18 files changed, 27 insertions, 56 deletions

diff --git a/src/BlockEntities/NoteEntity.cpp b/src/BlockEntities/NoteEntity.cpp
index 3e9958892..419d084b2 100644
--- a/src/BlockEntities/NoteEntity.cpp
+++ b/src/BlockEntities/NoteEntity.cpp
@@ -318,6 +318,5 @@ float cNoteEntity::PitchFromNote(unsigned char a_Pitch)
 		case 23: return 1.887748625363387f;
 		case 24: return 2.0f;
 	}
-
 	UNREACHABLE("Converted unknown pitch value");
 }
diff --git a/src/Blocks/BlockButton.h b/src/Blocks/BlockButton.h
index 062bd5057..985c1fff9 100644
--- a/src/Blocks/BlockButton.h
+++ b/src/Blocks/BlockButton.h
@@ -132,8 +132,7 @@ private:
 			case BLOCK_FACE_YM: return 0x0;
 			case BLOCK_FACE_NONE:
 			{
-				ASSERT(!"Unhandled block face!");
-				return 0x0;
+				break;
 			}
 		}
 		UNREACHABLE("Unsupported block face");
@@ -265,10 +264,9 @@ private:
 			case BLOCK_FACE_YP: return { 0.5, 0, 0.5 };
 			case BLOCK_FACE_NONE:
 			{
-				ASSERT(!"Unhandled block face!");
-				return { 0, 0, 0 };
+				break;
 			}
 		}
-		UNREACHABLE(!"Unhandled block face!");
+		UNREACHABLE("Unhandled block face!");
 	}
 } ;
diff --git a/src/Blocks/BlockCocoaPod.h b/src/Blocks/BlockCocoaPod.h
index d78164ea6..caff5c028 100644
--- a/src/Blocks/BlockCocoaPod.h
+++ b/src/Blocks/BlockCocoaPod.h
@@ -28,8 +28,7 @@ public:
 			case BLOCK_FACE_YM:
 			case BLOCK_FACE_YP:
 			{
-				ASSERT(!"Unknown face");
-				return 0;
+				break;
 			}
 		}
 		UNREACHABLE("Unsupported block face");
diff --git a/src/Blocks/BlockHandler.cpp b/src/Blocks/BlockHandler.cpp
index 0e1672ce8..71169ea7f 100644
--- a/src/Blocks/BlockHandler.cpp
+++ b/src/Blocks/BlockHandler.cpp
@@ -936,6 +936,5 @@ const cBlockHandler & cBlockHandler::For(BLOCKTYPE a_BlockType)
 		case E_BLOCK_NUMBER_OF_TYPES:
 		case E_BLOCK_UNFINISHED: return BlockAirHandler;
 	}
-
 	UNREACHABLE("Getting handler for unexpected block type");
 }
diff --git a/src/Blocks/BlockSideways.h b/src/Blocks/BlockSideways.h
index a8eb52fc6..a6e035601 100644
--- a/src/Blocks/BlockSideways.h
+++ b/src/Blocks/BlockSideways.h
@@ -74,8 +74,7 @@ private:
 
 			case BLOCK_FACE_NONE:
 			{
-				ASSERT(!"Unhandled block face!");
-				return a_Meta | 0xC;  // No idea, give a special meta
+				break;
 			}
 		}
 		UNREACHABLE("Unsupported block face");
diff --git a/src/Blocks/BlockTripwireHook.h b/src/Blocks/BlockTripwireHook.h
index 0d46da437..0d58bb084 100644
--- a/src/Blocks/BlockTripwireHook.h
+++ b/src/Blocks/BlockTripwireHook.h
@@ -70,7 +70,6 @@ private:
 				return false;
 			}
 		}
-
 		UNREACHABLE("Unsupported block face");
 	}
 
diff --git a/src/Defines.cpp b/src/Defines.cpp
index 7e4274bd5..4adbc1c5c 100644
--- a/src/Defines.cpp
+++ b/src/Defines.cpp
@@ -41,7 +41,6 @@ const char * ClickActionToString(int a_ClickAction)
 		case caRightPaintEnd:                return "caRightPaintEnd";
 		case caMiddlePaintEnd:               return "caMiddlePaintEnd";
 		case caDblClick:                     return "caDblClick";
-
 		case caUnknown:                      return "caUnknown";
 	}
 	UNREACHABLE("Unknown click action");
diff --git a/src/Generating/StructGen.cpp b/src/Generating/StructGen.cpp
index d9620b19d..9fa413e2d 100644
--- a/src/Generating/StructGen.cpp
+++ b/src/Generating/StructGen.cpp
@@ -287,8 +287,7 @@ double cStructGenTrees::GetNumTrees(
 			case biVariant:
 			case biNumVariantBiomes:
 			{
-				ASSERT(!"Invalid biome in cStructGenTrees::GetNumTrees");
-				return 0.0;
+				break;
 			}
 		}
 		UNREACHABLE("Unsupported biome");
diff --git a/src/Globals.h b/src/Globals.h
index c081c5998..bc868b637 100644
--- a/src/Globals.h
+++ b/src/Globals.h
@@ -35,11 +35,15 @@
 		// The CRT has a definition for this operator new that stores the debugging info for leak-finding later.
 	#endif
 
