safestring: Allow clean along with other targets

Allow clean to be used along with other targets by processing
the clean first and then all other targets.

Signed-off-by: Mark Rustad <MRustad@gmail.com>

makefile

@@ -11,6 +11,11 @@ OTDIR=objtest
 SRCDIR=safeclib
 TESTDIR=unittests
 
+CLEANGOAL := $(filter clean,${MAKECMDGOALS})
+OTHERGOALS := $(filter-out clean,${MAKECMDGOALS})
+
+ifeq (${CLEANGOAL},)
+
 .PHONY: all
 all: libsafestring.a safestringtest
 
@@ -84,13 +89,22 @@ ${ODIR}:
 ${OTDIR}:
  ${MKDIR_P} ${OTDIR}
 
+-include $(wildcard ${ODIR}/*.d)
+-include $(wildcard ${OTDIR}/*.d)
+
+else
+
 .PHONY: clean
 
 clean:
  rm -f *~ core ${INCDIR}/*~
  rm -rf ${ODIR} ${OTDIR}
  rm -f libsafestring.a
  rm -f safestringtest
+ifneq (${OTHERGOALS},)
+ ${MAKE} ${OTHERGOALS}
+endif
 
--include $(wildcard ${ODIR}/*.d)
--include $(wildcard ${OTDIR}/*.d)
+%: ;
+
+endif # CLEANGOAL