+if test "$enable_ubsan" = "yes" || test "$enable_ubsan" = "probe"; then
+ AC_PACKAGE_CHECK_UBSAN
+fi
+if test "$enable_ubsan" = "yes" && test "$have_ubsan" != "yes"; then
+ AC_MSG_ERROR([UBSAN not supported by compiler.])
+fi
+
+if test "$enable_addrsan" = "yes" || test "$enable_addrsan" = "probe"; then
+ AC_PACKAGE_CHECK_ADDRSAN
+fi
+if test "$enable_addrsan" = "yes" && test "$have_addrsan" != "yes"; then
+ AC_MSG_ERROR([ADDRSAN not supported by compiler.])
+fi
+
+if test "$enable_threadsan" = "yes" || test "$enable_threadsan" = "probe"; then
+ AC_PACKAGE_CHECK_THREADSAN
+fi
+if test "$enable_threadsan" = "yes" && test "$have_threadsan" != "yes"; then
+ AC_MSG_ERROR([THREADSAN not supported by compiler.])
+fi
+
+if test "$have_threadsan" = "yes" && test "$have_addrsan" = "yes"; then
+ AC_MSG_WARN([ADDRSAN and THREADSAN are not known to work together.])
+fi
+
+if test "$enable_lto" = "yes" || test "$enable_lto" = "probe"; then
+ AC_PACKAGE_CHECK_LTO
+fi
+if test "$enable_lto" = "yes" && test "$have_lto" != "yes"; then
+ AC_MSG_ERROR([LTO not supported by compiler.])
+fi
+
+AC_PACKAGE_CHECK_RETPOLINE