Check that we have documented recent compiler messages

[BillWagner]

I'm almost certain we haven't added new warnings and error messages since C# 6.0 (and maybe earlier).

@jcouv is there a good list in the roslyn repo to track down what should be covered?

See #5390-comment for details.

[jcouv]

Yes, here is the list for C#. It is largely chronological.
To get details, the easiest it to load the project, and find references. That will find tests that report a given error.

[mikkelbu]

@BillWagner I just tried to compare the pages under dotnet/docs/tree/master/docs/csharp/language-reference/compiler-messages with list for C# and it seems as though are missing most of the compiler messages (we have 136 entries in docs vs. approx. 1500 values in the ErrorCode. So I think it makes sense to "chop up" this issue into a lot of smaller tasks (both make both the work and the review work manageable).

Click to expand the full table (more than 1500 rows)

Topic exists	Values in enum
	Void = InternalErrorCode.Void,
	Unknown = InternalErrorCode.Unknown,
	#region diagnostics introduced in C# 4 and earlier
X	//FTL_InternalError = 1,
	//FTL_FailedToLoadResource = 2,
	//FTL_NoMemory = 3,
	//ERR_WarningAsError = 4,
	//ERR_MissingOptionArg = 5,
X	ERR_NoMetadataFile = 6,
X	//FTL_ComPlusInit = 7,
	//FTL_MetadataImportFailure = 8, no longer used in Roslyn.
	FTL_MetadataCantOpenFile = 9,
	//ERR_FatalError = 10,
	//ERR_CantImportBase = 11,
	ERR_NoTypeDef = 12,
	//FTL_MetadataEmitFailure = 13, Roslyn does not catch stream writing exceptions. Those are propagated to the caller.
	//FTL_RequiredFileNotFound = 14,
X	//ERR_ClassNameTooLong = 15, Deprecated in favor of ERR_MetadataNameTooLong.
X	ERR_OutputWriteFailed = 16,
	ERR_MultipleEntryPoints = 17,
	//ERR_UnimplementedOp = 18,
X	ERR_BadBinaryOps = 19,
	ERR_IntDivByZero = 20,
	ERR_BadIndexLHS = 21,
	ERR_BadIndexCount = 22,
	ERR_BadUnaryOp = 23,
	//ERR_NoStdLib = 25, not used in Roslyn
	ERR_ThisInStaticMeth = 26,
	ERR_ThisInBadContext = 27,
	WRN_InvalidMainSig = 28,
X	ERR_NoImplicitConv = 29, // Requires SymbolDistinguisher.
	ERR_NoExplicitConv = 30, // Requires SymbolDistinguisher.
	ERR_ConstOutOfRange = 31,
X	ERR_AmbigBinaryOps = 34,
	ERR_AmbigUnaryOp = 35,
	ERR_InAttrOnOutParam = 36,
	ERR_ValueCantBeNull = 37,
X	//ERR_WrongNestedThis = 38, No longer given in Roslyn. Less specific ERR_ObjectRequired "An object reference is required for the non-static..."
X	ERR_NoExplicitBuiltinConv = 39, // Requires SymbolDistinguisher.
	//FTL_DebugInit = 40, Not used in Roslyn. Roslyn gives FTL_DebugEmitFailure with specific error code info.
	FTL_DebugEmitFailure = 41,
	//FTL_DebugInitFile = 42, Not used in Roslyn. Roslyn gives ERR_CantOpenFileWrite with specific error info.
	//FTL_BadPDBFormat = 43, Not used in Roslyn. Roslyn gives FTL_DebugEmitFailure with specific error code info.
X	ERR_BadVisReturnType = 50,
X	ERR_BadVisParamType = 51,
X	ERR_BadVisFieldType = 52,
	ERR_BadVisPropertyType = 53,
	ERR_BadVisIndexerReturn = 54,
	ERR_BadVisIndexerParam = 55,
	ERR_BadVisOpReturn = 56,
	ERR_BadVisOpParam = 57,
	ERR_BadVisDelegateReturn = 58,
	ERR_BadVisDelegateParam = 59,
	ERR_BadVisBaseClass = 60,
	ERR_BadVisBaseInterface = 61,
	ERR_EventNeedsBothAccessors = 65,
	ERR_EventNotDelegate = 66,
	WRN_UnreferencedEvent = 67,
	ERR_InterfaceEventInitializer = 68,
	ERR_EventPropertyInInterface = 69,
	ERR_BadEventUsage = 70,
X	ERR_ExplicitEventFieldImpl = 71,
	ERR_CantOverrideNonEvent = 72,
	ERR_AddRemoveMustHaveBody = 73,
	ERR_AbstractEventInitializer = 74,
	ERR_PossibleBadNegCast = 75,
	ERR_ReservedEnumerator = 76,
	ERR_AsMustHaveReferenceType = 77,
	WRN_LowercaseEllSuffix = 78,
	ERR_BadEventUsageNoField = 79,
	ERR_ConstraintOnlyAllowedOnGenericDecl = 80,
	ERR_TypeParamMustBeIdentifier = 81,
	ERR_MemberReserved = 82,
	ERR_DuplicateParamName = 100,
	ERR_DuplicateNameInNS = 101,
	ERR_DuplicateNameInClass = 102,
X	ERR_NameNotInContext = 103,
	ERR_AmbigContext = 104,
	WRN_DuplicateUsing = 105,
X	ERR_BadMemberFlag = 106,
	ERR_BadMemberProtection = 107,
X	WRN_NewRequired = 108,
	WRN_NewNotRequired = 109,
	ERR_CircConstValue = 110,
	ERR_MemberAlreadyExists = 111,
	ERR_StaticNotVirtual = 112,
	ERR_OverrideNotNew = 113,
	WRN_NewOrOverrideExpected = 114,
X	ERR_OverrideNotExpected = 115,
X	ERR_NamespaceUnexpected = 116,
	ERR_NoSuchMember = 117,
	ERR_BadSKknown = 118,
	ERR_BadSKunknown = 119,
X	ERR_ObjectRequired = 120,
	ERR_AmbigCall = 121,
X	ERR_BadAccess = 122,
	ERR_MethDelegateMismatch = 123,
	ERR_RetObjectRequired = 126,
	ERR_RetNoObjectRequired = 127,
	ERR_LocalDuplicate = 128,
	ERR_AssgLvalueExpected = 131,
	ERR_StaticConstParam = 132,
	ERR_NotConstantExpression = 133,
X	ERR_NotNullConstRefField = 134,
	// ERR_NameIllegallyOverrides = 135, // Not used in Roslyn anymore due to 'Single Meaning' relaxation changes
	ERR_LocalIllegallyOverrides = 136,
	ERR_BadUsingNamespace = 138,
	ERR_NoBreakOrCont = 139,
	ERR_DuplicateLabel = 140,
	ERR_NoConstructors = 143,
	ERR_NoNewAbstract = 144,
	ERR_ConstValueRequired = 145,
	ERR_CircularBase = 146,
	ERR_BadDelegateConstructor = 148,
	ERR_MethodNameExpected = 149,
	ERR_ConstantExpected = 150,
	// ERR_V6SwitchGoverningTypeValueExpected shares the same error code (CS0151) with ERR_IntegralTypeValueExpected in Dev10 compiler.
	// However ERR_IntegralTypeValueExpected is currently unused and hence being removed. If we need to generate this error in future
	// we can use error code CS0166. CS0166 was originally reserved for ERR_SwitchFallInto in Dev10, but was never used.
X	ERR_V6SwitchGoverningTypeValueExpected = 151,
	ERR_DuplicateCaseLabel = 152,
	ERR_InvalidGotoCase = 153,
	ERR_PropertyLacksGet = 154,
	ERR_BadExceptionType = 155,
	ERR_BadEmptyThrow = 156,
	ERR_BadFinallyLeave = 157,
	ERR_LabelShadow = 158,
	ERR_LabelNotFound = 159,
	ERR_UnreachableCatch = 160,
	ERR_ReturnExpected = 161,
	WRN_UnreachableCode = 162,
X	ERR_SwitchFallThrough = 163,
	WRN_UnreferencedLabel = 164,
X	ERR_UseDefViolation = 165,
	//ERR_NoInvoke = 167,
	WRN_UnreferencedVar = 168,
	WRN_UnreferencedField = 169,
	ERR_UseDefViolationField = 170,
	ERR_UnassignedThis = 171,
	ERR_AmbigQM = 172,
X	ERR_InvalidQM = 173, // Requires SymbolDistinguisher.
