unit-tests: Separate test runner to a library, reusable by other tests

Other users may make use of the noinst libtest.la helper library to implement
unit tests. For libstrongswan, tests.[ch] provide the configuration for test
runner to perform unit tests in a simple manner.

src/libstrongswan/tests/Makefile.am

@@ -1,9 +1,24 @@
-TESTS = test_runner
+check_LTLIBRARIES = libtest.la
+
+libtest_la_SOURCES = \
+  test_suite.c test_suite.h \
+  test_runner.c test_runner.h
+
+libtest_la_CFLAGS = \
+  -I$(top_srcdir)/src/libstrongswan \
+  @COVERAGE_CFLAGS@
+
+libtest_la_LDFLAGS = @COVERAGE_LDFLAGS@
+libtest_la_LIBADD = \
+  $(top_builddir)/src/libstrongswan/libstrongswan.la \
+  $(PTHREADLIB)
+
+
+TESTS = tests
 
 check_PROGRAMS = $(TESTS)
 
-test_runner_SOURCES = \
-  test_runner.c test_runner.h test_suite.c test_suite.h \
+tests_SOURCES = tests.h tests.c \
   suites/test_linked_list.c \
   suites/test_enumerator.c \
   suites/test_linked_list_enumerator.c \
@@ -26,13 +41,14 @@ test_runner_SOURCES = \
   suites/test_asn1.c \
   suites/test_printf.c
 
-test_runner_CFLAGS = \
+tests_CFLAGS = \
   -I$(top_srcdir)/src/libstrongswan \
+  -I$(top_srcdir)/src/libstrongswan/tests \
   -DPLUGINDIR=\""$(top_builddir)/src/libstrongswan/plugins\"" \
   -DPLUGINS=\""${s_plugins}\"" \
   @COVERAGE_CFLAGS@
 
-test_runner_LDFLAGS = @COVERAGE_LDFLAGS@
-test_runner_LDADD = \
+tests_LDFLAGS = @COVERAGE_LDFLAGS@
+tests_LDADD = \
   $(top_builddir)/src/libstrongswan/libstrongswan.la \
-  $(PTHREADLIB)
+  libtest.la