Deal with covered switches consistently (#4161)

* Fixes a number of "<function>: not all control paths return a value" warnings on MSVC.

* Introduces the UNREACHABLE global macro and uses it instead of conditionally compiled switch defaults.

* Move cNBTParseErrorCategory from FastNBT.h into FastNBT.cpp to prevent bad calls to message()

src/Bindings/LuaState.cpp

@@ -994,6 +994,7 @@ void cLuaState::Push(cEntity * a_Entity)
 						return "cEntity";
 					}
 				}  // switch (EntityType)
+				UNREACHABLE("Unsupported entity type");
 			}();
 		tolua_pushusertype(m_LuaState, a_Entity, ClassName);
 	}

src/BlockArea.cpp

@@ -2458,129 +2458,124 @@ void cBlockArea::MergeByStrategy(const cBlockArea & a_Src, int a_RelX, int a_Rel
 	int DstOffZ = std::max(0,  a_RelZ);  // Offset in Dst where to start writing
 	int SizeZ   = std::min(a_Src.GetSizeZ() - SrcOffZ, GetSizeZ() - DstOffZ);  // How many blocks to copy
 
-	switch (a_Strategy)
+	[&]
 	{
-		case cBlockArea::msOverwrite:
+		switch (a_Strategy)
 		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorOverwrite<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msOverwrite
+			case cBlockArea::msOverwrite:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorOverwrite<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msOverwrite
 
-		case cBlockArea::msFillAir:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorFillAir<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msFillAir
+			case cBlockArea::msFillAir:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorFillAir<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msFillAir
 
-		case cBlockArea::msImprint:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorImprint<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msImprint
+			case cBlockArea::msImprint:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorImprint<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msImprint
 
-		case cBlockArea::msLake:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorLake<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msLake
+			case cBlockArea::msLake:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorLake<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msLake
 
-		case cBlockArea::msSpongePrint:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorSpongePrint<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msSpongePrint
+			case cBlockArea::msSpongePrint:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorSpongePrint<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msSpongePrint
 
-		case cBlockArea::msDifference:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorDifference<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msDifference
+			case cBlockArea::msDifference:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorDifference<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msDifference
 
-		case cBlockArea::msSimpleCompare:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorSimpleCompare<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msSimpleCompare
+			case cBlockArea::msSimpleCompare:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorSimpleCompare<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msSimpleCompare
 
-		case cBlockArea::msMask:
-		{
-			InternalMergeBlocks<MetasValid, MergeCombinatorMask<MetasValid> >(
-				GetBlockTypes(), a_Src.GetBlockTypes(),
-				DstMetas, SrcMetas,
-				SizeX, SizeY, SizeZ,
-				SrcOffX, SrcOffY, SrcOffZ,
-				DstOffX, DstOffY, DstOffZ,
-				a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
-				m_Size.x, m_Size.y, m_Size.z
-			);
-			break;
-		}  // case msMask
-
-		#ifndef __clang__  // Clang complains about a default case in a switch with all cases covered
-		default:
-		{
-			LOGWARNING("Unknown block area merge strategy: %d", a_Strategy);
-			ASSERT(!"Unknown block area merge strategy");
-			return;
-		}
-		#endif
-	}  // switch (a_Strategy)
+			case cBlockArea::msMask:
+			{
+				InternalMergeBlocks<MetasValid, MergeCombinatorMask<MetasValid> >(
+					GetBlockTypes(), a_Src.GetBlockTypes(),
+					DstMetas, SrcMetas,
+					SizeX, SizeY, SizeZ,
+					SrcOffX, SrcOffY, SrcOffZ,
+					DstOffX, DstOffY, DstOffZ,
+					a_Src.GetSizeX(), a_Src.GetSizeY(), a_Src.GetSizeZ(),
+					m_Size.x, m_Size.y, m_Size.z
+				);
+				return;
+			}  // case msMask
+		}  // switch (a_Strategy)
+		UNREACHABLE("Unsupported block area merge strategy");
+	}();
 
 	if (HasBlockEntities())
 	{

src/BlockID.cpp

@@ -388,12 +388,7 @@ AString DamageTypeToString(eDamageType a_DamageType)
 		case dtSuffocating:     return "dtSuffocation";
 		case dtExplosion:       return "dtExplosion";
 	}
-
-	// Unknown damage type:
-	ASSERT(!"Unknown DamageType");
-	#ifndef __clang__
-		return Printf("dtUnknown_%d", static_cast<int>(a_DamageType));
-	#endif
+	UNREACHABLE("Unsupported damage type");
 }
 
