The purpose of this test is to ensure that C++ constructors are executed properly during the startup of RIOT. This requires that the port calls constructors somewhere during C-library initialization. On newlib ports this is done by _libc_init_array(), other ports may need to manually iterate through the list of initializer functions (usually .initarray), and call each one in order.

There are three tests:

• Global constructor
• Static constructor
• Local constructor

The global constructor test checks to see if the constructor of a global object has been run during the boot process. The static constructor test does the same, but for static object inside a function. The local constructor test checks that a locally created object does have its constructor run. The local constructor test will only fail if there is a significant problem with the C++ tool chain, since it does not rely on any external C++ support code.