[cmake] Enable explicitly exceptions

CMakeLists.txt

@@ -82,19 +82,22 @@ endif ()
 include(CheckCXXCompilerFlag)
 
 if (MSVC)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4251 /wd4141")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /wd4018 /wd4267 /wd4715 /wd4146 /wd4129")
+  add_compile_options(/wd4251 /wd4141)
+  add_compile_options(/wd4018 /wd4267 /wd4715 /wd4146 /wd4129)
+  add_compile_options(/EHsc)
+else()
+  add_compile_options(-fexceptions)
 endif ()
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU" OR CMAKE_CXX_COMPILER_ID MATCHES "Intel")
     if(NOT XEUS_CPP_EMSCRIPTEN_WASM_BUILD)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wunused-parameter -Wextra -Wreorder")
+        add_compile_options(-Wunused-parameter -Wextra -Wreorder)
     endif()
 
 
     CHECK_CXX_COMPILER_FLAG("-std=c++17" HAS_CPP_17_FLAG)
     if (HAS_CPP_17_FLAG)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++17")
+        add_compile_options(-std=c++17)
     else ()
         message(FATAL_ERROR "Unsupported compiler -- xeus requires C++17 support!")
     endif ()