 

src/Blocks/BlockButton.h

@@ -92,10 +92,7 @@ public:
 				return 0x0;
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	inline static eBlockFace BlockMetaDataToBlockFace(NIBBLETYPE a_Meta)

src/Blocks/BlockCocoaPod.h

@@ -82,10 +82,7 @@ public:
 				return 0;
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	virtual ColourID GetMapBaseColourID(NIBBLETYPE a_Meta) override

src/Blocks/BlockLadder.h

@@ -60,10 +60,7 @@ public:
 				return 0x2;
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	static eBlockFace MetaDataToDirection(NIBBLETYPE a_MetaData)

src/Blocks/BlockLever.h

@@ -65,10 +65,7 @@ public:
 			case BLOCK_FACE_YM:   return 0x0;
 			case BLOCK_FACE_NONE: return 0x6;
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	inline static eBlockFace BlockMetaDataToBlockFace(NIBBLETYPE a_Meta)

src/Blocks/BlockQuartz.h

@@ -63,10 +63,7 @@ public:
 				return a_QuartzMeta;  // No idea, give a special meta (all sides the same)
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	virtual ColourID GetMapBaseColourID(NIBBLETYPE a_Meta) override

src/Blocks/BlockSideways.h

@@ -64,10 +64,7 @@ public:
 				return a_Meta | 0xC;  // No idea, give a special meta
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 } ;
 

src/Blocks/BlockTrapdoor.h

@@ -83,10 +83,7 @@ public:
 				return 0;
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	inline static eBlockFace BlockMetaDataToBlockFace(NIBBLETYPE a_Meta)

src/Blocks/BlockTripwireHook.h

@@ -45,10 +45,7 @@ public:
 				return 0x0;
 			}
 		}
-		#if !defined(__clang__)
-			ASSERT(!"Unknown BLOCK_FACE");
-			return 0;
-		#endif
+		UNREACHABLE("Unsupported block face");
 	}
 
 	inline static eBlockFace MetadataToDirection(NIBBLETYPE a_Meta)

src/Defines.h

@@ -277,8 +277,7 @@ inline const char * ClickActionToString(int a_ClickAction)
 
 		case caUnknown:                      return "caUnknown";
 	}
-	ASSERT(!"Unknown click action");
-	return "caUnknown";
+	UNREACHABLE("Unknown click action");
 }
 
 
@@ -299,12 +298,9 @@ inline eBlockFace MirrorBlockFaceY(eBlockFace a_BlockFace)
 		case BLOCK_FACE_YP:
 		{
 			return a_BlockFace;
-		};
+		}
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown BLOCK_FACE");
-		return a_BlockFace;
-	#endif
+	UNREACHABLE("Unsupported block face");
 }
 
 
@@ -327,10 +323,7 @@ inline eBlockFace RotateBlockFaceCCW(eBlockFace a_BlockFace)
 			return a_BlockFace;
 		}
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown BLOCK_FACE");
-		return a_BlockFace;
-	#endif
+	UNREACHABLE("Unsupported block face");
 }
 
 
@@ -350,12 +343,9 @@ inline eBlockFace RotateBlockFaceCW(eBlockFace a_BlockFace)
 		case BLOCK_FACE_YP:
 		{
 			return a_BlockFace;
-		};
+		}
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown BLOCK_FACE");
-		return a_BlockFace;
-	#endif
+	UNREACHABLE("Unsupported block face");
 }
 
 
@@ -374,10 +364,7 @@ inline eBlockFace ReverseBlockFace(eBlockFace  a_BlockFace)
 		case BLOCK_FACE_ZM:   return BLOCK_FACE_ZP;
 		case BLOCK_FACE_NONE: return a_BlockFace;
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown BLOCK_FACE");
-		return a_BlockFace;
-	#endif
+	UNREACHABLE("Unsupported block face");
 }
 
 
@@ -397,10 +384,7 @@ inline AString BlockFaceToString(eBlockFace a_BlockFace)
 		case BLOCK_FACE_ZP: return "BLOCK_FACE_ZP";
 		case BLOCK_FACE_NONE: return "BLOCK_FACE_NONE";
 	}
-	// clang optimisises this line away then warns that it has done so.
-	#if !defined(__clang__)
-		return Printf("Unknown BLOCK_FACE: %d", a_BlockFace);
-	#endif
+	UNREACHABLE("Unsupported block face");
 }
 
