core: thread_measure_stack_free() is only useful for DEVELHELP

core/include/thread.h

@@ -130,6 +130,7 @@ int thread_wakeup(kernel_pid_t pid);
  */
 kernel_pid_t thread_getpid(void);
 
+#ifdef DEVELHELP
 /**
  * @brief Measures the stack usage of a stack
  *
@@ -140,6 +141,7 @@ kernel_pid_t thread_getpid(void);
  * @return          the amount of unused space of the thread's stack
  */
 int thread_measure_stack_free(char *stack);
+#endif
 
 /* @} */
 #endif /* __THREAD_H */

core/thread.c

@@ -92,6 +92,7 @@ int thread_wakeup(kernel_pid_t pid)
     }
 }
 
+#ifdef DEVELHELP
 int thread_measure_stack_free(char *stack)
 {
     unsigned int *stackp = (unsigned int *)stack;
@@ -105,6 +106,7 @@ int thread_measure_stack_free(char *stack)
     int space_free = (unsigned int)stackp - (unsigned int)stack;
     return space_free;
 }
+#endif
 
 kernel_pid_t thread_create(char *stack, int stacksize, char priority, int flags, void *(*function)(void *arg), void *arg, const char *name)
 {
@@ -133,6 +135,7 @@ kernel_pid_t thread_create(char *stack, int stacksize, char priority, int flags,
         return -EINVAL;
     }
 
+#ifdef DEVELHELP
     if (flags & CREATE_STACKTEST) {
         /* assign each int of the stack the value of it's address */
         unsigned int *stackmax = (unsigned int *)((char *)stack + stacksize);
@@ -147,6 +150,7 @@ kernel_pid_t thread_create(char *stack, int stacksize, char priority, int flags,
         /* create stack guard */
         *stack = (unsigned int)stack;
     }
+#endif
 
     if (!inISR()) {
         dINT();