diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -267,7 +267,11 @@
   append_string_if(COMPILER_RT_HAS_WX_FLAG /WX CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif()
 
-append_string_if(COMPILER_RT_HAS_STD_CXX14_FLAG -std=c++14 CMAKE_CXX_FLAGS)
+if (COMPILER_RT_HAS_STD_CXX17_FLAG)
+  string(APPEND CMAKE_CXX_FLAGS " -std=c++17")
+elseif(COMPILER_RT_HAS_STD_CXX14_FLAG)
+  string(APPEND CMAKE_CXX_FLAGS " -std=c++14")
+endif()
 
 # Emulate C99 and C++11's __func__ for MSVC prior to 2013 CTP.
 if(NOT COMPILER_RT_HAS_FUNC_SYMBOL)
diff --git a/compiler-rt/cmake/config-ix.cmake b/compiler-rt/cmake/config-ix.cmake
--- a/compiler-rt/cmake/config-ix.cmake
+++ b/compiler-rt/cmake/config-ix.cmake
@@ -69,6 +69,7 @@
 check_cxx_compiler_flag(-fno-rtti            COMPILER_RT_HAS_FNO_RTTI_FLAG)
 check_cxx_compiler_flag("-Werror -fno-function-sections" COMPILER_RT_HAS_FNO_FUNCTION_SECTIONS_FLAG)
 check_cxx_compiler_flag(-std=c++14           COMPILER_RT_HAS_STD_CXX14_FLAG)
+check_cxx_compiler_flag(-std=c++17           COMPILER_RT_HAS_STD_CXX17_FLAG) # C++17 takes precedence.
 check_cxx_compiler_flag(-ftls-model=initial-exec COMPILER_RT_HAS_FTLS_MODEL_INITIAL_EXEC)
 check_cxx_compiler_flag(-fno-lto             COMPILER_RT_HAS_FNO_LTO_FLAG)
 check_cxx_compiler_flag(-fno-profile-generate COMPILER_RT_HAS_FNO_PROFILE_GENERATE_FLAG)
@@ -167,7 +168,7 @@
 set(VERS_OPTION "-Wl,--version-script,${DUMMY_VERS}")
 if(COMPILER_RT_HAS_GNU_VERSION_SCRIPT_COMPAT)
   # Solaris 11.4 ld only supports --version-script with
-  # -z gnu-version-script-compat. 
+  # -z gnu-version-script-compat.
   string(APPEND VERS_OPTION " ${VERS_COMPAT_OPTION}")
 endif()
 check_linker_flag("${VERS_OPTION}" COMPILER_RT_HAS_VERSION_SCRIPT)