/**
 * @page article_saveram Saving RAM by declaring thread functions "noreturn"
 * @{
 * One of the problems, when writing embedded multi-threaded applications,
 * is that the thread functions do save the registers in the function
 * entry code even if the system does not require it, exiting such
 * a function would terminate the thread so there is no need to preserve
 * the register values. This can waste tens of bytes for each thread.<br>
 * Consider the following code: 
 * @code
#include <ch.h>

static WORKING_AREA(waMyThread, 64);

static t_msg MyThread(void *arg) {
  while (!chThdShoudTerminate()) {
    /* Do thread inner work */
  }
  return 1;
}

main() {
  chSysInit();
  ...
  chThdCreateStatic(waMyThread, sizeof(waMyThread), NORMALPRIO, MyThread, NULL);
  ...
}
 * @endcode
 * The resulting ASM code for the thread function would be something like this:
 * @code
MyThread:
        stmfd   sp!, {r4, r5, r6, lr}
        ...
        ldmfd   sp!, {r4, r5, r6, pc}
 * @endcode
 * Being that function a thread there is no need to save those registers, in
 * embedded applications often the RAM is a scarce resource. That space can be
 * saved by modifying the code as follow, using some advanced GCC extensions: 
 * @code
#include <ch.h>

static WORKING_AREA(waMyThread, 64);

__attribute__((noreturn))
static void MyThread(void *arg) {
  while (!chThdShoudTerminate()) {
    /* Do thread inner work */
  }
  chThdExit(1);
}

main() {
  chSysInit();
  ...
  chThdCreateStatic(waMyThread, sizeof(waMyThread), NORMALPRIO, MyThread, NULL);
  ...
}
 * @endcode
 * This will make GCC believe that the function cannot return and there is no
 * need to save registers. The code will be a bit less readable and less
 * portable on other compilers however.
 */
/** @} */