build: cmake: sdl: check for endbr64

Author: spalicki

cmake/SDL.cmake

@@ -36,7 +36,10 @@ macro(sdl_gnu_common_ccxx_flags var gnu_version)
     else()
         append(${var} "-fstack-protector-strong")
         if(NOT (${gnu_version} VERSION_LESS 8.0) AND (DNNL_TARGET_ARCH STREQUAL "X64"))
-            append(${var} "-fcf-protection=full")
+            check_toolchain_for_endbr64()
+            if(ENDBR64_SUPPORT_FLAG)
+                append(${var} "-fcf-protection=full")
+            endif()
         endif()
     endif()
 endmacro()

cmake/utils.cmake

@@ -174,3 +174,8 @@ function(find_libm var)
         find_library(${var} m REQUIRED)
     endif()
 endfunction()
+
+include(CheckCXXSourceCompiles)
+function(check_toolchain_for_endbr64)
+    check_cxx_source_compiles("int main() { asm volatile(\"endbr64\"); return 0; }" ENDBR64_SUPPORT_FLAG)
+endfunction()