 

src/Entities/ArrowEntity.cpp

@@ -66,10 +66,7 @@ bool cArrowEntity::CanPickup(const cPlayer & a_Player) const
 		case psInSurvivalOrCreative: return (a_Player.IsGameModeSurvival() || a_Player.IsGameModeCreative());
 		case psInCreative:           return a_Player.IsGameModeCreative();
 	}
-	ASSERT(!"Unhandled pickup state");
-	#ifndef __clang__
-		return false;
-	#endif
+	UNREACHABLE("Unsupported arrow pickup state");
 }
 
 

src/Entities/Boat.cpp

@@ -207,10 +207,7 @@ AString cBoat::MaterialToString(eMaterial a_Material)
 		case bmAcacia:  return "acacia";
 		case bmDarkOak: return "dark_oak";
 	}
-	ASSERT(!"Unhandled boat material");
-	#ifndef __clang__
-		return "oak";
-	#endif
+	UNREACHABLE("Unsupported boat material");
 }
 
 
@@ -264,9 +261,7 @@ cItem cBoat::MaterialToItem(eMaterial a_Material)
 		case bmAcacia:  return cItem(E_ITEM_ACACIA_BOAT);
 		case bmDarkOak: return cItem(E_ITEM_DARK_OAK_BOAT);
 	}
-	#ifndef __clang__
-		return cItem(E_ITEM_BOAT);
-	#endif
+	UNREACHABLE("Unsupported boat material");
 }
 
 

src/Entities/Entity.cpp

@@ -640,10 +640,7 @@ bool cEntity::ArmorCoversAgainst(eDamageType a_DamageType)
 			return true;
 		}
 	}
-	ASSERT(!"Invalid damage type!");
-	#ifndef __clang__
-		return false;
-	#endif
+	UNREACHABLE("Unsupported damage type");
 }
 
 

src/Entities/EntityEffect.cpp

@@ -217,11 +217,7 @@ std::unique_ptr<cEntityEffect> cEntityEffect::CreateEntityEffect(cEntityEffect::
 		case cEntityEffect::effWeakness:       return cpp14::make_unique<cEntityEffectWeakness      >(a_Duration, a_Intensity, a_DistanceModifier);
 		case cEntityEffect::effWither:         return cpp14::make_unique<cEntityEffectWither        >(a_Duration, a_Intensity, a_DistanceModifier);
 	}
-
-	ASSERT(!"Unhandled entity effect type!");
-	#ifndef __clang__
-		return {};
-	#endif
+	UNREACHABLE("Unsupported entity effect");
 }
 
 

src/Entities/HangingEntity.h

@@ -60,40 +60,34 @@ protected:
 	/** Converts protocol hanging item facing to eBlockFace values */
 	inline static eBlockFace ProtocolFaceToBlockFace(Byte a_ProtocolFace)
 	{
-		eBlockFace Dir;
-
 		// The client uses different values for item frame directions and block faces. Our constants are for the block faces, so we convert them here to item frame faces
 		switch (a_ProtocolFace)
 		{
-			case 0: Dir = BLOCK_FACE_ZP; break;
-			case 2: Dir = BLOCK_FACE_ZM; break;
-			case 1: Dir = BLOCK_FACE_XM; break;
-			case 3: Dir = BLOCK_FACE_XP; break;
+			case 0: return BLOCK_FACE_ZP;
+			case 2: return BLOCK_FACE_ZM;
+			case 1: return BLOCK_FACE_XM;
+			case 3: return BLOCK_FACE_XP;
 			default:
 			{
 				LOGINFO("Invalid facing (%d) in a cHangingEntity, adjusting to BLOCK_FACE_XP.", a_ProtocolFace);
 				ASSERT(!"Tried to convert a bad facing!");
 
-				Dir = cHangingEntity::ProtocolFaceToBlockFace(3);
+				return cHangingEntity::ProtocolFaceToBlockFace(3);
 			}
 		}
-
-		return Dir;
 	}
 
