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/Android.mk

@@ -36,7 +36,7 @@ selectors/traffic_selector.c threading/thread.c threading/thread_value.c \
 threading/mutex.c threading/semaphore.c threading/rwlock.c threading/spinlock.c \
 utils/utils.c utils/chunk.c utils/debug.c utils/enum.c utils/identification.c \
 utils/lexparser.c utils/optionsfrom.c utils/capabilities.c utils/backtrace.c \
-utils/printf_hook/printf_hook_builtin.c utils/settings.c
+utils/printf_hook/printf_hook_builtin.c utils/settings.c utils/test.c
 
 # adding the plugin source files
 

src/libstrongswan/Makefile.am

@@ -34,7 +34,7 @@ selectors/traffic_selector.c threading/thread.c threading/thread_value.c \
 threading/mutex.c threading/semaphore.c threading/rwlock.c threading/spinlock.c \
 utils/utils.c utils/chunk.c utils/debug.c utils/enum.c utils/identification.c \
 utils/lexparser.c utils/optionsfrom.c utils/capabilities.c utils/backtrace.c \
-utils/settings.c
+utils/settings.c utils/test.c
 
 if USE_DEV_HEADERS
 strongswan_includedir = ${dev_headers}
@@ -82,7 +82,7 @@ utils/utils.h utils/chunk.h utils/debug.h utils/enum.h utils/identification.h \
 utils/lexparser.h utils/optionsfrom.h utils/capabilities.h utils/backtrace.h \
 utils/leak_detective.h utils/printf_hook/printf_hook.h \
 utils/printf_hook/printf_hook_vstr.h utils/printf_hook/printf_hook_builtin.h \
-utils/settings.h utils/integrity_checker.h
+utils/settings.h utils/test.h utils/integrity_checker.h
 endif
 
 library.lo :	$(top_builddir)/config.status

src/libstrongswan/tests/test_runner.c

@@ -20,6 +20,7 @@
 #include <library.h>
 #include <plugins/plugin_feature.h>
 #include <collections/array.h>
+#include <utils/test.h>
 
 #include <dirent.h>
 #include <unistd.h>
@@ -30,6 +31,30 @@
  */
 #define TTY(color) tty_escape_get(2, TTY_FG_##color)
 
+/**
+ * Initialize the lookup table for testable functions (defined in libstrongswan)
+ */
+static void testable_functions_create() __attribute__ ((constructor(1000)));
+static void testable_functions_create()
+{
+	testable_functions = hashtable_create(hashtable_hash_str,
+										  hashtable_equals_str, 8);
+}
+
+/**
+ * Destroy the lookup table for testable functions
+ */
+static void testable_functions_destroy() __attribute__ ((destructor(1000)));
+static void testable_functions_destroy()
+{
+	testable_functions->destroy(testable_functions);
+	/* if leak detective is enabled plugins are not actually unloaded, which
+	 * means their destructor is called AFTER this one when the process
+	 * terminates, even though the priority says differently, make sure this
+	 * does not crash */
+	testable_functions = NULL;
+}
+
 /**
  * Load all available test suites
  */

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_ @}*/