# This option enables -fsanitize=undefined for stage2 and stage3.
-STAGE2_CFLAGS += -fsanitize=undefined
-STAGE3_CFLAGS += -fsanitize=undefined
-POSTSTAGE1_LDFLAGS += -fsanitize=undefined -static-libubsan \
+STAGE2_CFLAGS += -fsanitize=undefined -DUBSAN_BOOTSTRAP
+STAGE3_CFLAGS += -fsanitize=undefined -DUBSAN_BOOTSTRAP
+POSTSTAGE1_LDFLAGS += -fsanitize=undefined -static-libubsan -DUBSAN_BOOTSTRAP \
-B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/ \
-B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/ubsan/ \
-B$$r/prev-$(TARGET_SUBDIR)/libsanitizer/ubsan/.libs