+	#define UNREACHABLE_INTRINSIC __assume(false)
+
 #elif defined(__GNUC__)
 
 	// TODO: Can GCC explicitly mark classes as abstract (no instances can be created)?
 	#define abstract
 
+	#define UNREACHABLE_INTRINSIC __builtin_unreachable()
+
 #else
 
 	#error "You are using an unsupported compiler, you might need to #define some stuff here for your compiler"
@@ -271,8 +275,12 @@ template class SizeChecker<UInt8, 1>;
 
 #endif  // else TEST_GLOBALS
 
-/** Use to mark code that should be impossible to reach. */
-#define UNREACHABLE(x) do { FLOGERROR("Hit unreachable code: {0}, file {1}, line {2}", #x, __FILE__, __LINE__); std::abort(); } while (false)
+// Use to mark code that should be impossible to reach.
+#ifdef NDEBUG
+	#define UNREACHABLE(x) UNREACHABLE_INTRINSIC
+#else
+	#define UNREACHABLE(x) ( FLOGERROR("Hit unreachable code: {0}, file {1}, line {2}", #x, __FILE__, __LINE__), std::abort(), 0)
+#endif
 
 
 
diff --git a/src/MobCensus.cpp b/src/MobCensus.cpp
index 1069a964e..8f5fdde75 100644
--- a/src/MobCensus.cpp
+++ b/src/MobCensus.cpp
@@ -41,8 +41,7 @@ int cMobCensus::GetCapMultiplier(cMonster::eFamily a_MobFamily)
 		case cMonster::mfNoSpawn:
 		case cMonster::mfUnhandled:
 		{
-			ASSERT(!"Unhandled mob family");
-			return -1;
+			break;
 		}
 	}
 	UNREACHABLE("Unsupported mob family");
diff --git a/src/Protocol/ChunkDataSerializer.cpp b/src/Protocol/ChunkDataSerializer.cpp
index 2c45eea58..ec7fa6648 100644
--- a/src/Protocol/ChunkDataSerializer.cpp
+++ b/src/Protocol/ChunkDataSerializer.cpp
@@ -118,7 +118,6 @@ void cChunkDataSerializer::SendToClients(const int a_ChunkX, const int a_ChunkZ,
 				continue;
 			}
 		}
-
 		UNREACHABLE("Unknown chunk data serialization version");
 	}
 
diff --git a/src/Protocol/Protocol_1_10.cpp b/src/Protocol/Protocol_1_10.cpp
index b3a3205d5..89bc3f010 100644
--- a/src/Protocol/Protocol_1_10.cpp
+++ b/src/Protocol/Protocol_1_10.cpp
@@ -1053,7 +1053,7 @@ void cProtocol_1_10_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 		case mtZombieHorse:
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_10::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_10::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -1072,10 +1072,7 @@ void cProtocol_1_10_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 			// Entities without additional metadata
 			break;
 		}
-		case mtInvalidType:
-		{
-			break;
-		}
+
 		default: UNREACHABLE("cProtocol_1_10::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
diff --git a/src/Protocol/Protocol_1_11.cpp b/src/Protocol/Protocol_1_11.cpp
index ff0c34223..c8ba78e62 100644
--- a/src/Protocol/Protocol_1_11.cpp
+++ b/src/Protocol/Protocol_1_11.cpp
@@ -1241,7 +1241,7 @@ void cProtocol_1_11_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 		case mtVindicator:
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_11::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_11::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -1260,10 +1260,7 @@ void cProtocol_1_11_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_
 			// Mobs without additional metadata
 			break;
 		}
-		case mtInvalidType:
-		{
-			break;
-		}
+
 		default: UNREACHABLE("cProtocol_1_11::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
diff --git a/src/Protocol/Protocol_1_12.cpp b/src/Protocol/Protocol_1_12.cpp
index e4ce9a942..81f81dc1c 100644
--- a/src/Protocol/Protocol_1_12.cpp
+++ b/src/Protocol/Protocol_1_12.cpp
@@ -957,7 +957,7 @@ void cProtocol_1_12::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_Mo
 		case mtVindicator:
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_12::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_12::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -970,10 +970,6 @@ void cProtocol_1_12::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_Mo
 			break;
 		}
 
