Silence additional compiler warnings about lack of return value

src/fd-net-device/helper/emu-fd-net-device-helper.cc

@@ -430,6 +430,8 @@ EmuFdNetDeviceHelper::CreateFileDescriptor (void) const
         }
       NS_FATAL_ERROR ("Did not get the raw socket from the socket creator");
     }
+  NS_FATAL_ERROR ("Should be unreachable");
+  return 0; // Silence compiler warning about lack of return value
 }
 
 } // namespace ns3

src/fd-net-device/helper/tap-fd-net-device-helper.cc

@@ -399,7 +399,8 @@ TapFdNetDeviceHelper::CreateFileDescriptor (void) const
         }
       NS_FATAL_ERROR ("Did not get the raw socket from the socket creator");
     }
-
+  NS_FATAL_ERROR ("Should be unreachable");
+  return 0; // Silence compiler warning about lack of return value
 }
 
 } // namespace ns3

src/internet/model/tcp-tx-buffer.cc

@@ -580,6 +580,7 @@ TcpTxBuffer::GetPacketFromList (PacketList &list, const SequenceNumber32 &listSt
     }
 
   NS_FATAL_ERROR ("This point is not reachable");
+  return nullptr; // Silence compiler warning about lack of return value
 }
 
 void

src/lte/helper/lte-stats-calculator.cc

@@ -158,6 +158,7 @@ LteStatsCalculator::FindImsiFromEnbRlcPath (std::string path)
     {
       NS_FATAL_ERROR ("Lookup " << ueMapPath << " got no matches");
     }
+  return 0; // Silence compiler warning about lack of return value
 }
 
 uint64_t
@@ -205,6 +206,7 @@ LteStatsCalculator::FindImsiFromLteNetDevice (std::string path)
     {
       NS_FATAL_ERROR ("Lookup " << path << " got no matches");
     }
+  return 0; // Silence compiler warning about lack of return value
 }
 
 uint16_t
@@ -227,6 +229,7 @@ LteStatsCalculator::FindCellIdFromEnbRlcPath (std::string path)
     {
       NS_FATAL_ERROR ("Lookup " << enbNetDevicePath << " got no matches");
     }
+  return 0; // Silence compiler warning about lack of return value
 }
 
 uint64_t

src/wifi/model/phy-entity.cc

@@ -171,6 +171,7 @@ PhyEntity::GetNextField (WifiPpduField currentField, WifiPreamble preamble) cons
     {
       NS_FATAL_ERROR ("Unsupported preamble " << preamble << " for the provided PPDU formats");
     }
+  return WifiPpduField::WIFI_PPDU_FIELD_PREAMBLE; // Silence compiler warning
 }
 
 Time

src/wifi/model/qos-utils.cc

@@ -246,6 +246,7 @@ GetTid (Ptr<const Packet> packet, const WifiMacHeader hdr)
     {
       NS_FATAL_ERROR ("Packet has no Traffic ID");
     }
+  return 0; // Silence compiler warning about lack of return value
 }
 
 uint8_t