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, then make coverage does the following:

- make clean, then make check with CC=gcc & CXX=g++, and CFLAGS &&
  CXXFLAGS 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

@@ -7,6 +7,8 @@ Makefile.in
 *.la
 *~
 *.[1-9]
+*.gcda
+*.gcno
 .dirstamp
 
 /aclocal.m4
@@ -36,3 +38,5 @@ Makefile.in
 /src/tests/*.log
 /src/tests/*.trs
 /src/test-suite.log
+
+/src/coverage

Makefile.am

@@ -13,6 +13,9 @@ README.rst: src/vmod_re2.vcc
 	$(MAKE) -C src vmod_re2.man.rst
 	cp src/vmod_re2.man.rst README.rst
 
+coverage:
+	$(MAKE) $(AM_MAKEFLAGS) -C src coverage
+
 %.1 %.2 %.3 %.4 %.5 %.6 %.7 %.8 %.9:
 if HAVE_RST2MAN
 	${RST2MAN} $< $@

configure.ac

@@ -28,6 +28,22 @@ AC_ARG_WITH([rst2man],
 	[RST2MAN="$withval"],
 	AC_CHECK_PROGS(RST2MAN, [rst2man rst2man.py], []))
 
+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 INSTALL.rst]))
 
 PKG_CHECK_MODULES([RE2], [re2])

src/Makefile.am

@@ -52,6 +52,38 @@ AM_VTC_LOG_FLAGS = -Dvmod_re2="$(VMOD_RE2)"
 
 TESTS = @VMOD_TESTS@
 
+gcov: clean
+	$(AM_V_at)$(MAKE) $(AM_MAKEFLAGS) CC=gcc CXX=g++ \
+		CFLAGS="${AM_CFLAGS} --coverage -fno-inline -g -O0" \
+		CXXFLAGS="${AM_CXXFLAGS} --coverage -fno-inline -g -O0" check
+
+# Set QUIET=-q for non-verbose builds, otherwise set to empty.
+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_re2.vcc \
 	$(VMOD_TESTS)
@@ -61,4 +93,9 @@ CLEANFILES = \
 	$(builddir)/vcc_if.h \
 	$(builddir)/vmod_re2.rst \
 	$(builddir)/vmod_re2.man.rst \
-	$(builddir)/vmod_re2.3
+	$(builddir)/vmod_re2.3 \
+	$(builddir)/*.gcda \
+	$(builddir)/*.gcno
+
+clean-local:
+	@rm -rf $(builddir)/coverage