	ERR_NoBaseClass = 174,
	ERR_BaseIllegal = 175,
	ERR_ObjectProhibited = 176,
	ERR_ParamUnassigned = 177,
X	ERR_InvalidArray = 178,
	ERR_ExternHasBody = 179,
	ERR_AbstractAndExtern = 180,
	ERR_BadAttributeParamType = 181,
	ERR_BadAttributeArgument = 182,
	WRN_IsAlwaysTrue = 183,
	WRN_IsAlwaysFalse = 184,
	ERR_LockNeedsReference = 185,
	ERR_NullNotValid = 186,
X	ERR_UseDefViolationThis = 188,
	ERR_ArgsInvalid = 190,
	ERR_AssgReadonly = 191,
	ERR_RefReadonly = 192,
	ERR_PtrExpected = 193,
	ERR_PtrIndexSingle = 196,
	WRN_ByRefNonAgileField = 197,
	ERR_AssgReadonlyStatic = 198,
	ERR_RefReadonlyStatic = 199,
	ERR_AssgReadonlyProp = 200,
X	ERR_IllegalStatement = 201,
	ERR_BadGetEnumerator = 202,
	ERR_TooManyLocals = 204,
	ERR_AbstractBaseCall = 205,
	ERR_RefProperty = 206,
	// WRN_OldWarning_UnsafeProp = 207, // This error code is unused.
	ERR_ManagedAddr = 208,
	ERR_BadFixedInitType = 209,
	ERR_FixedMustInit = 210,
	ERR_InvalidAddrOp = 211,
	ERR_FixedNeeded = 212,
	ERR_FixedNotNeeded = 213,
	ERR_UnsafeNeeded = 214,
	ERR_OpTFRetType = 215,
	ERR_OperatorNeedsMatch = 216,
	ERR_BadBoolOp = 217,
	ERR_MustHaveOpTF = 218,
	WRN_UnreferencedVarAssg = 219,
	ERR_CheckedOverflow = 220,
	ERR_ConstOutOfRangeChecked = 221,
	ERR_BadVarargs = 224,
	ERR_ParamsMustBeArray = 225,
	ERR_IllegalArglist = 226,
	ERR_IllegalUnsafe = 227,
	//ERR_NoAccessibleMember = 228,
X	ERR_AmbigMember = 229,
	ERR_BadForeachDecl = 230,
	ERR_ParamsLast = 231,
X	ERR_SizeofUnsafe = 233,
X	ERR_DottedTypeNameNotFoundInNS = 234,
	ERR_FieldInitRefNonstatic = 236,
	ERR_SealedNonOverride = 238,
	ERR_CantOverrideSealed = 239,
	//ERR_NoDefaultArgs = 241,
	ERR_VoidError = 242,
	ERR_ConditionalOnOverride = 243,
	ERR_PointerInAsOrIs = 244,
	ERR_CallingFinalizeDeprecated = 245, //Dev10: ERR_CallingFinalizeDepracated
X	ERR_SingleTypeNameNotFound = 246,
	ERR_NegativeStackAllocSize = 247,
	ERR_NegativeArraySize = 248,
	ERR_OverrideFinalizeDeprecated = 249,
	ERR_CallingBaseFinalizeDeprecated = 250,
	WRN_NegativeArrayIndex = 251,
	WRN_BadRefCompareLeft = 252,
	WRN_BadRefCompareRight = 253,
	ERR_BadCastInFixed = 254,
	ERR_StackallocInCatchFinally = 255,
	ERR_VarargsLast = 257,
X	ERR_MissingPartial = 260,
	ERR_PartialTypeKindConflict = 261,
	ERR_PartialModifierConflict = 262,
	ERR_PartialMultipleBases = 263,
	ERR_PartialWrongTypeParams = 264,
	ERR_PartialWrongConstraints = 265,
X	ERR_NoImplicitConvCast = 266, // Requires SymbolDistinguisher.
	ERR_PartialMisplaced = 267,
	ERR_ImportedCircularBase = 268,
X	ERR_UseDefViolationOut = 269,
X	ERR_ArraySizeInDeclaration = 270,
	ERR_InaccessibleGetter = 271,
	ERR_InaccessibleSetter = 272,
	ERR_InvalidPropertyAccessMod = 273,
	ERR_DuplicatePropertyAccessMods = 274,
	ERR_PropertyAccessModInInterface = 275,
	ERR_AccessModMissingAccessor = 276,
	ERR_UnimplementedInterfaceAccessor = 277,
	WRN_PatternIsAmbiguous = 278,
	WRN_PatternStaticOrInaccessible = 279,
	WRN_PatternBadSignature = 280,
	ERR_FriendRefNotEqualToThis = 281,
	WRN_SequentialOnPartialClass = 282,
	ERR_BadConstType = 283,
X	ERR_NoNewTyvar = 304,
	ERR_BadArity = 305,
	ERR_BadTypeArgument = 306,
	ERR_TypeArgsNotAllowed = 307,
	ERR_HasNoTypeVars = 308,
X	ERR_NewConstraintNotSatisfied = 310,
X	ERR_GenericConstraintNotSatisfiedRefType = 311, // Requires SymbolDistinguisher.
	ERR_GenericConstraintNotSatisfiedNullableEnum = 312, // Uses (but doesn't require) SymbolDistinguisher.
	ERR_GenericConstraintNotSatisfiedNullableInterface = 313, // Uses (but doesn't require) SymbolDistinguisher.
	ERR_GenericConstraintNotSatisfiedTyVar = 314, // Requires SymbolDistinguisher.
	ERR_GenericConstraintNotSatisfiedValType = 315, // Requires SymbolDistinguisher.
	ERR_DuplicateGeneratedName = 316,
	// unused 317-399
	ERR_GlobalSingleTypeNameNotFound = 400,
	ERR_NewBoundMustBeLast = 401,
	WRN_MainCantBeGeneric = 402,
	ERR_TypeVarCantBeNull = 403,
	ERR_AttributeCantBeGeneric = 404,
	ERR_DuplicateBound = 405,
	ERR_ClassBoundNotFirst = 406,
	ERR_BadRetType = 407,
	ERR_DuplicateConstraintClause = 409,
	//ERR_WrongSignature = 410, unused in Roslyn
	ERR_CantInferMethTypeArgs = 411,
	ERR_LocalSameNameAsTypeParam = 412,
X	ERR_AsWithTypeVar = 413,
	WRN_UnreferencedFieldAssg = 414,
	ERR_BadIndexerNameAttr = 415,
	ERR_AttrArgWithTypeVars = 416,
X	ERR_NewTyvarWithArgs = 417,
	ERR_AbstractSealedStatic = 418,
	WRN_AmbiguousXMLReference = 419,
X	WRN_VolatileByRef = 420,
	// WRN_IncrSwitchObsolete = 422, // This error code is unused.
	ERR_ComImportWithImpl = 423,
	ERR_ComImportWithBase = 424,
	ERR_ImplBadConstraints = 425,
	ERR_DottedTypeNameNotFoundInAgg = 426,
	ERR_MethGrpToNonDel = 428,
X	// WRN_UnreachableExpr = 429, // This error code is unused.
	ERR_BadExternAlias = 430,
	ERR_ColColWithTypeAlias = 431,
	ERR_AliasNotFound = 432,
X	ERR_SameFullNameAggAgg = 433,
	ERR_SameFullNameNsAgg = 434,
	WRN_SameFullNameThisNsAgg = 435,
	WRN_SameFullNameThisAggAgg = 436,
	WRN_SameFullNameThisAggNs = 437,
	ERR_SameFullNameThisAggThisNs = 438,
	ERR_ExternAfterElements = 439,
	WRN_GlobalAliasDefn = 440,
	ERR_SealedStaticClass = 441,
	ERR_PrivateAbstractAccessor = 442,
	ERR_ValueExpected = 443,
	// WRN_UnexpectedPredefTypeLoc = 444, // This error code is unused.
X	ERR_UnboxNotLValue = 445,
X	ERR_AnonMethGrpInForEach = 446,
	//ERR_AttrOnTypeArg = 447, unused in Roslyn. The scenario for which this error exists should, and does generate a parse error.
