[CMAKE] Allow running tests from the main source build

When no alternative toolchain is provided, we explicitely include
the src/tests directory, so the check target (which builds and runs
tests) is available from a main source build without having to
build specifically the src/tests directory

CMakeLists.txt

@@ -1,17 +1,23 @@
 cmake_minimum_required(VERSION 3.17)
 
-set(TOOLCHAIN_OPTIONS "arm-none-eabi")
+set(TOOLCHAIN_OPTIONS none arm-none-eabi)
 set(TOOLCHAIN "arm-none-eabi" CACHE STRING "Toolchain to use. Available: ${TOOLCHAIN_OPTIONS}")
 set_property(CACHE TOOLCHAIN PROPERTY STRINGS ${TOOLCHAIN_OPTIONS})
+if("" STREQUAL TOOLCHAIN)
+    set(TOOLCHAIN none)
+endif()
 if (NOT ${TOOLCHAIN} IN_LIST TOOLCHAIN_OPTIONS)
-    message(FATAL_ERROR "Invalid toolchain ${TOOLCHAIN}")
+    message(FATAL_ERROR "Invalid toolchain ${TOOLCHAIN}. Valid options are: ${TOOLCHAIN_OPTIONS}")
 endif()
 
-set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/cmake/${TOOLCHAIN}.cmake")
+if(TOOLCHAIN STREQUAL none)
+    add_subdirectory(src/test)
+else()
+    set(CMAKE_TOOLCHAIN_FILE "${CMAKE_CURRENT_SOURCE_DIR}/cmake/${TOOLCHAIN}.cmake")
+endif()
 
 if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo")
     set(IS_RELEASE_BUILD ON)
-    set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON)
 endif()
 
 project(INAV VERSION 2.5.0)

cmake/main.cmake

@@ -55,6 +55,11 @@ function(setup_executable exe name)
     set_target_properties(${exe} PROPERTIES
         RUNTIME_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/bin"
     )
+    if(IS_RELEASE_BUILD)
+        set_target_properties(${exe} PROPERTIES
+            INTERPROCEDURAL_OPTIMIZATION ON
+        )
+    endif()
 endfunction()
 
 function(setup_firmware_target exe name)

cmake/stm32.cmake

@@ -1,4 +1,3 @@
-include(arm-none-eabi)
 include(stm32-bootloader)
 include(stm32f3)
 include(stm32f4)
@@ -267,6 +266,9 @@ function(add_stm32_executable)
 endfunction()
 
 function(target_stm32)
+    if(NOT arm-none-eabi STREQUAL TOOLCHAIN)
+        return()
+    endif()
     # Parse keyword arguments
     cmake_parse_arguments(
         args

src/test/CMakeLists.txt

@@ -13,5 +13,4 @@ include(cmake/gtest.cmake)
 
 enable_testing()
 include(GoogleTest)
-#add_subdirectory(googletest)
 add_subdirectory(unit)