Add ntest to build

This adds the ntest systemcmd using ntestlib to the build. This is the
equivalent of gtest testing on Posix for NuttX.

This works as follows:
1. At cmake configure time all tests are added to global cmake lists.
2. Then when ntest is configured (last), the collected test sources and
   dependencies are added to the ntest build.

When compiling for NuttX we need to include ntestlib.h, when building
for Posix we need to include gtest.h (see px4_unittesting.h).

CMakeLists.txt

@@ -425,9 +425,10 @@ endif()
 # enable test filtering to run only specific tests with the ctest -R regex functionality
 set(TESTFILTER "" CACHE STRING "Filter string for ctest to selectively only run specific tests (ctest -R)")
 
-# if testing is enabled download and configure gtest
 list(APPEND CMAKE_MODULE_PATH ${PX4_SOURCE_DIR}/cmake/gtest/)
 include(px4_add_gtest)
+
+# if testing is enabled download and configure gtest
 if(BUILD_TESTING)
 	include(gtest)
 endif()

boards/px4/fmu-v2/test.cmake

@@ -107,6 +107,7 @@ px4_add_board(
 		#topic_listener
 		tune_control
 		ver
+		ntest # needs to be last
 
 	EXAMPLES
 		#bottle_drop # OBC challenge

boards/px4/fmu-v3/default.cmake

@@ -114,6 +114,7 @@ px4_add_board(
 		tune_control
 		usb_connected
 		ver
+		ntest # needs to be last
 
 	EXAMPLES
 		bottle_drop # OBC challenge

boards/px4/fmu-v4/default.cmake

@@ -98,6 +98,7 @@ px4_add_board(
 		tune_control
 		usb_connected
 		ver
+		ntest # needs to be last
 
 	EXAMPLES
 		bottle_drop # OBC challenge

boards/px4/fmu-v5/default.cmake

@@ -114,6 +114,7 @@ px4_add_board(
 		tune_control
 		usb_connected
 		ver
+		ntest # needs to be last
 
 	EXAMPLES
 		bottle_drop # OBC challenge

cmake/gtest/px4_add_gtest.cmake

@@ -40,31 +40,46 @@ include(px4_base)
 #	Adds a googletest unit test to the test_results target.
 #
 function(px4_add_gtest)
-	# skip if unit testing is not configured
-	if(BUILD_TESTING)
-		# parse source file and library dependencies from arguments
-		px4_parse_function_args(
-			NAME px4_add_gtest
-			ONE_VALUE SRC
-			MULTI_VALUE LINKLIBS
-			REQUIRED SRC
-			ARGN ${ARGN})
+	# parse source file and library dependencies from arguments
+	px4_parse_function_args(
+		NAME px4_add_gtest
+		ONE_VALUE SRC
+		MULTI_VALUE LINKLIBS
+		REQUIRED SRC
+		ARGN ${ARGN})
 
-		# infer test name from source filname
-		get_filename_component(TESTNAME ${SRC} NAME_WE)
-		string(REPLACE Test "" TESTNAME ${TESTNAME})
-		set(TESTNAME unit-${TESTNAME})
+	# infer test name from source filname
+	get_filename_component(TESTNAME ${SRC} NAME_WE)
+	string(REPLACE Test "" TESTNAME ${TESTNAME})
+
+	if (${PX4_PLATFORM} STREQUAL "nuttx")
+		get_property(sources GLOBAL PROPERTY ntest_test_sources)
+		list(APPEND sources ${CMAKE_CURRENT_SOURCE_DIR}/${SRC})
+		set_property(GLOBAL PROPERTY ntest_test_sources ${sources})
+
+		get_property(dependencies GLOBAL PROPERTY ntest_test_dependencies)
 
+		foreach(dep ${dependencies})
+			list(APPEND dependencies ${dep})
+		endforeach()
+		set_property(GLOBAL PROPERTY ntest_test_dependencies ${dependencies})
+
+		# Note: If the systemcmd ntest is not build, these properties won't be
+		#       taken into account.
+
+	else()
+		set(TESTNAME unit-${TESTNAME})
 		# build a binary for the unit test
 		add_executable(${TESTNAME} EXCLUDE_FROM_ALL ${SRC})
 
+		# attach it to the unit test target
+		add_dependencies(test_results ${TESTNAME})
+
 		# link the libary to test and gtest
 		target_link_libraries(${TESTNAME} ${LINKLIBS} gtest_main)
 
 		# add the test to the ctest plan
 		add_test(NAME ${TESTNAME} COMMAND ${TESTNAME})
 
-		# attach it to the unit test target
-		add_dependencies(test_results ${TESTNAME})
 	endif()
 endfunction()

platforms/nuttx/CMakeLists.txt

@@ -108,7 +108,15 @@ target_link_libraries(px4 PRIVATE
 	gcc
 	)
 
-target_link_libraries(px4 PRIVATE ${module_libraries})
+foreach(module ${module_libraries})
+	# Hack for ntest to avoid the linker from stripping the static global test registrars.
+	if ("${module}" STREQUAL "ntest")
+		target_link_libraries(px4 PRIVATE -Wl,--whole-archive ${module} -Wl,--no-whole-archive)
+		message(STATUS "Adding ntest")
+	else()
+		target_link_libraries(px4 PRIVATE ${module})
+	endif()
+endforeach()
 
 if (config_romfs_root)
 	add_subdirectory(${PX4_SOURCE_DIR}/ROMFS ${PX4_BINARY_DIR}/ROMFS)

platforms/posix/src/lockstep_scheduler/test/src/lockstep_scheduler_test.cpp

@@ -1,5 +1,5 @@
 #include <lockstep_scheduler/lockstep_scheduler.h>
-#include <gtest/gtest.h>
+#include <px4_unittesting.h>
 #include <thread>
 #include <atomic>
 #include <random>

src/lib/hysteresis/HysteresisTest.cpp

@@ -36,7 +36,7 @@
  * Tests for system timing hysteresis.
  */
 
-#include <gtest/gtest.h>
+#include <px4_unittesting.h>
 
 #include "hysteresis.h"
 

src/modules/mc_att_control/AttitudeControl/AttitudeControlTest.cpp

@@ -31,8 +31,9 @@
  *
  ****************************************************************************/
 
-#include <gtest/gtest.h>
-#include <AttitudeControl.hpp>
+#include <px4_unittesting.h>
+
+#include "AttitudeControl.hpp"
 
 using namespace matrix;
 

src/modules/mc_pos_control/Takeoff/TakeoffTest.cpp

@@ -31,8 +31,9 @@
  *
  ****************************************************************************/
 
-#include <gtest/gtest.h>
-#include <Takeoff.hpp>
+#include <px4_unittesting.h>
+
+#include "Takeoff.hpp"
 
 TEST(TakeoffTest, Initialization)
 {

src/platforms/px4_unittesting.h

@@ -0,0 +1,47 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2019 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/**
+ * @file px4_unittesting.h
+ *
+ * File to include the appropriate header files for unit testing on the
+ * respective platform.
+ */
+
+#pragma once
+
+#ifdef __PX4_NUTTX
+#include <lib/ntestlib/ntestlib.h>
+#else
+#include <gtest/gtest.h>
+#endif