 
 	/** Converts eBlockFace values to protocol hanging item faces */
 	inline static Byte BlockFaceToProtocolFace(eBlockFace a_BlockFace)
 	{
-		Byte Dir;
-
 		// The client uses different values for item frame directions and block faces. Our constants are for the block faces, so we convert them here to item frame faces
 		switch (a_BlockFace)
 		{
-			case BLOCK_FACE_ZP: Dir = 0; break;
-			case BLOCK_FACE_ZM: Dir = 2; break;
-			case BLOCK_FACE_XM: Dir = 1; break;
-			case BLOCK_FACE_XP: Dir = 3; break;
+			case BLOCK_FACE_ZP: return 0;
+			case BLOCK_FACE_ZM: return 2;
+			case BLOCK_FACE_XM: return 1;
+			case BLOCK_FACE_XP: return 3;
 			case BLOCK_FACE_YP:
 			case BLOCK_FACE_YM:
 			case BLOCK_FACE_NONE:
@@ -102,19 +96,10 @@ protected:
 				// LOGINFO("Invalid facing (%d) in a cHangingEntity, adjusting to BLOCK_FACE_XP.", a_BlockFace);
 				// ASSERT(!"Tried to convert a bad facing!");
 
-				Dir = cHangingEntity::BlockFaceToProtocolFace(BLOCK_FACE_XP);
-				break;
+				return cHangingEntity::BlockFaceToProtocolFace(BLOCK_FACE_XP);
 			}
-			#if !defined(__clang__)
-			default:
-			{
-				ASSERT(!"Unknown BLOCK_FACE");
-				return 0;
-			}
-			#endif
 		}
-
-		return Dir;
+		UNREACHABLE("Unsupported block face");
 	}
 };  // tolua_export
 

src/Entities/Player.cpp

@@ -1060,36 +1060,31 @@ void cPlayer::KilledBy(TakeDamageInfo & a_TDI)
 
 	if ((a_TDI.Attacker == nullptr) && m_World->ShouldBroadcastDeathMessages())
 	{
-		AString DamageText;
-		switch (a_TDI.DamageType)
-		{
-			case dtRangedAttack: DamageText = "was shot"; break;
-			case dtLightning: DamageText = "was plasmified by lightining"; break;
-			case dtFalling: DamageText = GetRandomProvider().RandBool() ? "fell to death" : "hit the ground too hard"; break;
-			case dtDrowning: DamageText = "drowned"; break;
-			case dtSuffocating: DamageText = GetRandomProvider().RandBool() ? "git merge'd into a block" : "fused with a block"; break;
-			case dtStarving: DamageText = "forgot the importance of food"; break;
-			case dtCactusContact: DamageText = "was impaled on a cactus"; break;
-			case dtLavaContact: DamageText = "was melted by lava"; break;
-			case dtPoisoning: DamageText = "died from septicaemia"; break;
-			case dtWithering: DamageText = "is a husk of their former selves"; break;
-			case dtOnFire: DamageText = "forgot to stop, drop, and roll"; break;
-			case dtFireContact: DamageText = "burnt themselves to death"; break;
-			case dtInVoid: DamageText = "somehow fell out of the world"; break;
-			case dtPotionOfHarming: DamageText = "was magicked to death"; break;
-			case dtEnderPearl: DamageText = "misused an ender pearl"; break;
-			case dtAdmin: DamageText = "was administrator'd"; break;
-			case dtExplosion: DamageText = "blew up"; break;
-			case dtAttack: DamageText = "was attacked by thin air"; break;
-			#ifndef __clang__
-			default:
+		const AString DamageText = [&]
 			{
-				ASSERT(!"Unknown damage type");
-				DamageText = "died, somehow; we've no idea how though";
-				break;
-			}
-			#endif  // __clang__
-		}
+				switch (a_TDI.DamageType)
+				{
+					case dtRangedAttack:    return "was shot";
+					case dtLightning:       return "was plasmified by lightining";
+					case dtFalling:         return GetRandomProvider().RandBool() ? "fell to death" : "hit the ground too hard";
+					case dtDrowning:        return "drowned";
+					case dtSuffocating:     return GetRandomProvider().RandBool() ? "git merge'd into a block" : "fused with a block";
+					case dtStarving:        return "forgot the importance of food";
+					case dtCactusContact:   return "was impaled on a cactus";
+					case dtLavaContact:     return "was melted by lava";
+					case dtPoisoning:       return "died from septicaemia";
+					case dtWithering:       return "is a husk of their former selves";
+					case dtOnFire:          return "forgot to stop, drop, and roll";
+					case dtFireContact:     return "burnt themselves to death";
+					case dtInVoid:          return "somehow fell out of the world";
+					case dtPotionOfHarming: return "was magicked to death";
+					case dtEnderPearl:      return "misused an ender pearl";
+					case dtAdmin:           return "was administrator'd";
+					case dtExplosion:       return "blew up";
+					case dtAttack:          return "was attacked by thin air";
+				}
+				UNREACHABLE("Unsupported damage type");
+			}();
 		AString DeathMessage = Printf("%s %s", GetName().c_str(), DamageText.c_str());
 		PluginManager->CallHookKilled(*this, a_TDI, DeathMessage);
 		if (DeathMessage != AString(""))