	ERR_BadIncDecRetType = 448,
	ERR_RefValBoundMustBeFirst = 449,
	ERR_RefValBoundWithClass = 450,
	ERR_NewBoundWithVal = 451,
	ERR_RefConstraintNotSatisfied = 452,
	ERR_ValConstraintNotSatisfied = 453,
	ERR_CircularConstraint = 454,
	ERR_BaseConstraintConflict = 455,
	ERR_ConWithValCon = 456,
	ERR_AmbigUDConv = 457,
	WRN_AlwaysNull = 458,
	// ERR_AddrOnReadOnlyLocal = 459, // no longer an error
	ERR_OverrideWithConstraints = 460,
	ERR_AmbigOverride = 462,
	ERR_DecConstError = 463,
	WRN_CmpAlwaysFalse = 464,
	WRN_FinalizeMethod = 465,
	ERR_ExplicitImplParams = 466,
X	// WRN_AmbigLookupMeth = 467, //no longer issued in Roslyn
	//ERR_SameFullNameThisAggThisAgg = 468, no longer used in Roslyn
	WRN_GotoCaseShouldConvert = 469,
	ERR_MethodImplementingAccessor = 470,
	//ERR_TypeArgsNotAllowedAmbig = 471, no longer issued in Roslyn
	WRN_NubExprIsConstBool = 472,
	WRN_ExplicitImplCollision = 473,
	// unused 474-499
	ERR_AbstractHasBody = 500,
	ERR_ConcreteMissingBody = 501,
	ERR_AbstractAndSealed = 502,
	ERR_AbstractNotVirtual = 503,
X	ERR_StaticConstant = 504,
	ERR_CantOverrideNonFunction = 505,
	ERR_CantOverrideNonVirtual = 506,
X	ERR_CantChangeAccessOnOverride = 507,
	ERR_CantChangeReturnTypeOnOverride = 508,
	ERR_CantDeriveFromSealedType = 509,
	ERR_AbstractInConcreteClass = 513,
	ERR_StaticConstructorWithExplicitConstructorCall = 514,
	ERR_StaticConstructorWithAccessModifiers = 515,
	ERR_RecursiveConstructorCall = 516,
	ERR_ObjectCallingBaseConstructor = 517,
X	ERR_PredefinedTypeNotFound = 518,
	//ERR_PredefinedTypeBadType = 520,
	ERR_StructWithBaseConstructorCall = 522,
X	ERR_StructLayoutCycle = 523,
	ERR_InterfacesCannotContainTypes = 524,
	ERR_InterfacesCantContainFields = 525,
	ERR_InterfacesCantContainConstructors = 526,
	ERR_NonInterfaceInInterfaceList = 527,
	ERR_DuplicateInterfaceInBaseList = 528,
	ERR_CycleInInterfaceInheritance = 529,
	ERR_InterfaceMemberHasBody = 531,
	ERR_HidingAbstractMethod = 533,
	ERR_UnimplementedAbstractMethod = 534,
	ERR_UnimplementedInterfaceMember = 535,
	ERR_ObjectCantHaveBases = 537,
	ERR_ExplicitInterfaceImplementationNotInterface = 538,
	ERR_InterfaceMemberNotFound = 539,
	ERR_ClassDoesntImplementInterface = 540,
	ERR_ExplicitInterfaceImplementationInNonClassOrStruct = 541,
	ERR_MemberNameSameAsType = 542,
	ERR_EnumeratorOverflow = 543,
	ERR_CantOverrideNonProperty = 544,
X	ERR_NoGetToOverride = 545,
	ERR_NoSetToOverride = 546,
	ERR_PropertyCantHaveVoidType = 547,
	ERR_PropertyWithNoAccessors = 548,
	ERR_NewVirtualInSealed = 549,
	ERR_ExplicitPropertyAddingAccessor = 550,
	ERR_ExplicitPropertyMissingAccessor = 551,
X	ERR_ConversionWithInterface = 552,
	ERR_ConversionWithBase = 553,
	ERR_ConversionWithDerived = 554,
	ERR_IdentityConversion = 555,
	ERR_ConversionNotInvolvingContainedType = 556,
	ERR_DuplicateConversionInClass = 557,
	ERR_OperatorsMustBeStatic = 558,
	ERR_BadIncDecSignature = 559,
	ERR_BadUnaryOperatorSignature = 562,
X	ERR_BadBinaryOperatorSignature = 563,
	ERR_BadShiftOperatorSignature = 564,
	ERR_InterfacesCantContainOperators = 567,
	ERR_StructsCantContainDefaultConstructor = 568,
	ERR_CantOverrideBogusMethod = 569,
X	ERR_BindToBogus = 570,
X	ERR_CantCallSpecialMethod = 571,
	ERR_BadTypeReference = 572,
	ERR_FieldInitializerInStruct = 573,
	ERR_BadDestructorName = 574,
	ERR_OnlyClassesCanContainDestructors = 575,
	ERR_ConflictAliasAndMember = 576,
	ERR_ConditionalOnSpecialMethod = 577,
	ERR_ConditionalMustReturnVoid = 578,
X	ERR_DuplicateAttribute = 579,
	ERR_ConditionalOnInterfaceMethod = 582,
	//ERR_ICE_Culprit = 583, No ICE in Roslyn. All of these are unused
	//ERR_ICE_Symbol = 584,
	//ERR_ICE_Node = 585,
	//ERR_ICE_File = 586,
	//ERR_ICE_Stage = 587,
	//ERR_ICE_Lexer = 588,
	//ERR_ICE_Parser = 589,
	ERR_OperatorCantReturnVoid = 590,
	ERR_InvalidAttributeArgument = 591,
X	ERR_AttributeOnBadSymbolType = 592,
	ERR_FloatOverflow = 594,
	ERR_InvalidReal = 595,
	ERR_ComImportWithoutUuidAttribute = 596,
	ERR_InvalidNamedArgument = 599,
	ERR_DllImportOnInvalidMethod = 601,
	// WRN_FeatureDeprecated = 602, // This error code is unused.
	// ERR_NameAttributeOnOverride = 609, // removed in Roslyn
	ERR_FieldCantBeRefAny = 610,
	ERR_ArrayElementCantBeRefAny = 611,
	WRN_DeprecatedSymbol = 612,
X	ERR_NotAnAttributeClass = 616,
	ERR_BadNamedAttributeArgument = 617,
X	WRN_DeprecatedSymbolStr = 618,
	ERR_DeprecatedSymbolStr = 619,
	ERR_IndexerCantHaveVoidType = 620,
	ERR_VirtualPrivate = 621,
	ERR_ArrayInitToNonArrayType = 622,
	ERR_ArrayInitInBadPlace = 623,
	ERR_MissingStructOffset = 625,
	WRN_ExternMethodNoImplementation = 626,
	WRN_ProtectedInSealed = 628,
	ERR_InterfaceImplementedByConditional = 629,
	ERR_InterfaceImplementedImplicitlyByVariadic = 630,
	ERR_IllegalRefParam = 631,
	ERR_BadArgumentToAttribute = 633,
	//ERR_MissingComTypeOrMarshaller = 635,
	ERR_StructOffsetOnBadStruct = 636,
	ERR_StructOffsetOnBadField = 637,
	ERR_AttributeUsageOnNonAttributeClass = 641,
	WRN_PossibleMistakenNullStatement = 642,
	ERR_DuplicateNamedAttributeArgument = 643,
	ERR_DeriveFromEnumOrValueType = 644,
	//ERR_IdentifierTooLong = 645, //not used in Roslyn. See ERR_MetadataNameTooLong
	ERR_DefaultMemberOnIndexedType = 646,
	//ERR_CustomAttributeError = 647,
	ERR_BogusType = 648,
	WRN_UnassignedInternalField = 649,
X	ERR_CStyleArray = 650,
	WRN_VacuousIntegralComp = 652,
	ERR_AbstractAttributeClass = 653,
	ERR_BadNamedAttributeArgumentType = 655,
	ERR_MissingPredefinedMember = 656,
	WRN_AttributeLocationOnBadDeclaration = 657,
	WRN_InvalidAttributeLocation = 658,
	WRN_EqualsWithoutGetHashCode = 659,
	WRN_EqualityOpWithoutEquals = 660,
	WRN_EqualityOpWithoutGetHashCode = 661,
	ERR_OutAttrOnRefParam = 662,
	ERR_OverloadRefKind = 663,
	ERR_LiteralDoubleCast = 664,
	WRN_IncorrectBooleanAssg = 665,
	ERR_ProtectedInStruct = 666,
	//ERR_FeatureDeprecated = 667,
	ERR_InconsistentIndexerNames = 668, // Named 'ERR_InconsistantIndexerNames' in native compiler
	ERR_ComImportWithUserCtor = 669,
	ERR_FieldCantHaveVoidType = 670,
	WRN_NonObsoleteOverridingObsolete = 672,
	ERR_SystemVoid = 673,
	ERR_ExplicitParamArray = 674,
X	WRN_BitwiseOrSignExtend = 675,
	ERR_VolatileStruct = 677,
	ERR_VolatileAndReadonly = 678,
	// WRN_OldWarning_ProtectedInternal = 679, // This error code is unused.
	// WRN_OldWarning_AccessibleReadonly = 680, // This error code is unused.
