Check all default paths existence before setting them #232
Description
If no configuration is provided via environment/argument/upper CMakeList.txt, default paths will be set. However, it is not checked whether these paths/directories actually exist. It would be a good idea to do this everywhere this is done.
Example which might be merged in FindFreeRTOS.cmake soon (#227) :
if(NOT FREERTOS_PATH)
set(FREERTOS_PATH $ENV{FREERTOS_PATH} CACHE PATH "Path to FreeRTOS")
endif()
if(NOT FREERTOS_PATH)
set(DEFAULT_FREERTOS_PATH "/opt/FreeRTOS")
if(EXISTS ${DEFAULT_FREERTOS_PATH})
set(FREERTOS_PATH ${DEFAULT_FREERTOS_PATH} CACHE PATH "Path to FreeRTOS")
message(STATUS "No FREERTOS_PATH specified using default: ${DEFAULT_FREERTOS_PATH}")
else()
message(STATUS
"No FreeRTOS folder found at default location ${DEFAULT_FREERTOS_PATH}. "
"Leaving empty
)
endif()
endif()