src/Entities/ProjectileEntity.cpp

@@ -356,10 +356,7 @@ AString cProjectileEntity::GetMCAClassName(void) const
 		case pkFirework:      return "Firework";
 		case pkFishingFloat:  return "";  // Unknown, perhaps MC doesn't save this?
 	}
-	ASSERT(!"Unhandled projectile entity kind!");
-	#ifndef __clang__
-		return "";
-	#endif
+	UNREACHABLE("Unsupported projectile kind");
 }
 
 

src/Generating/MineShafts.cpp

@@ -767,33 +767,30 @@ void cMineShaftCorridor::PlaceChest(cChunkDesc & a_ChunkDesc)
 	int BlockZ = a_ChunkDesc.GetChunkZ() * cChunkDef::Width;
 	int x, z;
 	NIBBLETYPE Meta = 0;
-	switch (m_Direction)
+	[&]
 	{
-		case dirXM:
-		case dirXP:
+		switch (m_Direction)
 		{
-			x = m_BoundingBox.p1.x + m_ChestPosition - BlockX;
-			z = m_BoundingBox.p1.z - BlockZ;
-			Meta = E_META_CHEST_FACING_ZP;
-			break;
-		}
+			case dirXM:
+			case dirXP:
+			{
+				x = m_BoundingBox.p1.x + m_ChestPosition - BlockX;
+				z = m_BoundingBox.p1.z - BlockZ;
+				Meta = E_META_CHEST_FACING_ZP;
+				return;
+			}
 
-		case dirZM:
-		case dirZP:
-		{
-			x = m_BoundingBox.p1.x - BlockX;
-			z = m_BoundingBox.p1.z + m_ChestPosition - BlockZ;
-			Meta = E_META_CHEST_FACING_XP;
-			break;
-		}
-		#if !defined(__clang__)
-		default:
-		{
-			ASSERT(!"Unknown direction");
-			return;
-		}
-		#endif
-	}  // switch (Dir)
+			case dirZM:
+			case dirZP:
+			{
+				x = m_BoundingBox.p1.x - BlockX;
+				z = m_BoundingBox.p1.z + m_ChestPosition - BlockZ;
+				Meta = E_META_CHEST_FACING_XP;
+				return;
+			}
+		}  // switch (Dir)
+		UNREACHABLE("Unsupported corridor direction");
+	}();
 
 	if (
 		(x >= 0) && (x < cChunkDef::Width) &&

src/Generating/PiecePool.cpp

@@ -200,10 +200,7 @@ Vector3i cPiece::cConnector::AddDirection(const Vector3i & a_Pos, eDirection a_D
 		case dirYP_XP_ZM: return Vector3i(a_Pos.x,     a_Pos.y + 1, a_Pos.z);
 		case dirYP_XP_ZP: return Vector3i(a_Pos.x,     a_Pos.y + 1, a_Pos.z);
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown connector direction");
-		return a_Pos;
-	#endif
+	UNREACHABLE("Unsupported connector direction");
 }
 
 
@@ -229,10 +226,7 @@ const char * cPiece::cConnector::DirectionToString(eDirection a_Direction)
 		case dirYP_XP_ZM: return "y+x+z-";
 		case dirYP_XP_ZP: return "y+x+z+";
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown connector direction");
-		return "<unknown>";
-	#endif
+	UNREACHABLE("Unsupported connector direction");
 }
 
 
@@ -288,10 +282,7 @@ cPiece::cConnector::eDirection cPiece::cConnector::RotateDirection(eDirection a_
 		case dirYP_XP_ZM: return dirYP_XM_ZP;
 		case dirYP_XP_ZP: return dirYP_XM_ZM;
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown connector direction");
-		return a_Direction;
-	#endif
+	UNREACHABLE("Unsupported connector direction");
 }
 