	ERR_AbstractField = 681,
	ERR_BogusExplicitImpl = 682,
	ERR_ExplicitMethodImplAccessor = 683,
	WRN_CoClassWithoutComImport = 684,
	ERR_ConditionalWithOutParam = 685,
X	ERR_AccessorImplementingMethod = 686,
	ERR_AliasQualAsExpression = 687,
	ERR_DerivingFromATyVar = 689,
	//FTL_MalformedMetadata = 690,
	ERR_DuplicateTypeParameter = 692,
	WRN_TypeParameterSameAsOuterTypeParameter = 693,
	ERR_TypeVariableSameAsParent = 694,
	ERR_UnifyingInterfaceInstantiations = 695,
	ERR_GenericDerivingFromAttribute = 698,
	ERR_TyVarNotFoundInConstraint = 699,
	ERR_BadBoundType = 701,
X	ERR_SpecialTypeAsBound = 702,
X	ERR_BadVisBound = 703,
	ERR_LookupInTypeVariable = 704,
	ERR_BadConstraintType = 706,
	ERR_InstanceMemberInStaticClass = 708,
	ERR_StaticBaseClass = 709,
	ERR_ConstructorInStaticClass = 710,
	ERR_DestructorInStaticClass = 711,
	ERR_InstantiatingStaticClass = 712,
	ERR_StaticDerivedFromNonObject = 713,
	ERR_StaticClassInterfaceImpl = 714,
	ERR_OperatorInStaticClass = 715,
	ERR_ConvertToStaticClass = 716,
	ERR_ConstraintIsStaticClass = 717,
	ERR_GenericArgIsStaticClass = 718,
	ERR_ArrayOfStaticClass = 719,
	ERR_IndexerInStaticClass = 720,
	ERR_ParameterIsStaticClass = 721,
	ERR_ReturnTypeIsStaticClass = 722,
	ERR_VarDeclIsStaticClass = 723,
	ERR_BadEmptyThrowInFinally = 724,
	//ERR_InvalidDecl = 725,
	ERR_InvalidSpecifier = 726,
	//ERR_InvalidSpecifierUnk = 727,
	WRN_AssignmentToLockOrDispose = 728,
	ERR_ForwardedTypeInThisAssembly = 729,
	ERR_ForwardedTypeIsNested = 730,
X	ERR_CycleInTypeForwarder = 731,
	//ERR_FwdedGeneric = 733,
	ERR_AssemblyNameOnNonModule = 734,
	ERR_InvalidFwdType = 735,
	ERR_CloseUnimplementedInterfaceMemberStatic = 736,
	ERR_CloseUnimplementedInterfaceMemberNotPublic = 737,
	ERR_CloseUnimplementedInterfaceMemberWrongReturnType = 738,
	ERR_DuplicateTypeForwarder = 739,
	ERR_ExpectedSelectOrGroup = 742,
	ERR_ExpectedContextualKeywordOn = 743,
	ERR_ExpectedContextualKeywordEquals = 744,
	ERR_ExpectedContextualKeywordBy = 745,
	ERR_InvalidAnonymousTypeMemberDeclarator = 746,
	ERR_InvalidInitializerElementInitializer = 747,
	ERR_InconsistentLambdaParameterUsage = 748,
	ERR_PartialMethodInvalidModifier = 750,
	ERR_PartialMethodOnlyInPartialClass = 751,
	ERR_PartialMethodCannotHaveOutParameters = 752,
	// ERR_PartialMethodOnlyMethods = 753, Removed as it is subsumed by ERR_PartialMisplaced
	ERR_PartialMethodNotExplicit = 754,
	ERR_PartialMethodExtensionDifference = 755,
	ERR_PartialMethodOnlyOneLatent = 756,
	ERR_PartialMethodOnlyOneActual = 757,
	ERR_PartialMethodParamsDifference = 758,
	ERR_PartialMethodMustHaveLatent = 759,
	ERR_PartialMethodInconsistentConstraints = 761,
	ERR_PartialMethodToDelegate = 762,
	ERR_PartialMethodStaticDifference = 763,
	ERR_PartialMethodUnsafeDifference = 764,
	ERR_PartialMethodInExpressionTree = 765,
	ERR_PartialMethodMustReturnVoid = 766,
	ERR_ExplicitImplCollisionOnRefOut = 767,
	ERR_IndirectRecursiveConstructorCall = 768,
	// unused 769-799
	//ERR_NoEmptyArrayRanges = 800,
	//ERR_IntegerSpecifierOnOneDimArrays = 801,
	//ERR_IntegerSpecifierMustBePositive = 802,
	//ERR_ArrayRangeDimensionsMustMatch = 803,
	//ERR_ArrayRangeDimensionsWrong = 804,
	//ERR_IntegerSpecifierValidOnlyOnArrays = 805,
	//ERR_ArrayRangeSpecifierValidOnlyOnArrays = 806,
	//ERR_UseAdditionalSquareBrackets = 807,
	//ERR_DotDotNotAssociative = 808,
	WRN_ObsoleteOverridingNonObsolete = 809,
	WRN_DebugFullNameTooLong = 811, // Dev11 name: ERR_DebugFullNameTooLong
	ERR_ImplicitlyTypedVariableAssignedBadValue = 815, // Dev10 name: ERR_ImplicitlyTypedLocalAssignedBadValue
	ERR_ImplicitlyTypedVariableWithNoInitializer = 818, // Dev10 name: ERR_ImplicitlyTypedLocalWithNoInitializer
	ERR_ImplicitlyTypedVariableMultipleDeclarator = 819, // Dev10 name: ERR_ImplicitlyTypedLocalMultipleDeclarator
	ERR_ImplicitlyTypedVariableAssignedArrayInitializer = 820, // Dev10 name: ERR_ImplicitlyTypedLocalAssignedArrayInitializer
	ERR_ImplicitlyTypedLocalCannotBeFixed = 821,
	ERR_ImplicitlyTypedVariableCannotBeConst = 822, // Dev10 name: ERR_ImplicitlyTypedLocalCannotBeConst
	WRN_ExternCtorNoImplementation = 824,
	ERR_TypeVarNotFound = 825,
X	ERR_ImplicitlyTypedArrayNoBestType = 826,
	ERR_AnonymousTypePropertyAssignedBadValue = 828,
	ERR_ExpressionTreeContainsBaseAccess = 831,
	ERR_ExpressionTreeContainsAssignment = 832,
	ERR_AnonymousTypeDuplicatePropertyName = 833,
X	ERR_StatementLambdaToExpressionTree = 834,
	ERR_ExpressionTreeMustHaveDelegate = 835,
	ERR_AnonymousTypeNotAvailable = 836,
	ERR_LambdaInIsAs = 837,
	ERR_ExpressionTreeContainsMultiDimensionalArrayInitializer = 838,
	ERR_MissingArgument = 839,
X	//ERR_AutoPropertiesMustHaveBothAccessors = 840,
	ERR_VariableUsedBeforeDeclaration = 841,
	//ERR_ExplicitLayoutAndAutoImplementedProperty = 842,
	ERR_UnassignedThisAutoProperty = 843,
	ERR_VariableUsedBeforeDeclarationAndHidesField = 844,
X	ERR_ExpressionTreeContainsBadCoalesce = 845,
	ERR_ArrayInitializerExpected = 846,
	ERR_ArrayInitializerIncorrectLength = 847,
	// ERR_OverloadRefOutCtor = 851, Replaced By ERR_OverloadRefKind
	ERR_ExpressionTreeContainsNamedArgument = 853,
	ERR_ExpressionTreeContainsOptionalArgument = 854,
	ERR_ExpressionTreeContainsIndexedProperty = 855,
	ERR_IndexedPropertyRequiresParams = 856,
	ERR_IndexedPropertyMustHaveAllOptionalParams = 857,
	//ERR_FusionConfigFileNameTooLong = 858, unused in Roslyn. We give ERR_CantReadConfigFile now.
	// unused 859-1000
X	ERR_IdentifierExpected = 1001,
	ERR_SemicolonExpected = 1002,
	ERR_SyntaxError = 1003,
	ERR_DuplicateModifier = 1004,
	ERR_DuplicateAccessor = 1007,
	ERR_IntegralTypeExpected = 1008,
X	ERR_IllegalEscape = 1009,
	ERR_NewlineInConst = 1010,
	ERR_EmptyCharConst = 1011,
	ERR_TooManyCharsInConst = 1012,
	ERR_InvalidNumber = 1013,
	ERR_GetOrSetExpected = 1014,
	ERR_ClassTypeExpected = 1015,
	ERR_NamedArgumentExpected = 1016,
	ERR_TooManyCatches = 1017,
X	ERR_ThisOrBaseExpected = 1018,
X	ERR_OvlUnaryOperatorExpected = 1019,
	ERR_OvlBinaryOperatorExpected = 1020,
	ERR_IntOverflow = 1021,
	ERR_EOFExpected = 1022,
	ERR_BadEmbeddedStmt = 1023,
	ERR_PPDirectiveExpected = 1024,
	ERR_EndOfPPLineExpected = 1025,
X	ERR_CloseParenExpected = 1026,
	ERR_EndifDirectiveExpected = 1027,
	ERR_UnexpectedDirective = 1028,
X	ERR_ErrorDirective = 1029,
	WRN_WarningDirective = 1030,
	ERR_TypeExpected = 1031,
	ERR_PPDefFollowsToken = 1032,
	//ERR_TooManyLines = 1033, unused in Roslyn.
	//ERR_LineTooLong = 1034, unused in Roslyn.
