Index: cmake/Modules/AddCompilerRT.cmake
===================================================================
--- cmake/Modules/AddCompilerRT.cmake
+++ cmake/Modules/AddCompilerRT.cmake
@@ -491,6 +491,8 @@
                -DCMAKE_INSTALL_PREFIX:PATH=<INSTALL_DIR>
                -DLLVM_PATH=${LLVM_MAIN_SRC_DIR}
                -DLIBCXX_STANDALONE_BUILD=On
+               -DLIBCXX_ENABLE_EXCEPTIONS=OFF
+               -DLIBCXX_CXX_ABI=none
     LOG_BUILD 1
     LOG_CONFIGURE 1
     LOG_INSTALL 1
Index: lib/fuzzer/CMakeLists.txt
===================================================================
--- lib/fuzzer/CMakeLists.txt
+++ lib/fuzzer/CMakeLists.txt
@@ -33,6 +33,10 @@
 
 set(LIBFUZZER_CFLAGS ${SANITIZER_COMMON_CFLAGS})
 
+if(COMPILER_RT_LIBCXX_PATH)
+  list(APPEND LIBFUZZER_CFLAGS -nostdinc++ -D_LIBCPP_ABI_VERSION=__Fuzzer)
+endif()
+
 append_list_if(COMPILER_RT_HAS_OMIT_FRAME_POINTER_FLAG -fno-omit-frame-pointer LIBFUZZER_CFLAGS)
 
 if (CMAKE_CXX_FLAGS MATCHES "fsanitize-coverage")
@@ -75,6 +79,57 @@
   CFLAGS ${LIBFUZZER_CFLAGS}
   PARENT_TARGET fuzzer)
 
+macro(partially_link_lib name dir)
+  add_custom_command(TARGET ${name} POST_BUILD
+    COMMAND ${CMAKE_LINKER} --whole-archive "$<TARGET_LINKER_FILE:${name}>" --no-whole-archive ${LIBCXX_${arch}_PREFIX}/lib/libc++.a -r -o Fuzzer_main.o
+    COMMAND ${CMAKE_COMMAND} -E remove "$<TARGET_LINKER_FILE:${name}>"
+    COMMAND ${CMAKE_AR} qcs "$<TARGET_LINKER_FILE:${name}>" Fuzzer_main.o
+    WORKING_DIRECTORY ${dir}
+  )
+endmacro()
+
+if(COMPILER_RT_LIBCXX_PATH)
+  foreach(arch ${FUZZER_SUPPORTED_ARCH})
+    get_target_flags_for_arch(${arch} TARGET_CFLAGS)
+    set(LIBCXX_${arch}_PREFIX ${CMAKE_CURRENT_BINARY_DIR}/libcxx_fuzzer_${arch})
+    add_custom_libcxx(libcxx_fuzzer_${arch} ${LIBCXX_${arch}_PREFIX}
+      CFLAGS ${TARGET_CFLAGS} -D_LIBCPP_ABI_VERSION=__Fuzzer -D_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS=1 -fvisibility=hidden)
+    target_compile_options(RTfuzzer.${arch} PRIVATE
+      -isystem ${CMAKE_CURRENT_BINARY_DIR}/libcxx_fuzzer_${arch}/include/c++/v1
+    )
+    add_dependencies(RTfuzzer.${arch} libcxx_fuzzer_${arch})
+    target_compile_options(RTfuzzer_main.${arch} PRIVATE
+      -isystem ${CMAKE_CURRENT_BINARY_DIR}/libcxx_fuzzer_${arch}/include/c++/v1
+    )
+    add_dependencies(RTfuzzer_main.${arch} libcxx_fuzzer_${arch})
+    set(cxx_${arch}_merge_dir "${CMAKE_CURRENT_BINARY_DIR}/cxx_${arch}_merge.dir")
+    file(MAKE_DIRECTORY ${cxx_${arch}_merge_dir})
+    add_custom_command(TARGET clang_rt.fuzzer-${arch} POST_BUILD
+      COMMAND ${CMAKE_LINKER} --whole-archive "$<TARGET_LINKER_FILE:clang_rt.fuzzer-${arch}>" --no-whole-archive ${LIBCXX_${arch}_PREFIX}/lib/libc++.a -r -o Fuzzer_main.o
+      COMMAND ${CMAKE_COMMAND} -E remove "$<TARGET_LINKER_FILE:clang_rt.fuzzer-${arch}>"
+      COMMAND ${CMAKE_AR} qcs "$<TARGET_LINKER_FILE:clang_rt.fuzzer-${arch}>" Fuzzer_main.o
+      WORKING_DIRECTORY ${cxx_${arch}_merge_dir}
+    )
+    add_custom_command(TARGET clang_rt.fuzzer_no_main-${arch} POST_BUILD
+      COMMAND ${CMAKE_LINKER} --whole-archive "$<TARGET_LINKER_FILE:clang_rt.fuzzer_no_main-${arch}>" --no-whole-archive ${LIBCXX_${arch}_PREFIX}/lib/libc++.a -r -o Fuzzer.o
+      COMMAND ${CMAKE_COMMAND} -E remove "$<TARGET_LINKER_FILE:clang_rt.fuzzer_no_main-${arch}>"
+      COMMAND ${CMAKE_AR} qcs "$<TARGET_LINKER_FILE:clang_rt.fuzzer_no_main-${arch}>" Fuzzer.o
+      WORKING_DIRECTORY ${cxx_${arch}_merge_dir}
+    )
+
+    # TODO: CMake 3.4 doesn't support the use of object libraries from custom
+    # commands. When LLVM moves to CMake 3.9, we could instead use the command
+    # below to create the object file directly without relinking the archive.
+    #
+    # add_custom_command(
+    #   OUTPUT Fuzzer.o
+    #   COMMAND ld -r $<TARGET_OBJECTS:RTFuzzer> ${LIBCXX_${arch}_PREFIX}/lib/libc++.a -o Fuzzer.o
+    #   DEPENDS $<TARGET_OBJECTS:RTFuzzer>
+    #   COMMAND_EXPAND_LISTS
+    # )
+  endforeach()
+endif()
+
 if(COMPILER_RT_INCLUDE_TESTS)
   add_subdirectory(tests)
 endif()
Index: lib/fuzzer/tests/CMakeLists.txt
===================================================================
--- lib/fuzzer/tests/CMakeLists.txt
+++ lib/fuzzer/tests/CMakeLists.txt
@@ -18,6 +18,10 @@
   list(APPEND LIBFUZZER_UNITTEST_LINK_FLAGS -lstdc++ -lpthread)
 endif()
 