 
@@ -318,10 +309,7 @@ cPiece::cConnector::eDirection cPiece::cConnector::RotateDirectionCCW(eDirection
 		case dirYP_XP_ZM: return dirYP_XM_ZM;
 		case dirYP_XP_ZP: return dirYP_XP_ZM;
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown connector direction");
-		return a_Direction;
-	#endif
+	UNREACHABLE("Unsupported connector direction");
 }
 
 
@@ -348,10 +336,7 @@ cPiece::cConnector::eDirection cPiece::cConnector::RotateDirectionCW(eDirection
 		case dirYP_XP_ZM: return dirYP_XP_ZP;
 		case dirYP_XP_ZP: return dirYP_XM_ZP;
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown connector direction");
-		return a_Direction;
-	#endif
+	UNREACHABLE("Unsupported connector direction");
 }
 
 

src/Generating/StructGen.cpp

@@ -274,6 +274,7 @@ int cStructGenTrees::GetNumTrees(
 				return 0;
 			}
 		}
+		UNREACHABLE("Unsupported biome");
 	};
 
 	int NumTrees = 0;

src/Globals.h

@@ -352,6 +352,9 @@ template class SizeChecker<UInt8,  1>;
 	#define assert_test(x) ( !!(x) || (assert(!#x), exit(1), 0))
 #endif
 
+/** 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__); PrintStackTrace(); std::terminate(); } while (false)
+
 
 
 

src/HTTP/NameValueParser.cpp

@@ -404,10 +404,7 @@ bool cNameValueParser::Finish(void)
 			return true;
 		}
 	}
-	ASSERT(!"Unhandled parser state!");
-	#ifndef __clang__
-		return false;
-	#endif
+	UNREACHABLE("Unsupported name value parser state");
 }
 
 

src/Items/ItemAxe.h

@@ -27,6 +27,7 @@ public:
 			case dlaBreakBlock:         return 1;
 			case dlaBreakBlockInstant:  return 0;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 
 

src/Items/ItemHoe.h

@@ -75,5 +75,6 @@ public:
 			case dlaBreakBlock:         return 0;
 			case dlaBreakBlockInstant:  return 0;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 } ;

src/Items/ItemPickaxe.h

@@ -26,6 +26,7 @@ public:
 			case dlaBreakBlock:         return 1;
 			case dlaBreakBlockInstant:  return 0;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 
 

src/Items/ItemShears.h

@@ -69,6 +69,7 @@ public:
 			case dlaBreakBlock:         return 0;
 			case dlaBreakBlockInstant:  return 1;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 
 

src/Items/ItemShovel.h

@@ -31,6 +31,7 @@ public:
 			case dlaBreakBlock:        return 1;
 			case dlaBreakBlockInstant: return 0;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 
 

src/Items/ItemSword.h

@@ -50,6 +50,7 @@ public:
 			case dlaBreakBlock:         return 2;
 			case dlaBreakBlockInstant:  return 0;
 		}
+		UNREACHABLE("Unsupported durability loss action");
 	}
 
 

src/MobCensus.cpp

@@ -48,10 +48,7 @@ int cMobCensus::GetCapMultiplier(cMonster::eFamily a_MobFamily)
 			return -1;
 		}
 	}
-	#if !defined(__clang__)
-		ASSERT(!"Unknown mob family");
-		return -1;
-	#endif
+	UNREACHABLE("Unsupported mob family");
 }
 
 

src/Mobs/PathFinder.cpp

@@ -152,14 +152,8 @@ ePathFinderStatus cPathFinder::GetNextWayPoint(cChunk & a_Chunk, const Vector3d
 				return ePathFinderStatus::PATH_FOUND;
 			}
 		}
-		#ifndef __clang__
-		default:
-		{
-			return ePathFinderStatus::PATH_FOUND;
-			// Fixes GCC warning: "control reaches end of non-void function".
-		}
-		#endif
 	}
+	UNREACHABLE("Unsupported path finder status");
 }
 
 

src/Protocol/PacketID.cpp

@@ -79,11 +79,7 @@ UInt32 cProtocol_1_9_0::GetPacketId(eOutgoingPackets a_Packet)
 		case sendWindowOpen:            return 0x13;
 		case sendWindowProperty:        return 0x15;
 	}
-	ASSERT(!"Retrieving packet ID for unknown packet type");
-	#ifndef __clang__
-		LOGWARNING("Retrieving packet ID for unknown packet type %d!", a_Packet);
-		return 0;
-	#endif
+	UNREACHABLE("Unsupported outgoing packet type");
 }
 
