Index: include/clang/Driver/Options.td
===================================================================
--- include/clang/Driver/Options.td
+++ include/clang/Driver/Options.td
@@ -2705,6 +2705,7 @@
     Group<clang_ignored_gcc_optimization_f_Group>;
 defm spec_constr_count : BooleanFFlag<"spec-constr-count">, Group<clang_ignored_f_Group>;
 defm stack_check : BooleanFFlag<"stack-check">, Group<clang_ignored_f_Group>;
+defm stack_clash_protection : BooleanFFlag<"stack-clash-protection">, Group<clang_ignored_f_Group>;
 defm strength_reduce :
     BooleanFFlag<"strength-reduce">, Group<clang_ignored_gcc_optimization_f_Group>;
 defm tls_model : BooleanFFlag<"tls-model">, Group<clang_ignored_f_Group>;
Index: test/Driver/clang_f_opts.c
===================================================================
--- test/Driver/clang_f_opts.c
+++ test/Driver/clang_f_opts.c
@@ -284,6 +284,7 @@
 // RUN:     -ffriend-injection                                                \
 // RUN:     -fno-implement-inlines -fimplement-inlines                        \
 // RUN:     -fstack-check                                                     \
+// RUN:     -fstack-clash-protection                                          \
 // RUN:     -fforce-addr                                                      \
 // RUN:     -malign-functions=100                                             \
 // RUN:     -malign-loops=100                                                 \