	ERR_OpenEndedComment = 1035,
	ERR_OvlOperatorExpected = 1037,
	ERR_EndRegionDirectiveExpected = 1038,
	ERR_UnterminatedStringLit = 1039,
	ERR_BadDirectivePlacement = 1040,
	ERR_IdentifierExpectedKW = 1041,
	ERR_SemiOrLBraceExpected = 1043,
	ERR_MultiTypeInDeclaration = 1044,
	ERR_AddOrRemoveExpected = 1055,
	ERR_UnexpectedCharacter = 1056,
	ERR_ProtectedInStatic = 1057,
	WRN_UnreachableGeneralCatch = 1058,
X	ERR_IncrementLvalueExpected = 1059,
X	// WRN_UninitializedField = 1060, // unused in Roslyn.
X	ERR_NoSuchMemberOrExtension = 1061,
	WRN_DeprecatedCollectionInitAddStr = 1062,
	ERR_DeprecatedCollectionInitAddStr = 1063,
	WRN_DeprecatedCollectionInitAdd = 1064,
	ERR_DefaultValueNotAllowed = 1065,
	WRN_DefaultValueForUnconsumedLocation = 1066,
	ERR_PartialWrongTypeParamsVariance = 1067,
	ERR_GlobalSingleTypeNameNotFoundFwd = 1068,
	ERR_DottedTypeNameNotFoundInNSFwd = 1069,
	ERR_SingleTypeNameNotFoundFwd = 1070,
	//ERR_NoSuchMemberOnNoPIAType = 1071, //EE
	WRN_IdentifierOrNumericLiteralExpected = 1072,
	ERR_UnexpectedToken = 1073,
	// unused 1074-1098
	// ERR_EOLExpected = 1099, // EE
	// ERR_NotSupportedinEE = 1100, // EE
	ERR_BadThisParam = 1100,
	// ERR_BadRefWithThis = 1101, replaced by ERR_BadParameterModifiers
	// ERR_BadOutWithThis = 1102, replaced by ERR_BadParameterModifiers
	ERR_BadTypeforThis = 1103,
	ERR_BadParamModThis = 1104,
	ERR_BadExtensionMeth = 1105,
	ERR_BadExtensionAgg = 1106,
	ERR_DupParamMod = 1107,
	// ERR_MultiParamMod = 1108, replaced by ERR_BadParameterModifiers
	ERR_ExtensionMethodsDecl = 1109,
	ERR_ExtensionAttrNotFound = 1110,
	//ERR_ExtensionTypeParam = 1111,
X	ERR_ExplicitExtension = 1112,
	ERR_ValueTypeExtDelegate = 1113,
	// unused 1114-1199
	// Below five error codes are unused.
	// WRN_FeatureDeprecated2 = 1200,
	// WRN_FeatureDeprecated3 = 1201,
	// WRN_FeatureDeprecated4 = 1202,
	// WRN_FeatureDeprecated5 = 1203,
	// WRN_OldWarning_FeatureDefaultDeprecated = 1204,
	// unused 1205-1500
X	ERR_BadArgCount = 1501,
X	//ERR_BadArgTypes = 1502,
	ERR_BadArgType = 1503,
	ERR_NoSourceFile = 1504,
	ERR_CantRefResource = 1507,
	ERR_ResourceNotUnique = 1508,
	ERR_ImportNonAssembly = 1509,
	ERR_RefLvalueExpected = 1510,
	ERR_BaseInStaticMeth = 1511,
	ERR_BaseInBadContext = 1512,
	ERR_RbraceExpected = 1513,
	ERR_LbraceExpected = 1514,
	ERR_InExpected = 1515,
	ERR_InvalidPreprocExpr = 1517,
	//ERR_BadTokenInType = 1518, unused in Roslyn
X	ERR_InvalidMemberDecl = 1519,
	ERR_MemberNeedsType = 1520,
	ERR_BadBaseType = 1521,
	WRN_EmptySwitch = 1522,
	ERR_ExpectedEndTry = 1524,
	ERR_InvalidExprTerm = 1525,
	ERR_BadNewExpr = 1526,
	ERR_NoNamespacePrivate = 1527,
	ERR_BadVarDecl = 1528,
	ERR_UsingAfterElements = 1529,
	//ERR_NoNewOnNamespaceElement = 1530, EDMAURER we now give BadMemberFlag which is only a little less specific than this.
	//ERR_DontUseInvoke = 1533,
	ERR_BadBinOpArgs = 1534,
	ERR_BadUnOpArgs = 1535,
	ERR_NoVoidParameter = 1536,
	ERR_DuplicateAlias = 1537,
X	ERR_BadProtectedAccess = 1540,
	//ERR_CantIncludeDirectory = 1541,
	ERR_AddModuleAssembly = 1542,
	ERR_BindToBogusProp2 = 1545,
X	ERR_BindToBogusProp1 = 1546,
	ERR_NoVoidHere = 1547,
X	//ERR_CryptoFailed = 1548,
	//ERR_CryptoNotFound = 1549,
	ERR_IndexerNeedsParam = 1551,
	ERR_BadArraySyntax = 1552,
	ERR_BadOperatorSyntax = 1553,
	//ERR_BadOperatorSyntax2 = 1554, Not used in Roslyn.
	ERR_MainClassNotFound = 1555,
	ERR_MainClassNotClass = 1556,
	//ERR_MainClassWrongFile = 1557, Not used in Roslyn. This was used only when compiling and producing two outputs.
	ERR_NoMainInClass = 1558,
	//ERR_MainClassIsImport = 1559, Not used in Roslyn. Scenario occurs so infrequently that it is not worth re-implementing.
	//ERR_FileNameTooLong = 1560,
	//ERR_OutputFileNameTooLong = 1561, Not used in Roslyn. We report a more generic error that doesn't mention "output file" but is fine.
	ERR_OutputNeedsName = 1562,
	//ERR_OutputNeedsInput = 1563,
X	ERR_CantHaveWin32ResAndManifest = 1564,
	ERR_CantHaveWin32ResAndIcon = 1565,
	ERR_CantReadResource = 1566,
X	//ERR_AutoResGen = 1567,
	ERR_DocFileGen = 1569,
	WRN_XMLParseError = 1570,
	WRN_DuplicateParamTag = 1571,
	WRN_UnmatchedParamTag = 1572,
	WRN_MissingParamTag = 1573,
	WRN_BadXMLRef = 1574,
	ERR_BadStackAllocExpr = 1575,
	ERR_InvalidLineNumber = 1576,
	//ERR_ALinkFailed = 1577, No alink usage in Roslyn
	ERR_MissingPPFile = 1578,
X	ERR_ForEachMissingMember = 1579,
	WRN_BadXMLRefParamType = 1580,
	WRN_BadXMLRefReturnType = 1581,
	ERR_BadWin32Res = 1583,
	WRN_BadXMLRefSyntax = 1584,
	ERR_BadModifierLocation = 1585,
	ERR_MissingArraySize = 1586,
	WRN_UnprocessedXMLComment = 1587,
	//ERR_CantGetCORSystemDir = 1588,
	WRN_FailedInclude = 1589,
	WRN_InvalidInclude = 1590,
X	WRN_MissingXMLComment = 1591,
	WRN_XMLParseIncludeError = 1592,
	ERR_BadDelArgCount = 1593,
	//ERR_BadDelArgTypes = 1594,
	// WRN_OldWarning_MultipleTypeDefs = 1595, // This error code is unused.
	// WRN_OldWarning_DocFileGenAndIncr = 1596, // This error code is unused.
	ERR_UnexpectedSemicolon = 1597,
X	// WRN_XMLParserNotFound = 1598, // No longer used (though, conceivably, we could report it if Linq to Xml is missing at compile time).
	ERR_MethodReturnCantBeRefAny = 1599,
	ERR_CompileCancelled = 1600,
	ERR_MethodArgCantBeRefAny = 1601,
	ERR_AssgReadonlyLocal = 1604,
	ERR_RefReadonlyLocal = 1605,
	//ERR_ALinkCloseFailed = 1606,
X	WRN_ALinkWarn = 1607,
	ERR_CantUseRequiredAttribute = 1608,
	ERR_NoModifiersOnAccessor = 1609,
X	// WRN_DeleteAutoResFailed = 1610, // Unused.