 

src/Scoreboard.cpp

@@ -30,13 +30,8 @@ AString cObjective::TypeToString(eType a_Type)
 		case otStatBlockMine:      return "stat.mineBlock";
 		case otStatEntityKill:     return "stat.killEntity";
 		case otStatEntityKilledBy: return "stat.entityKilledBy";
-
-		// clang optimisises this line away then warns that it has done so.
-		#if !defined(__clang__)
-		default: return "";
-		#endif
 	}
-
+	UNREACHABLE("Unsupported objective type");
 }
 
 

src/World.cpp

@@ -492,11 +492,7 @@ int cWorld::GetDefaultWeatherInterval(eWeather a_Weather)
 			return Random.RandInt(m_MinThunderStormTicks, m_MaxThunderStormTicks);
 		}
 	}
-
-	#ifndef __clang__
-		ASSERT(!"Unknown weather");
-		return -1;
-	#endif
+	UNREACHABLE("Unsupported weather");
 }
 
 
@@ -851,19 +847,17 @@ eWeather cWorld::ChooseNewWeather()
 	switch (m_Weather)
 	{
 		case eWeather_Sunny:
-		case eWeather_ThunderStorm: return eWeather_Rain;
-
+		case eWeather_ThunderStorm:
+		{
+			return eWeather_Rain;
+		}
 		case eWeather_Rain:
 		{
 			// 1 / 8 chance of turning into a thunderstorm
 			return GetRandomProvider().RandBool(0.125) ? eWeather_ThunderStorm : eWeather_Sunny;
 		}
 	}
-
-	#ifndef __clang__
-		ASSERT(!"Unknown weather");
-		return eWeather_Sunny;
-	#endif
+	UNREACHABLE("Unsupported weather");
 }
 
 

src/WorldStorage/FastNBT.cpp

@@ -35,6 +35,35 @@ static const int MAX_LIST_ITEMS = 10000;
 ////////////////////////////////////////////////////////////////////////////////
 // cNBTParseErrorCategory:
 
+namespace
+{
+
+class cNBTParseErrorCategory final :
+	public std::error_category
+{
+	cNBTParseErrorCategory() = default;
+public:
+	/** Category name */
+	virtual const char * name() const NOEXCEPT override
+	{
+		return "NBT parse error";
+	}
+
+	/** Maps a parse error code to an error message */
+	virtual AString message(int a_Condition) const override;
+
+	/** Returns the canonical error category instance. */
+	static const cNBTParseErrorCategory & Get() NOEXCEPT
+	{
+		static cNBTParseErrorCategory Category;
+		return Category;
+	}
+};
+
+
+
+
+
 AString cNBTParseErrorCategory::message(int a_Condition) const
 {
 	switch (static_cast<eNBTParseError>(a_Condition))
@@ -91,22 +120,19 @@ AString cNBTParseErrorCategory::message(int a_Condition) const
 		{
 			return "Unknown tag";
 		}
-
-		#ifdef __clang__
-			#pragma clang diagnostic push
-			#pragma clang diagnostic ignored "-Wcovered-switch-default"
-			#pragma clang diagnostic ignored "-Wunreachable-code"
-		#endif
-
-		default:
-		{
-			return "<unrecognized error>";
-		}
-
-		#ifdef __clang__
-			#pragma clang diagnostic pop
-		#endif
 	}
+	UNREACHABLE("Unsupported nbt parse error");
+}
+
+}  // namespace (anonymous)
+
+
+
+
+
+std::error_code make_error_code(eNBTParseError a_Err) NOEXCEPT
+{
+	return { static_cast<int>(a_Err), cNBTParseErrorCategory::Get() };
 }
 
 
@@ -337,14 +363,12 @@ eNBTParseError cParsedNBT::ReadTag(void)
 			return eNBTParseError::npSuccess;
 		}
 
-		#if !defined(__clang__)
-		default:
-		#endif
 		case TAG_Min:
 		{
 			return eNBTParseError::npUnknownTag;
 		}
 	}  // switch (iType)
+	UNREACHABLE("Unsupported nbt tag type");
 }
 
 #undef CASE_SIMPLE_TAG

src/WorldStorage/FastNBT.h

@@ -125,41 +125,8 @@ enum class eNBTParseError
 	npUnknownTag,
 };
 
