Index: flang/CMakeLists.txt
===================================================================
--- flang/CMakeLists.txt
+++ flang/CMakeLists.txt
@@ -236,7 +236,11 @@
   ${FLANG_BINARY_DIR}/include/flang/Config/config.h)
 
 # Add global F18 flags.
-set(CMAKE_CXX_FLAGS "-fno-rtti -fno-exceptions -pedantic -Wall -Wextra -Werror -Wcast-qual -Wimplicit-fallthrough -Wdelete-non-virtual-dtor ${CMAKE_CXX_FLAGS}")
+if(MSVC)
+  set(CMAKE_CXX_FLAGS "/GR- /EHs-c- /Wall ${CMAKE_CXX_FLAGS}")
+else()
+  set(CMAKE_CXX_FLAGS "-fno-rtti -fno-exceptions -pedantic -Wall -Wextra -Werror -Wcast-qual -Wimplicit-fallthrough -Wdelete-non-virtual-dtor ${CMAKE_CXX_FLAGS}")
+endif()
 
 # Builtin check_cxx_compiler_flag doesn't seem to work correctly
 macro(check_compiler_flag flag resultVar)