Makefile: restore lcov helper rules

Run 'make lcov' to produce the coverage report in the lcov/.
This requires lcov installed and the --enable-coverage configure flag.

Makefile.am

@@ -983,6 +983,28 @@ install-exec-hook:
 uninstall-hook:
 	rm -f -- "$(DESTDIR)$(vlclibdir)/plugins/plugins.dat"
 
+###############################################################################
+# Test coverage
+###############################################################################
+
+lcov-raw.out:
+	$(MAKE) $(AM_MAKEFLAGS) all
+	lcov -z -d .
+	$(MAKE) $(AM_MAKEFLAGS) check
+	lcov -c -d . -o lcov-raw.out
+
+lcov.out: lcov-raw.out
+	lcov -r lcov-raw.out -o lcov.out \
+		'*test*' 'contrib/*' '/usr/include/*'
+
+lcov: lcov.out
+	rm -Rf lcov lcov.tmp
+	genhtml lcov.out -o lcov.tmp
+	mv lcov.tmp lcov
+
+.PHONY: lcov-raw.out
+
+
 ###############################################################################
 # PO translation files update
 ###############################################################################

modules/access/rtp/Makefile.am

@@ -32,18 +32,3 @@ librtp_plugin_la_CFLAGS += $(GCRYPT_CFLAGS)
 librtp_plugin_la_LIBADD += libvlc_srtp.la $(GCRYPT_LIBS)
 librtp_plugin_la_DEPENDENCIES += libvlc_srtp.la
 endif
-
-#lcov-run:
-#	rm -Rf *.gcda lcov
-#	$(MAKE) $(AM_MAKEFLAGS) check
-#
-#lcov-pre.out:
-#	lcov -c -d . -o lcov.tmp
-#
-#lcov.out: lcov-pre.out
-#	lcov -r lcov.tmp '*test*' > lcov.out
-#
-#lcov: lcov.out
-#	genhtml lcov.out -o lcov
-#
-#.PHONY: lcov-run