	ERR_ParamsCantBeWithModifier = 1611,
X	ERR_ReturnNotLValue = 1612,
	ERR_MissingCoClass = 1613,
X	ERR_AmbiguousAttribute = 1614,
	ERR_BadArgExtraRef = 1615,
X	WRN_CmdOptionConflictsSource = 1616,
	ERR_BadCompatMode = 1617,
	ERR_DelegateOnConditional = 1618,
	ERR_CantMakeTempFile = 1619, //changed to now accept only one argument
	ERR_BadArgRef = 1620,
	ERR_YieldInAnonMeth = 1621,
	ERR_ReturnInIterator = 1622,
	ERR_BadIteratorArgType = 1623,
	ERR_BadIteratorReturn = 1624,
	ERR_BadYieldInFinally = 1625,
	ERR_BadYieldInTryOfCatch = 1626,
	ERR_EmptyYield = 1627,
	ERR_AnonDelegateCantUse = 1628,
	ERR_IllegalInnerUnsafe = 1629,
	//ERR_BadWatsonMode = 1630,
	ERR_BadYieldInCatch = 1631,
	ERR_BadDelegateLeave = 1632,
	WRN_IllegalPragma = 1633,
	WRN_IllegalPPWarning = 1634,
	WRN_BadRestoreNumber = 1635,
	ERR_VarargsIterator = 1636,
	ERR_UnsafeIteratorArgType = 1637,
	//ERR_ReservedIdentifier = 1638,
	ERR_BadCoClassSig = 1639,
X	ERR_MultipleIEnumOfT = 1640,
	ERR_FixedDimsRequired = 1641,
	ERR_FixedNotInStruct = 1642,
	ERR_AnonymousReturnExpected = 1643,
X	//ERR_NonECMAFeature = 1644,
	WRN_NonECMAFeature = 1645,
	ERR_ExpectedVerbatimLiteral = 1646,
	//FTL_StackOverflow = 1647,
	ERR_AssgReadonly2 = 1648,
	ERR_RefReadonly2 = 1649,
	ERR_AssgReadonlyStatic2 = 1650,
	ERR_RefReadonlyStatic2 = 1651,
	ERR_AssgReadonlyLocal2Cause = 1654,
	ERR_RefReadonlyLocal2Cause = 1655,
X	ERR_AssgReadonlyLocalCause = 1656,
	ERR_RefReadonlyLocalCause = 1657,
X	WRN_ErrorOverride = 1658,
	// WRN_OldWarning_ReservedIdentifier = 1659, // This error code is unused.
	ERR_AnonMethToNonDel = 1660,
	ERR_CantConvAnonMethParams = 1661,
	ERR_CantConvAnonMethReturns = 1662,
	ERR_IllegalFixedType = 1663,
	ERR_FixedOverflow = 1664,
	ERR_InvalidFixedArraySize = 1665,
	ERR_FixedBufferNotFixed = 1666,
	ERR_AttributeNotOnAccessor = 1667,
	WRN_InvalidSearchPathDir = 1668,
	ERR_IllegalVarArgs = 1669,
	ERR_IllegalParams = 1670,
	ERR_BadModifiersOnNamespace = 1671,
	ERR_BadPlatformType = 1672,
	ERR_ThisStructNotInAnonMeth = 1673,
X	ERR_NoConvToIDisp = 1674,
	// ERR_InvalidGenericEnum = 1675, replaced with 7002
	ERR_BadParamRef = 1676,
	ERR_BadParamExtraRef = 1677,
	ERR_BadParamType = 1678, // Requires SymbolDistinguisher.
	ERR_BadExternIdentifier = 1679,
	ERR_AliasMissingFile = 1680,
	ERR_GlobalExternAlias = 1681,
	// WRN_MissingTypeNested = 1682, // unused in Roslyn.
	// In Roslyn, we generate errors ERR_MissingTypeInSource and ERR_MissingTypeInAssembly instead of warnings WRN_MissingTypeInSource and WRN_MissingTypeInAssembly respectively.
X	// WRN_MissingTypeInSource = 1683,
	// WRN_MissingTypeInAssembly = 1684,
X	WRN_MultiplePredefTypes = 1685,
	ERR_LocalCantBeFixedAndHoisted = 1686,
	WRN_TooManyLinesForDebugger = 1687,
	ERR_CantConvAnonMethNoParams = 1688,
	ERR_ConditionalOnNonAttributeClass = 1689,
X	WRN_CallOnNonAgileField = 1690,
X	// WRN_BadWarningNumber = 1691, // we no longer generate this warning for an unrecognized warning ID specified as an argument to /nowarn or /warnaserror.
	WRN_InvalidNumber = 1692,
	// WRN_FileNameTooLong = 1694, //unused.
	WRN_IllegalPPChecksum = 1695,
	WRN_EndOfPPLineExpected = 1696,
	WRN_ConflictingChecksum = 1697,
	// WRN_AssumedMatchThis = 1698, // This error code is unused.
X	// WRN_UseSwitchInsteadOfAttribute = 1699, // This error code is unused.
X	WRN_InvalidAssemblyName = 1700,
X	WRN_UnifyReferenceMajMin = 1701,
	WRN_UnifyReferenceBldRev = 1702,
X	ERR_DuplicateImport = 1703,
X	ERR_DuplicateImportSimple = 1704,
X	ERR_AssemblyMatchBadVersion = 1705,
	//ERR_AnonMethNotAllowed = 1706, Unused in Roslyn. Previously given when a lambda was supplied as an attribute argument.
	// WRN_DelegateNewMethBind = 1707, // This error code is unused.
X	ERR_FixedNeedsLvalue = 1708,
	// WRN_EmptyFileName = 1709, // This error code is unused.
	WRN_DuplicateTypeParamTag = 1710,
	WRN_UnmatchedTypeParamTag = 1711,
	WRN_MissingTypeParamTag = 1712,
	//FTL_TypeNameBuilderError = 1713,
	//ERR_ImportBadBase = 1714, // This error code is unused and replaced with ERR_NoTypeDef
	ERR_CantChangeTypeOnOverride = 1715,
X	ERR_DoNotUseFixedBufferAttr = 1716,
	WRN_AssignmentToSelf = 1717,
	WRN_ComparisonToSelf = 1718,
	ERR_CantOpenWin32Res = 1719,
	WRN_DotOnDefault = 1720,
X	ERR_NoMultipleInheritance = 1721,
	ERR_BaseClassMustBeFirst = 1722,
	WRN_BadXMLRefTypeVar = 1723,
	//ERR_InvalidDefaultCharSetValue = 1724, Not used in Roslyn.
	ERR_FriendAssemblyBadArgs = 1725,
X	ERR_FriendAssemblySNReq = 1726,
	//ERR_WatsonSendNotOptedIn = 1727, We're not doing any custom Watson processing in Roslyn. In modern OSs, Watson behavior is configured with machine policy settings.
	ERR_DelegateOnNullable = 1728,
X	ERR_BadCtorArgCount = 1729,
	ERR_GlobalAttributesNotFirst = 1730,
	//ERR_CantConvAnonMethReturnsNoDelegate = 1731, Not used in Roslyn. When there is no delegate, we reuse the message that contains a substitution string for the delegate type.
	//ERR_ParameterExpected = 1732, Not used in Roslyn.
	ERR_ExpressionExpected = 1733,
	WRN_UnmatchedParamRefTag = 1734,
	WRN_UnmatchedTypeParamRefTag = 1735,
	ERR_DefaultValueMustBeConstant = 1736,
	ERR_DefaultValueBeforeRequiredValue = 1737,
	ERR_NamedArgumentSpecificationBeforeFixedArgument = 1738,
	ERR_BadNamedArgument = 1739,
	ERR_DuplicateNamedArgument = 1740,
	ERR_RefOutDefaultValue = 1741,
	ERR_NamedArgumentForArray = 1742,
	ERR_DefaultValueForExtensionParameter = 1743,
	ERR_NamedArgumentUsedInPositional = 1744,
	ERR_DefaultValueUsedWithAttributes = 1745,
	ERR_BadNamedArgumentForDelegateInvoke = 1746,
	ERR_NoPIAAssemblyMissingAttribute = 1747,
	ERR_NoCanonicalView = 1748,
	//ERR_TypeNotFoundForNoPIA = 1749,
	ERR_NoConversionForDefaultParam = 1750,
	ERR_DefaultValueForParamsParameter = 1751,
	ERR_NewCoClassOnLink = 1752,
	ERR_NoPIANestedType = 1754,
	//ERR_InvalidTypeIdentifierConstructor = 1755,
	ERR_InteropTypeMissingAttribute = 1756,
	ERR_InteropStructContainsMethods = 1757,
	ERR_InteropTypesWithSameNameAndGuid = 1758,
	ERR_NoPIAAssemblyMissingAttributes = 1759,
	ERR_AssemblySpecifiedForLinkAndRef = 1760,
	ERR_LocalTypeNameClash = 1761,
X	WRN_ReferencedAssemblyReferencesLinkedPIA = 1762,
	ERR_NotNullRefDefaultParameter = 1763,
	ERR_FixedLocalInLambda = 1764,
	// WRN_TypeNotFoundForNoPIAWarning = 1765, // This error code is unused.
