_TEST_COMPILER@"
 config.osx_sysroot = "@CMAKE_OSX_SYSROOT@"
 config.cmake_binary_dir = "@CMAKE_BINARY_DIR@"