Fix all warnings for native and qemu-i386

Missing returns, unused variables (only used for debugging), empty
translation units, missing function prototypes, and GNU extensions.

cpu/native/include/native_internal.h

@@ -65,6 +65,7 @@ extern int (*real_fork)(void);
 extern int (*real_dup2)(int, int);
 extern int (*real_unlink)(const char *);
 extern int (*real_execve)(const char *, char *const[], char *const[]);
+extern int (*real_pause)(void);
 
 /**
  * data structures

cpu/native/lpm_cpu.c

@@ -80,7 +80,7 @@ void _native_lpm_sleep(void)
     /* otherwise select was interrupted because of a signal, continue below */
 #else
     _native_in_syscall++; // no switching here
-    pause();
+    real_pause();
     _native_in_syscall--;
 #endif
 

cpu/native/startup.c

@@ -205,6 +205,7 @@ __attribute__((constructor)) static void startup(int argc, char **argv)
     *(void **)(&real_dup2) = dlsym(RTLD_NEXT, "dup2");
     *(void **)(&real_unlink) = dlsym(RTLD_NEXT, "unlink");
     *(void **)(&real_execve) = dlsym(RTLD_NEXT, "execve");
+    *(void **)(&real_pause) = dlsym(RTLD_NEXT, "pause");
 
     _native_argv = argv;
     _progname = argv[0];

cpu/native/syscalls.c

@@ -60,6 +60,7 @@ int (*real_fork)(void);
 int (*real_dup2)(int, int);
 int (*real_unlink)(const char *);
 int (*real_execve)(const char *, char *const[], char *const[]);
+int (*real_pause)(void);
 
 void _native_syscall_enter(void)
 {

examples/rpl_udp/helper.c

@@ -98,6 +98,8 @@ void rpl_udp_monitor(void)
             if (ipv6_buf->nextheader == IPV6_PROTO_NUM_ICMPV6) {
                 DEBUG("\t ICMP type: %02X ", icmp_type);
                 DEBUG("\t ICMP code: %02X ", icmp_code);
+                (void) icmp_type;
+                (void) icmp_code;
             }
 
             printf("\n");

sys/net/ccn_lite/ccnl-ext-frag.c

@@ -707,5 +707,8 @@ Bail:
     return -1;
 }
 
-#endif // USE_FRAG
-// eof
+#else // USE_FRAG
+
+static int dummy __attribute__((unused));
+
+#endif

sys/net/include/destiny/types.h

@@ -55,9 +55,9 @@ typedef struct __attribute__((packed)) {
     uint16_t    dst_port;               ///< destination port
     uint32_t    seq_nr;                 ///< sequence number
     uint32_t    ack_nr;                 ///< acknowledgement number
-    uint8_t     flag_ns         :1;     ///< ECN-nonce concealment protection (since RFC 3540).
-    uint8_t     reserved        :3;     ///< for future use - set to zero
-    uint8_t     data_offset     :4;
+    unsigned    flag_ns         :1;     ///< ECN-nonce concealment protection (since RFC 3540).
+    unsigned    reserved        :3;     ///< for future use - set to zero
+    unsigned    data_offset     :4;
     uint8_t     reserved_flags;         ///< TODO: break this down into another bitfield: flag_fin, flag_syn, etc
     uint16_t    window;                 ///< receiver window
     /**

sys/net/network_layer/sixlowpan/icmp.c

@@ -1144,6 +1144,8 @@ void recv_nbr_sol(void)
                             }
                         }
                     }
+
+                    (void) aro_state;
                 }
 
                 break;

sys/net/routing/rpl/rpl.c

@@ -985,6 +985,7 @@ void rpl_send(ipv6_addr_t *destination, uint8_t *payload, uint16_t p_len, uint8_
         ipv6_send_packet(ipv6_send_buf);
     }
 
+    (void) packet_length;
 }
 
 ipv6_addr_t *rpl_get_next_hop(ipv6_addr_t *addr)

tests/test_posix_semaphore/main.c

@@ -160,4 +160,5 @@ int main(void)
     puts("#########################");
     test2();
     puts("#########################");
+    return 0;
 }

tests/test_posix_sleep/main.c

@@ -40,4 +40,5 @@ int main(void)
     }
 
     puts("done");
+    return 0;
 }

tests/test_pthread_barrier/main.c

@@ -43,7 +43,7 @@ static void *run(void *id_)
         pthread_barrier_wait(&barrier);
 
         uint32_t timeout_us = genrand_uint32() % 2500000;
-        printf("Child %i sleeps for % 8" PRIu32 " µs.\n", id, timeout_us);
+        printf("Child %i sleeps for %8" PRIu32 " µs.\n", id, timeout_us);
         vtimer_usleep(timeout_us);
     }
 

tests/test_thread_basic/main.c

@@ -36,4 +36,5 @@ int main(void)
 {
     (void) thread_create(t2_stack, STACK_SIZE, PRIORITY_MAIN - 1, CREATE_WOUT_YIELD | CREATE_STACKTEST, second_thread, "nr2");
     puts("first thread\n");
+    return 0;
 }

tests/test_thread_exit/main.c

@@ -86,4 +86,5 @@ int main(void)
     }
 
     puts("main: exiting");
+    return 0;
 }

tests/test_thread_msg/main.c

@@ -82,4 +82,5 @@ int main(void)
     p3 = thread_create(t3_stack, KERNEL_CONF_STACKSIZE_PRINTF, PRIORITY_MAIN - 1,
                        CREATE_WOUT_YIELD | CREATE_STACKTEST, thread3, "nr3");
     puts("THREADS CREATED\n");
+    return 0;
 }

tests/test_thread_msg_block_w_queue/main.c

@@ -62,4 +62,5 @@ int main(void)
     msg_receive(&msg);
 
     printf("MAIN THREAD %u ALIVE!\n", p_main);
+    return 0;
 }

tests/test_thread_msg_block_wo_queue/main.c

@@ -59,4 +59,5 @@ int main(void)
     msg_receive(&msg);
 
     printf("MAIN THREAD %u ALIVE!\n", p_main);
+    return 0;
 }