turn on warnings and errors (#280)

examples/platforms/cc2538/logging.c

@@ -36,5 +36,8 @@
 
 void otPlatLog(otLogLevel aLogLevel, otLogRegion aLogRegion, const char *aFormat, ...)
 {
+    (void)aLogLevel;
+    (void)aLogRegion;
+    (void)aFormat;
 }
 

examples/platforms/cc2538/platform.c

@@ -41,6 +41,9 @@ void PlatformInit(int argc, char *argv[])
     cc2538RadioInit();
     cc2538RandomInit();
     otPlatUartEnable();
+
+    (void)argc;
+    (void)argv;
 }
 
 void PlatformProcessDrivers(void)

examples/platforms/cc2538/startup-gcc.c

@@ -47,7 +47,7 @@ extern uint8_t _einit_array;
 __extension__ typedef int __guard __attribute__((mode(__DI__)));
 int __cxa_guard_acquire(__guard *g) { return !*(char *)(g); }
 void __cxa_guard_release(__guard *g) { *(char *)g = 1; }
-void __cxa_guard_abort(__guard *g) {}
+void __cxa_guard_abort(__guard *g) { (void)g; }
 void __cxa_pure_virtual(void) { while (1); }
 
 void IntDefaultHandler(void);