makefile: Clean up compiler flags
diff --git a/Makefile.am b/Makefile.am
index 9bddc5e..26cc8db 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,4 +1,13 @@
 ACLOCAL_AMFLAGS = -I m4
 
+export AM_CPPFLAGS = -I$(abs_builddir)/src -I$(abs_srcdir)/src \
+                     $(SYSTEMD_CFLAGS) $(CODE_COVERAGE_CPPFLAGS)
+export AM_CFLAGS = $(CODE_COVERAGE_CFLAGS)
+export AM_CXXFLAGS = $(CODE_COVERAGE_CXXFLAGS)
+
+export COMMON_LIBS = $(SYSTEMD_LIBS) $(CODE_COVERAGE_LIBS)
+export SDEVENTPLUS_LIBS = $(abs_builddir)/src/libsdeventplus.la $(COMMON_LIBS)
+
+
 EXTRA_DIST = LICENSE MAINTAINERS README.md
 SUBDIRS = src example test