unit-tests: Add facility to register testable functions

These can be defined in plugins, or other parts of the tested libraries.
They can even be static.

src/libstrongswan/utils/test.c

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "test.h"
+
+#include <library.h>
+
+/**
+ * A collection of testable functions
+ */
+hashtable_t *testable_functions;
+
+/*
+ * Described in header.
+ */
+void testable_function_register(char *name, void *fn)
+{
+	if (testable_functions)
+	{
+		bool old = FALSE;
+		if (lib->leak_detective)
+		{
+			old = lib->leak_detective->set_state(lib->leak_detective, FALSE);
+		}
+		if (fn)
+		{
+			testable_functions->put(testable_functions, name, fn);
+		}
+		else
+		{
+			testable_functions->remove(testable_functions, name);
+		}
+		if (lib->leak_detective)
+		{
+			lib->leak_detective->set_state(lib->leak_detective, old);
+		}
+	}
+}

src/libstrongswan/utils/test.h

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2013 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup test test
+ * @{ @ingroup utils
+ */
+
+#ifndef TEST_H_
+#define TEST_H_
+
+#include "collections/hashtable.h"
+
+/**
+ * Collection of testable functions.
+ *
+ * @note Is initialized only if libtest is loaded.
+ */
+extern hashtable_t *testable_functions;
+
+/**
+ * Register a (possibly static) function so that it can be called from tests.
+ *
+ * @param name		name (namespace/function)
+ * @param fn		function to register (set to NULL to unregister)
+ */
+void testable_function_register(char *name, void *fn);
+
+/**
+ * Macro to automatically register/unregister a function that can be called
+ * from tests.
+ *
+ * @param ns		namespace
+ * @param fn		function to register
+ */
+#define EXPORT_FUNCTION_FOR_TESTS(ns, fn) \
+static void testable_function_register_##fn() __attribute__ ((constructor(2000))); \
+static void testable_function_register_##fn() \
+{ \
+	testable_function_register(#ns "/" #fn, fn); \
+} \
+static void testable_function_unregister_##fn() __attribute__ ((destructor(2000))); \
+static void testable_function_unregister_##fn() \
+{ \
+	testable_function_register(#ns "/" #fn, NULL); \
+}
+
+/**
+ * Import a registered function so that it can be called from tests.
+ *
+ * @note If the imported function is static (or no conflicting header files
+ * are included) ret can be prefixed with static to declare the function static.
+ *
+ * @note We allocate an arbitrary amount of stack space, hopefully enough for
+ * all arguments.
+ *
+ * @param ns		namespace of the function
+ * @param name		name of the function
+ * @param ret		return type of the function
+ * @param ...		arguments of the function
+ */
+#define IMPORT_FUNCTION_FOR_TESTS(ns, name, ret, ...) \
+ret name(__VA_ARGS__) \
+{ \
+	void (*fn)() = NULL; \
+	if (testable_functions) \
+	{ \
+		fn = testable_functions->get(testable_functions, #ns "/" #name); \
+	} \
+	if (fn) \
+	{ \
+		void *args = __builtin_apply_args(); \
+		__builtin_return(__builtin_apply(fn, args, 16*sizeof(void*))); \
+	} \
+	test_fail_msg(__FILE__, __LINE__, "function " #name " (" #ns ") not found"); \
+	__builtin_return(NULL); \
+}
+
+#endif /** TEST_H_ @}*/