System Workbench for STM32

Another way you can force the inclusion of the infinite while() loop (with optimization on) would be to declare the i variable volatile, like this:

volatile uint32_t i;
while (1)
{
i++;
}

Doing this is also useful when you want to create a software delay and don't care about accuracy, like this:

volatile uint32_t i;
for (i = 100000; i > 0; i--) ;

As for use of compiler optimization, I normally set the optimization level to "optimize for debug (-Og)" for the debug build of my projects, and use higher level optimization, normally "optimize for size (-Os)" for the release build.