	ERR_MissingMethodOnSourceInterface = 1766,
	ERR_MissingSourceInterface = 1767,
	ERR_GenericsUsedInNoPIAType = 1768,
	ERR_GenericsUsedAcrossAssemblies = 1769,
	ERR_NoConversionForNubDefaultParam = 1770,
	//ERR_MemberWithGenericsUsedAcrossAssemblies = 1771,
	//ERR_GenericsUsedInBaseTypeAcrossAssemblies = 1772,
	ERR_InvalidSubsystemVersion = 1773,
	ERR_InteropMethodWithBody = 1774,
	// unused 1775-1899
	ERR_BadWarningLevel = 1900,
	ERR_BadDebugType = 1902,
	//ERR_UnknownTestSwitch = 1903,
	ERR_BadResourceVis = 1906,
	ERR_DefaultValueTypeMustMatch = 1908,
	//ERR_DefaultValueBadParamType = 1909, // Replaced by ERR_DefaultValueBadValueType in Roslyn.
	ERR_DefaultValueBadValueType = 1910,
	ERR_MemberAlreadyInitialized = 1912,
	ERR_MemberCannotBeInitialized = 1913,
	ERR_StaticMemberInObjectInitializer = 1914,
	ERR_ReadonlyValueTypeInObjectInitializer = 1917,
	ERR_ValueTypePropertyInObjectInitializer = 1918,
X	ERR_UnsafeTypeInObjectCreation = 1919,
	ERR_EmptyElementInitializer = 1920,
X	ERR_InitializerAddHasWrongSignature = 1921,
	ERR_CollectionInitRequiresIEnumerable = 1922,
	//ERR_InvalidCollectionInitializerType = 1925, unused in Roslyn. Occurs so infrequently in real usage that it is not worth reimplementing.
X	ERR_CantOpenWin32Manifest = 1926,
	WRN_CantHaveManifestForModule = 1927,
	//ERR_BadExtensionArgTypes = 1928, unused in Roslyn (replaced by ERR_BadInstanceArgType)
	ERR_BadInstanceArgType = 1929,
	ERR_QueryDuplicateRangeVariable = 1930,
	ERR_QueryRangeVariableOverrides = 1931,
	ERR_QueryRangeVariableAssignedBadValue = 1932,
X	//ERR_QueryNotAllowed = 1933, unused in Roslyn. This specific message is not necessary for correctness and adds little.
	ERR_QueryNoProviderCastable = 1934,
	ERR_QueryNoProviderStandard = 1935,
X	ERR_QueryNoProvider = 1936,
	ERR_QueryOuterKey = 1937,
	ERR_QueryInnerKey = 1938,
	ERR_QueryOutRefRangeVariable = 1939,
	ERR_QueryMultipleProviders = 1940,
X	ERR_QueryTypeInferenceFailedMulti = 1941,
X	ERR_QueryTypeInferenceFailed = 1942,
X	ERR_QueryTypeInferenceFailedSelectMany = 1943,
	ERR_ExpressionTreeContainsPointerOp = 1944,
	ERR_ExpressionTreeContainsAnonymousMethod = 1945,
X	ERR_AnonymousMethodToExpressionTree = 1946,
	ERR_QueryRangeVariableReadOnly = 1947,
	ERR_QueryRangeVariableSameAsTypeParam = 1948,
	ERR_TypeVarNotFoundRangeVariable = 1949,
	ERR_BadArgTypesForCollectionAdd = 1950,
	ERR_ByRefParameterInExpressionTree = 1951,
	ERR_VarArgsInExpressionTree = 1952,
	// ERR_MemGroupInExpressionTree = 1953, unused in Roslyn (replaced by ERR_LambdaInIsAs)
	ERR_InitializerAddHasParamModifiers = 1954,
	ERR_NonInvocableMemberCalled = 1955,
X	WRN_MultipleRuntimeImplementationMatches = 1956,
	WRN_MultipleRuntimeOverrideMatches = 1957,
	ERR_ObjectOrCollectionInitializerWithDelegateCreation = 1958,
	ERR_InvalidConstantDeclarationType = 1959,
	ERR_IllegalVarianceSyntax = 1960,
	ERR_UnexpectedVariance = 1961,
	ERR_BadDynamicTypeof = 1962,
	ERR_ExpressionTreeContainsDynamicOperation = 1963,
	ERR_BadDynamicConversion = 1964,
	ERR_DeriveFromDynamic = 1965,
	ERR_DeriveFromConstructedDynamic = 1966,
	ERR_DynamicTypeAsBound = 1967,
	ERR_ConstructedDynamicTypeAsBound = 1968,
	ERR_DynamicRequiredTypesMissing = 1969,
	ERR_ExplicitDynamicAttr = 1970,
	ERR_NoDynamicPhantomOnBase = 1971,
	ERR_NoDynamicPhantomOnBaseIndexer = 1972,
	ERR_BadArgTypeDynamicExtension = 1973,
	WRN_DynamicDispatchToConditionalMethod = 1974,
	ERR_NoDynamicPhantomOnBaseCtor = 1975,
	ERR_BadDynamicMethodArgMemgrp = 1976,
	ERR_BadDynamicMethodArgLambda = 1977,
	ERR_BadDynamicMethodArg = 1978,
	ERR_BadDynamicQuery = 1979,
	ERR_DynamicAttributeMissing = 1980,
	WRN_IsDynamicIsConfusing = 1981,
	//ERR_DynamicNotAllowedInAttribute = 1982, // Replaced by ERR_BadAttributeParamType in Roslyn.
	ERR_BadAsyncReturn = 1983,
	ERR_BadAwaitInFinally = 1984,
	ERR_BadAwaitInCatch = 1985,
	ERR_BadAwaitArg = 1986,
	ERR_BadAsyncArgType = 1988,
	ERR_BadAsyncExpressionTree = 1989,
	//ERR_WindowsRuntimeTypesMissing = 1990, // unused in Roslyn
	ERR_MixingWinRTEventWithRegular = 1991,
	ERR_BadAwaitWithoutAsync = 1992,
	//ERR_MissingAsyncTypes = 1993, // unused in Roslyn
	ERR_BadAsyncLacksBody = 1994,
	ERR_BadAwaitInQuery = 1995,
	ERR_BadAwaitInLock = 1996,
	ERR_TaskRetNoObjectRequired = 1997,
	WRN_AsyncLacksAwaits = 1998,
	ERR_FileNotFound = 2001,
	WRN_FileAlreadyIncluded = 2002,
	//ERR_DuplicateResponseFile = 2003,
	ERR_NoFileSpec = 2005,
	ERR_SwitchNeedsString = 2006,
	ERR_BadSwitch = 2007,
	WRN_NoSources = 2008,
	ERR_OpenResponseFile = 2011,
	ERR_CantOpenFileWrite = 2012,
	ERR_BadBaseNumber = 2013,
	// WRN_UseNewSwitch = 2014, //unused.
	ERR_BinaryFile = 2015,
	FTL_BadCodepage = 2016,
	ERR_NoMainOnDLL = 2017,
	//FTL_NoMessagesDLL = 2018,
	FTL_InvalidTarget = 2019,
	//ERR_BadTargetForSecondInputSet = 2020, Roslyn doesn't support building two binaries at once!
	FTL_InvalidInputFileName = 2021,
	//ERR_NoSourcesInLastInputSet = 2022, Roslyn doesn't support building two binaries at once!
	WRN_NoConfigNotOnCommandLine = 2023,
	ERR_InvalidFileAlignment = 2024,
	//ERR_NoDebugSwitchSourceMap = 2026, no sourcemap support in Roslyn.
	//ERR_SourceMapFileBinary = 2027,
	WRN_DefineIdentifierRequired = 2029,
	//ERR_InvalidSourceMap = 2030,
	//ERR_NoSourceMapFile = 2031,
X	//ERR_IllegalOptionChar = 2032,
	FTL_OutputFileExists = 2033,
	ERR_OneAliasPerReference = 2034,
	ERR_SwitchNeedsNumber = 2035,
	ERR_MissingDebugSwitch = 2036,
	ERR_ComRefCallInExpressionTree = 2037,
	WRN_BadUILang = 2038,
	ERR_InvalidFormatForGuidForOption = 2039,
	ERR_MissingGuidForOption = 2040,
	ERR_InvalidOutputName = 2041,
	ERR_InvalidDebugInformationFormat = 2042,
	ERR_LegacyObjectIdSyntax = 2043,
	ERR_SourceLinkRequiresPdb = 2044,
	ERR_CannotEmbedWithoutPdb = 2045,
	// unused 2046-2999
	WRN_CLS_NoVarArgs = 3000,
	WRN_CLS_BadArgType = 3001, // Requires SymbolDistinguisher.