-
-
-
-
-class cNBTParseErrorCategory final:
-	public std::error_category
-{
-	cNBTParseErrorCategory() = default;
-public:
-	/** Category name */
-	virtual const char * name() const NOEXCEPT override
-	{
-		return "NBT parse error";
-	}
-
-	/** Maps a parse error code to an error message */
-	virtual AString message(int a_Condition) const override;
-
-	/** Returns the canonical error category instance. */
-	static const cNBTParseErrorCategory & Get()
-	{
-		static cNBTParseErrorCategory Category;
-		return Category;
-	}
-};
-
-
-
-
-
 // The following is required to make an error_code constructible from an eNBTParseError
-inline std::error_code make_error_code(eNBTParseError a_Err) NOEXCEPT
-{
-	return { static_cast<int>(a_Err), cNBTParseErrorCategory::Get() };
-}
+std::error_code make_error_code(eNBTParseError a_Err) NOEXCEPT;
 
 namespace std
 {

src/mbedTLS++/SslConfig.cpp

@@ -145,10 +145,8 @@ void cSslConfig::SetAuthMode(const eSslAuthMode a_AuthMode)
 			case eSslAuthMode::Optional: return MBEDTLS_SSL_VERIFY_OPTIONAL;
 			case eSslAuthMode::Required: return MBEDTLS_SSL_VERIFY_REQUIRED;
 			case eSslAuthMode::Unset:    return MBEDTLS_SSL_VERIFY_UNSET;
-			#ifndef __clang__
-				default:                 return MBEDTLS_SSL_VERIFY_OPTIONAL;
-			#endif
 		}
+		UNREACHABLE("Unsupported SSL auth mode");
 	}();
 
 	mbedtls_ssl_conf_authmode(&m_Config, Mode);

tests/HTTP/CMakeLists.txt

@@ -15,6 +15,8 @@ set (HTTP_SRCS
 	${CMAKE_SOURCE_DIR}/src/HTTP/TransferEncodingParser.cpp
 	${CMAKE_SOURCE_DIR}/src/HTTP/UrlClient.cpp
 	${CMAKE_SOURCE_DIR}/src/HTTP/UrlParser.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/StackTrace.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/WinStackWalker.cpp
 	${CMAKE_SOURCE_DIR}/src/StringUtils.cpp
 )
 
@@ -25,6 +27,8 @@ set (HTTP_HDRS
 	${CMAKE_SOURCE_DIR}/src/HTTP/TransferEncodingParser.h
 	${CMAKE_SOURCE_DIR}/src/HTTP/UrlClient.h
 	${CMAKE_SOURCE_DIR}/src/HTTP/UrlParser.h
+	${CMAKE_SOURCE_DIR}/src/OSSupport/StackTrace.h
+	${CMAKE_SOURCE_DIR}/src/OSSupport/WinStackWalker.h
 	${CMAKE_SOURCE_DIR}/src/StringUtils.h
 )
 

tests/Network/CMakeLists.txt

@@ -18,7 +18,9 @@ set (Network_SRCS
 	${CMAKE_SOURCE_DIR}/src/OSSupport/NetworkLookup.cpp
 	${CMAKE_SOURCE_DIR}/src/OSSupport/NetworkSingleton.cpp
 	${CMAKE_SOURCE_DIR}/src/OSSupport/ServerHandleImpl.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/StackTrace.cpp
 	${CMAKE_SOURCE_DIR}/src/OSSupport/TCPLinkImpl.cpp
+	${CMAKE_SOURCE_DIR}/src/OSSupport/WinStackWalker.cpp
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/CtrDrbgContext.cpp
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/CryptoKey.cpp
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/EntropyContext.cpp
@@ -39,8 +41,10 @@ set (Network_HDRS
 	${CMAKE_SOURCE_DIR}/src/OSSupport/NetworkLookup.h
 	${CMAKE_SOURCE_DIR}/src/OSSupport/NetworkSingleton.h
 	${CMAKE_SOURCE_DIR}/src/OSSupport/ServerHandleImpl.h
+	${CMAKE_SOURCE_DIR}/src/OSSupport/StackTrace.h
 	${CMAKE_SOURCE_DIR}/src/OSSupport/TCPLinkImpl.h
 	${CMAKE_SOURCE_DIR}/src/OSSupport/Queue.h
+	${CMAKE_SOURCE_DIR}/src/OSSupport/WinStackWalker.h
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/CtrDrbgContext.h
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/CryptoKey.h
 	${CMAKE_SOURCE_DIR}/src/mbedTLS++/EntropyContext.h