+if(COMPILER_RT_LIBCXX_PATH)
+  list(APPEND LIBFUZZER_UNITTEST_CFLAGS -nostdinc++ -D_LIBCPP_ABI_VERSION=__Fuzzer)
+endif()
+
 foreach(arch ${FUZZER_SUPPORTED_ARCH})
   set(LIBFUZZER_TEST_RUNTIME RTFuzzerTest.${arch})
   if(APPLE)
@@ -33,14 +37,22 @@
     ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
     FOLDER "Compiler-RT Runtime tests")
 
+  if(COMPILER_RT_LIBCXX_PATH)
+    set(LIBFUZZER_TEST_RUNTIME_DEPS libcxx_fuzzer_${arch})
+    set(LIBFUZZER_TEST_RUNTIME_CFLAGS
+      -isystem ${CMAKE_CURRENT_BINARY_DIR}/../libcxx_fuzzer_${arch}/include/c++/v1)
+    set(LIBFUZZER_TEST_RUNTIME_LINK_FLAGS
+      ${CMAKE_CURRENT_BINARY_DIR}/../libcxx_fuzzer_${arch}/lib/libc++.a)
+  endif()
+
   set(FuzzerTestObjects)
   generate_compiler_rt_tests(FuzzerTestObjects
     FuzzerUnitTests "Fuzzer-${arch}-Test" ${arch}
     SOURCES FuzzerUnittest.cpp ${COMPILER_RT_GTEST_SOURCE}
     RUNTIME ${LIBFUZZER_TEST_RUNTIME}
-    DEPS gtest
-    CFLAGS ${LIBFUZZER_UNITTEST_CFLAGS}
-    LINK_FLAGS ${LIBFUZZER_UNITTEST_LINK_FLAGS})
+    DEPS gtest ${LIBFUZZER_TEST_RUNTIME_DEPS}
+    CFLAGS ${LIBFUZZER_UNITTEST_CFLAGS} ${LIBFUZZER_TEST_RUNTIME_CFLAGS}
+    LINK_FLAGS ${LIBFUZZER_UNITTEST_LINK_FLAGS} ${LIBFUZZER_TEST_RUNTIME_LINK_FLAGS})
   set_target_properties(FuzzerUnitTests PROPERTIES
     RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
 endforeach()
Index: test/fuzzer/CMakeLists.txt
===================================================================
--- test/fuzzer/CMakeLists.txt
+++ test/fuzzer/CMakeLists.txt
@@ -8,36 +8,44 @@
   list(APPEND LIBFUZZER_TEST_DEPS FuzzerUnitTests)
 endif()
 
-set(LIBFUZZER_TESTSUITES)
-
+add_custom_target(check-fuzzer)
 
 if(COMPILER_RT_INCLUDE_TESTS)
   # libFuzzer unit tests.
   configure_lit_site_cfg(
     ${CMAKE_CURRENT_SOURCE_DIR}/unit/lit.site.cfg.in
     ${CMAKE_CURRENT_BINARY_DIR}/unit/lit.site.cfg)
-  list(APPEND LIBFUZZER_TESTSUITES ${CMAKE_CURRENT_BINARY_DIR}/unit)
+  add_lit_testsuite(check-fuzzer-unit "Running Fuzzer unit tests"
+    ${CMAKE_CURRENT_BINARY_DIR}/unit
+    DEPENDS ${LIBFUZZER_TEST_DEPS})
+  set_target_properties(check-fuzzer-unit PROPERTIES FOLDER "Compiler-RT Tests")
+  add_dependencies(check-fuzzer check-fuzzer-unit)
 endif()
 
