Add autotool support for generating coverage reports.

configure checks if you have lcov & genhtml; these can be specified
with --with-lcov and/or --with-genhtml.

If they are available, the make target coverage can be executed:

- make clean, then make check with CC=gcc and CFLAGS set so that
  inputs for gcov/lcov are generated.

- lcov creates the src/coverage subdir and generates a targetfile
  there.

- genhtml generates HTML reports in src/coverage.

.gitignore

@@ -5,6 +5,8 @@ Makefile.in
 *.o
 *.lo
 *.la
+*.gcda
+*.gcno
 *~
 *.[1-9]
 .dirstamp
@@ -38,3 +40,5 @@ Makefile.in
 /src/tests/*.log
 /src/tests/*.trs
 /src/test-suite.log
+
+/src/coverage

Makefile.am

@@ -4,3 +4,6 @@ SUBDIRS = src
 
 DISTCHECK_CONFIGURE_FLAGS = \
 	VMOD_DIR='$${libdir}/varnish/vmods'
+
+coverage:
+	$(MAKE) $(AM_MAKEFLAGS) -C src coverage

configure.ac

@@ -35,6 +35,22 @@ AC_ARG_WITH([rst2man],
 	AC_CHECK_PROGS(RST2MAN, [rst2man rst2man.py], []))
 AM_CONDITIONAL(HAVE_RST2MAN, [test "x$RST2MAN" != "xno"])
 
+AC_ARG_WITH([lcov],
+	AS_HELP_STRING(
+		[--with-lcov=PATH],
+		[Location of lcov to generate coverage data (auto)]),
+	[LCOV="$withval"],
+	AC_CHECK_PROGS(LCOV, [lcov], []))
+AM_CONDITIONAL(HAVE_LCOV, [test -n "$LCOV"])
+
+AC_ARG_WITH([genhtml],
+	AS_HELP_STRING(
+		[--with-genhtml=PATH],
+		[Location of genhtml to generate coverage reports (auto)]),
+	[GENHTML="$withval"],
+	AC_CHECK_PROGS(GENHTML, [genhtml], []))
+AM_CONDITIONAL(HAVE_GENHTML, [test -n "$GENHTML"])
+
 m4_ifndef([VARNISH_PREREQ], AC_MSG_ERROR([Need varnish.m4 -- see README.rst]))
 
 PKG_CHECK_MODULES([LIBCRYPTO], [libcrypto])

src/Makefile.am

@@ -61,6 +61,36 @@ rfc8188_test_CFLAGS = $(AM_CFLAGS)
 
 TESTS += rfc8188_test
 
+gcov: clean
+	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) CC=gcc \
+		CFLAGS="${AM_CFLAGS} --coverage -fno-inline -g -O0" check
+
+QUIET_0 = -q
+QUIET_ = $(QUIET_@AM_DEFAULT_V@)
+QUIET = $(QUIET_@AM_V@)
+
+coverage/lcov.info: gcov
+if HAVE_LCOV
+	$(AM_V_at)@mkdir $(builddir)/coverage
+	$(AM_V_GEN) $(LCOV) $(QUIET) -c -d . -o  $(builddir)/coverage/lcov.info
+else
+	@echo "================================================="
+	@echo "You need lcov installed to generate coverage data"
+	@echo "================================================="
+	@false
+endif
+
+coverage: coverage/lcov.info
+if HAVE_GENHTML
+	$(AM_V_GEN) $(GENHTML) $(QUIET) $(builddir)/coverage/lcov.info \
+		-o  $(builddir)/coverage
+else
+	@echo "======================================================="
+	@echo "You need genhtml installed to generate coverage reports"
+	@echo "======================================================="
+	@false
+endif
+
 EXTRA_DIST = \
 	vmod_ece.vcc \
 	$(VMOD_TESTS)
@@ -70,4 +100,9 @@ CLEANFILES = \
 	$(builddir)/vcc_if.h \
 	$(builddir)/vmod_ece.rst \
 	$(builddir)/vmod_ece.man.rst \
-	$(builddir)/vmod_ece.3
+	$(builddir)/vmod_ece.3 \
+	$(builddir)/*.gcda \
+	$(builddir)/*.gcno
+
+clean-local:
+	@rm -rf $(builddir)/coverage