mk: add 'SANITIZE_UNDEFINED' option

'SANITIZE_UNDEFINED = yes' in 'target.mk' adds the '-fsanitize=undefined'
compiler flag and links the program with libubsan and libsanitizer_common.

Issue #3072

repos/base/mk/dep_prg.mk

@@ -23,6 +23,13 @@ ifeq ($(COVERAGE),yes)
 LIBS += libgcov
 endif
 
+#
+# Add libraries for undefined behavior sanitizer if requested
+#
+ifeq ($(SANITIZE_UNDEFINED),yes)
+LIBS += libubsan libsanitizer_common
+endif
+
 #
 # Include lib-import description files
 #

repos/base/mk/global.mk

@@ -119,6 +119,13 @@ endif
 CC_OPT += -fprofile-arcs -ftest-coverage -fprofile-dir=$(PROFILE_DIR)
 endif
 
+#
+# Enable the undefined behavior sanitizer if requested
+#
+ifeq ($(SANITIZE_UNDEFINED),yes)
+CC_OPT += -fsanitize=undefined
+endif
+
 #
 # Default optimization and warning levels
 #