-foreach(arch ${FUZZER_SUPPORTED_ARCH})
-  set(LIBFUZZER_TEST_COMPILER ${COMPILER_RT_TEST_COMPILER})
-  get_test_cc_for_arch(${arch} LIBFUZZER_TEST_COMPILER LIBFUZZER_TEST_FLAGS)
-
-  string(TOUPPER ${arch} ARCH_UPPER_CASE)
-  set(CONFIG_NAME ${ARCH_UPPER_CASE}${OS_NAME}Config)
-
-  # LIT-based libFuzzer tests.
-  configure_lit_site_cfg(
-    ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
-    ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
-    )
-  list(APPEND LIBFUZZER_TESTSUITES ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME})
-
+foreach(stdlib IN ITEMS stdlibc++ libc++)
+  string(REPLACE "+" "x" stdlib_name ${stdlib})
+  foreach(arch ${FUZZER_SUPPORTED_ARCH})
+    set(LIBFUZZER_TEST_COMPILER ${COMPILER_RT_TEST_COMPILER})
+    get_test_cc_for_arch(${arch} LIBFUZZER_TEST_COMPILER LIBFUZZER_TEST_FLAGS)
+
+    set(LIBFUZZER_TEST_STDLIB ${stdlib})
+    string(TOUPPER ${stdlib_name} STDLIB_UPPER_CASE)
+
+    string(TOUPPER ${arch} ARCH_UPPER_CASE)
+    set(CONFIG_NAME ${ARCH_UPPER_CASE}${STDLIB_UPPER_CASE}${OS_NAME}Config)
+
+    # LIT-based libFuzzer tests.
+    configure_lit_site_cfg(
+      ${CMAKE_CURRENT_SOURCE_DIR}/lit.site.cfg.in
+      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}/lit.site.cfg
+      )
+
+    add_lit_testsuite(check-fuzzer-${stdlib_name} "Running Fuzzer ${stdlib} tests"
+      ${CMAKE_CURRENT_BINARY_DIR}/${CONFIG_NAME}
+      DEPENDS ${LIBFUZZER_TEST_DEPS})
+    set_target_properties(check-fuzzer-${stdlib_name} PROPERTIES FOLDER "Compiler-RT Tests")
+    add_dependencies(check-fuzzer check-fuzzer-${stdlib_name})
+  endforeach()
 endforeach()
 
 set(EXCLUDE_FROM_ALL ON)
-
-add_lit_testsuite(check-fuzzer "Running Fuzzer tests"
-  ${LIBFUZZER_TESTSUITES}
-  DEPENDS ${LIBFUZZER_TEST_DEPS})
-set_target_properties(check-fuzzer PROPERTIES FOLDER "Compiler-RT Tests")
Index: test/fuzzer/lit.cfg
===================================================================
--- test/fuzzer/lit.cfg
+++ test/fuzzer/lit.cfg
@@ -7,6 +7,8 @@
 config.suffixes = ['.test']
 config.test_source_root = os.path.dirname(__file__)
 
+config.environment['LD_LIBRARY_PATH'] = config.llvm_library_dir
+
 # Choose between lit's internal shell pipeline runner and a real shell.  If
 # LIT_USE_INTERNAL_SHELL is in the environment, we use that as an override.
 use_lit_shell = os.environ.get("LIT_USE_INTERNAL_SHELL")
@@ -51,7 +53,10 @@
 
 def generate_compiler_cmd(is_cpp=True, fuzzer_enabled=True):
   compiler_cmd = config.c_compiler
-  link_cmd = '-lc++' if 'darwin' in config.target_triple else '-lstdc++'
+  if config.clang and config.stdlib == 'libc++':
+    link_cmd = '-stdlib=libc++ -lc++'
+  else:
+    link_cmd = '-lc++' if 'darwin' in config.target_triple else '-lstdc++'
   std_cmd = '-std=c++11' if is_cpp else ''
   sanitizers = ['address']
   if fuzzer_enabled:
Index: test/fuzzer/lit.site.cfg.in
===================================================================
--- test/fuzzer/lit.site.cfg.in
+++ test/fuzzer/lit.site.cfg.in
@@ -5,9 +5,11 @@
 config.cpp_compiler = "@LIBFUZZER_TEST_COMPILER@"
 config.target_flags = "@LIBFUZZER_TEST_FLAGS@"
 config.c_compiler = "@LIBFUZZER_TEST_COMPILER@"
+config.stdlib = "@LIBFUZZER_TEST_STDLIB@"
 
 config.osx_sysroot_flag = "@OSX_SYSROOT_FLAG@"
 config.cmake_binary_dir = "@CMAKE_BINARY_DIR@"
+config.llvm_library_dir = "@LLVM_LIBRARY_DIR@"
 config.target_triple = "@TARGET_TRIPLE@"
 
 # Load common config for all compiler-rt lit tests.