-		case mtInvalidType:
-		{
-			break;
-		}
 		default: UNREACHABLE("cProtocol_1_12::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
diff --git a/src/Protocol/Protocol_1_13.cpp b/src/Protocol/Protocol_1_13.cpp
index dbfd51d59..afb0a9cc9 100644
--- a/src/Protocol/Protocol_1_13.cpp
+++ b/src/Protocol/Protocol_1_13.cpp
@@ -463,7 +463,6 @@ UInt32 cProtocol_1_13::GetProtocolMobType(eMonsterType a_MobType)
 		case mtZombiePigman:          return 53;
 		case mtZombieHorse:           return 88;
 		case mtZombieVillager:        return 89;
-
 		default:                      return 0;
 	}
 	UNREACHABLE("Unsupported mob type");
@@ -599,7 +598,6 @@ UInt8 cProtocol_1_13::GetEntityMetadataID(EntityMetadata a_Metadata)
 		case EntityMetadata::AbstractSkeletonArmsSwinging:
 		case EntityMetadata::ZombieUnusedWasType: break;
 	}
-
 	UNREACHABLE("Retrieved invalid metadata for protocol");
 }
 
@@ -631,7 +629,6 @@ UInt8 cProtocol_1_13::GetEntityMetadataID(EntityMetadataType a_FieldType)
 		case EntityMetadataType::OptVarInt:    return 17;
 		case EntityMetadataType::Pose:         return 18;
 	}
-
 	UNREACHABLE("Translated invalid metadata type for protocol");
 }
 
@@ -1307,10 +1304,9 @@ void cProtocol_1_13::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_Mo
 		case mtVindicator:
 
 		case mtHusk:
-
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_13::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_13::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -1331,10 +1327,6 @@ void cProtocol_1_13::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_Mo
 			break;
 		}
 
-		case mtInvalidType:
-		{
-			break;
-		}
 		default: UNREACHABLE("cProtocol_1_13::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
diff --git a/src/Protocol/Protocol_1_8.cpp b/src/Protocol/Protocol_1_8.cpp
index 003fc75e2..91c132c8b 100644
--- a/src/Protocol/Protocol_1_8.cpp
+++ b/src/Protocol/Protocol_1_8.cpp
@@ -3848,7 +3848,7 @@ void cProtocol_1_8_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 		case mtZombieHorse:
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_8::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_8::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -3865,10 +3865,7 @@ void cProtocol_1_8_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 			// Allowed mobs without additional metadata
 			break;
 		}
-		case mtInvalidType:
-		{
-			break;
-		}
+
 		default: UNREACHABLE("cProtocol_1_8::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
@@ -4029,7 +4026,7 @@ UInt8 cProtocol_1_8_0::GetProtocolEntityType(const cEntity & a_Entity)
 		case Type::etPlayer:
 		case Type::etMonster:
 		case Type::etExpOrb:
-		case Type::etPainting: UNREACHABLE("Tried to spawn an unhandled entity");
+		case Type::etPainting: break;
 	}
 	UNREACHABLE("Unhandled entity kind");
 }
diff --git a/src/Protocol/Protocol_1_9.cpp b/src/Protocol/Protocol_1_9.cpp
index e2396ce0e..5506aec1a 100644
--- a/src/Protocol/Protocol_1_9.cpp
+++ b/src/Protocol/Protocol_1_9.cpp
@@ -2150,7 +2150,7 @@ void cProtocol_1_9_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 		case mtShulker:
 		{
 			// Todo: Mobs not added yet. Grouped ones have the same metadata
-			UNREACHABLE("cProtocol_1_9::WriteMobMetadata: received unimplemented type");
+			ASSERT(!"cProtocol_1_9::WriteMobMetadata: received unimplemented type");
 			break;
 		}
 
@@ -2167,10 +2167,7 @@ void cProtocol_1_9_0::WriteMobMetadata(cPacketizer & a_Pkt, const cMonster & a_M
 			// Entities without additional metadata
 			break;
 		}
-		case mtInvalidType:
-		{
 
-		}
 		default: UNREACHABLE("cProtocol_1_9::WriteMobMetadata: received mob of invalid type");
 	}  // switch (a_Mob.GetType())
 }
diff --git a/src/WorldStorage/NamespaceSerializer.cpp b/src/WorldStorage/NamespaceSerializer.cpp
index 4d3d1a544..088714cd1 100644
--- a/src/WorldStorage/NamespaceSerializer.cpp
+++ b/src/WorldStorage/NamespaceSerializer.cpp
@@ -133,7 +133,6 @@ std::string_view NamespaceSerializer::From(const Statistic a_ID)
 		case Statistic::AchBreedCow:                  return "cuberite:achievement.breedCow";
 		case Statistic::AchDiamondsToYou:             return "cuberite:achievement.diamondsToYou";
 	}
-
 	UNREACHABLE("Tried to save unhandled statistic");
 }
 
@@ -216,7 +215,6 @@ std::string_view NamespaceSerializer::From(eMonsterType a_ID)
 		case mtZombieVillager: return "zombie_villager";
 		case mtInvalidType:    break;
 	}
-
 	UNREACHABLE("Tried to save unknown monster type");
 }