	WRN_CLS_BadReturnType = 3002,
X	WRN_CLS_BadFieldPropType = 3003,
	// WRN_CLS_BadUnicode = 3004, //unused
	WRN_CLS_BadIdentifierCase = 3005,
	WRN_CLS_OverloadRefOut = 3006,
X	WRN_CLS_OverloadUnnamed = 3007,
	WRN_CLS_BadIdentifier = 3008,
X	WRN_CLS_BadBase = 3009,
	WRN_CLS_BadInterfaceMember = 3010,
	WRN_CLS_NoAbstractMembers = 3011,
	WRN_CLS_NotOnModules = 3012,
	WRN_CLS_ModuleMissingCLS = 3013,
	WRN_CLS_AssemblyNotCLS = 3014,
	WRN_CLS_BadAttributeType = 3015,
	WRN_CLS_ArrayArgumentToAttribute = 3016,
	WRN_CLS_NotOnModules2 = 3017,
	WRN_CLS_IllegalTrueInFalse = 3018,
	WRN_CLS_MeaninglessOnPrivateType = 3019,
	WRN_CLS_AssemblyNotCLS2 = 3021,
	WRN_CLS_MeaninglessOnParam = 3022,
	WRN_CLS_MeaninglessOnReturn = 3023,
	WRN_CLS_BadTypeVar = 3024,
	WRN_CLS_VolatileField = 3026,
	WRN_CLS_BadInterface = 3027,
	FTL_BadChecksumAlgorithm = 3028,
	#endregion diagnostics introduced in C# 4 and earlier
	// unused 3029-3999
	#region diagnostics introduced in C# 5
	// 4000 unused
	ERR_BadAwaitArgIntrinsic = 4001,
	// 4002 unused
	ERR_BadAwaitAsIdentifier = 4003,
	ERR_AwaitInUnsafeContext = 4004,
	ERR_UnsafeAsyncArgType = 4005,
	ERR_VarargsAsync = 4006,
	ERR_ByRefTypeAndAwait = 4007,
	ERR_BadAwaitArgVoidCall = 4008,
	ERR_NonTaskMainCantBeAsync = 4009,
	ERR_CantConvAsyncAnonFuncReturns = 4010,
	ERR_BadAwaiterPattern = 4011,
	ERR_BadSpecialByRefLocal = 4012,
	ERR_SpecialByRefInLambda = 4013,
X	WRN_UnobservedAwaitableExpression = 4014,
	ERR_SynchronizedAsyncMethod = 4015,
	ERR_BadAsyncReturnExpression = 4016,
	ERR_NoConversionForCallerLineNumberParam = 4017,
	ERR_NoConversionForCallerFilePathParam = 4018,
	ERR_NoConversionForCallerMemberNameParam = 4019,
	ERR_BadCallerLineNumberParamWithoutDefaultValue = 4020,
	ERR_BadCallerFilePathParamWithoutDefaultValue = 4021,
	ERR_BadCallerMemberNameParamWithoutDefaultValue = 4022,
	ERR_BadPrefer32OnLib = 4023,
	WRN_CallerLineNumberParamForUnconsumedLocation = 4024,
	WRN_CallerFilePathParamForUnconsumedLocation = 4025,
	WRN_CallerMemberNameParamForUnconsumedLocation = 4026,
	ERR_DoesntImplementAwaitInterface = 4027,
	ERR_BadAwaitArg_NeedSystem = 4028,
	ERR_CantReturnVoid = 4029,
	ERR_SecurityCriticalOrSecuritySafeCriticalOnAsync = 4030,
	ERR_SecurityCriticalOrSecuritySafeCriticalOnAsyncInClassOrStruct = 4031,
	ERR_BadAwaitWithoutAsyncMethod = 4032,
	ERR_BadAwaitWithoutVoidAsyncMethod = 4033,
	ERR_BadAwaitWithoutAsyncLambda = 4034,
	// ERR_BadAwaitWithoutAsyncAnonMeth = 4035, Merged with ERR_BadAwaitWithoutAsyncLambda in Roslyn
	ERR_NoSuchMemberOrExtensionNeedUsing = 4036,
	#endregion diagnostics introduced in C# 5
	// unused 4037-4999
	#region diagnostics introduced in C# 6
	// WRN_UnknownOption = 5000, //unused in Roslyn
	ERR_NoEntryPoint = 5001,
	// huge gap here; available 5002-6999
	ERR_UnexpectedAliasedName = 7000,
	ERR_UnexpectedGenericName = 7002,
X	ERR_UnexpectedUnboundGenericName = 7003,
	ERR_GlobalStatement = 7006,
	ERR_BadUsingType = 7007,
	ERR_ReservedAssemblyName = 7008,
	ERR_PPReferenceFollowsToken = 7009,
	ERR_ExpectedPPFile = 7010,
	ERR_ReferenceDirectiveOnlyAllowedInScripts = 7011,
	ERR_NameNotInContextPossibleMissingReference = 7012,
	ERR_MetadataNameTooLong = 7013,
	ERR_AttributesNotAllowed = 7014,
	ERR_ExternAliasNotAllowed = 7015,
	ERR_ConflictingAliasAndDefinition = 7016,
	ERR_GlobalDefinitionOrStatementExpected = 7017,
	ERR_ExpectedSingleScript = 7018,
	ERR_RecursivelyTypedVariable = 7019,
	ERR_YieldNotAllowedInScript = 7020,
	ERR_NamespaceNotAllowedInScript = 7021,
	WRN_MainIgnored = 7022,
	ERR_StaticInAsOrIs = 7023,
	ERR_InvalidDelegateType = 7024,
	ERR_BadVisEventType = 7025,
	ERR_GlobalAttributesNotAllowed = 7026,
	ERR_PublicKeyFileFailure = 7027,
	ERR_PublicKeyContainerFailure = 7028,
	ERR_FriendRefSigningMismatch = 7029,
	ERR_CannotPassNullForFriendAssembly = 7030,
	ERR_SignButNoPrivateKey = 7032,
	WRN_DelaySignButNoKey = 7033,
	ERR_InvalidVersionFormat = 7034,
	WRN_InvalidVersionFormat = 7035,
	ERR_NoCorrespondingArgument = 7036,
	// Moot: WRN_DestructorIsNotFinalizer = 7037,
	ERR_ModuleEmitFailure = 7038,
	// ERR_NameIllegallyOverrides2 = 7039, // Not used anymore due to 'Single Meaning' relaxation changes
	// ERR_NameIllegallyOverrides3 = 7040, // Not used anymore due to 'Single Meaning' relaxation changes
	ERR_ResourceFileNameNotUnique = 7041,
	ERR_DllImportOnGenericMethod = 7042,
	ERR_EncUpdateFailedMissingAttribute = 7043,
	ERR_ParameterNotValidForType = 7045,
	ERR_AttributeParameterRequired1 = 7046,
	ERR_AttributeParameterRequired2 = 7047,
	ERR_SecurityAttributeMissingAction = 7048,
	ERR_SecurityAttributeInvalidAction = 7049,
	ERR_SecurityAttributeInvalidActionAssembly = 7050,
	ERR_SecurityAttributeInvalidActionTypeOrMethod = 7051,
	ERR_PrincipalPermissionInvalidAction = 7052,
	ERR_FeatureNotValidInExpressionTree = 7053,
	ERR_MarshalUnmanagedTypeNotValidForFields = 7054,
	ERR_MarshalUnmanagedTypeOnlyValidForFields = 7055,
	ERR_PermissionSetAttributeInvalidFile = 7056,
	ERR_PermissionSetAttributeFileReadError = 7057,
	ERR_InvalidVersionFormat2 = 7058,
	ERR_InvalidAssemblyCultureForExe = 7059,
	//ERR_AsyncBeforeVersionFive = 7060,
	ERR_DuplicateAttributeInNetModule = 7061,
	//WRN_PDBConstantStringValueTooLong = 7063, gave up on this warning
	ERR_CantOpenIcon = 7064,
	ERR_ErrorBuildingWin32Resources = 7065,
	ERR_IteratorInInteractive = 7066,
	ERR_BadAttributeParamDefaultArgument = 7067,
	ERR_MissingTypeInSource = 7068,
	ERR_MissingTypeInAssembly = 7069,
	ERR_SecurityAttributeInvalidTarget = 7070,
	ERR_InvalidAssemblyName = 7071,
	//ERR_PartialTypesBeforeVersionTwo = 7072,
	//ERR_PartialMethodsBeforeVersionThree = 7073,
	//ERR_QueryBeforeVersionThree = 7074,
	//ERR_AnonymousTypeBeforeVersionThree = 7075,
	//ERR_ImplicitArrayBeforeVersionThree = 7076,
	//ERR_ObjectInitializerBeforeVersionThree = 7077,
	//ERR_LambdaBeforeVersionThree = 7078,
	ERR_NoTypeDefFromModule = 7079,
	WRN_CallerFilePathPreferredOverCallerMemberName = 7080,
	WRN_CallerLineNumberPreferredOverCallerMemberName = 7081,
	WRN_CallerLineNumberPreferredOverCallerFilePath = 7082,
	ERR_InvalidDynamicCondition = 7083,
	ERR_WinRtEventPassedByRef = 7084,
	ERR_ByRefReturnUnsupported = 7085,
	ERR_NetModuleNameMismatch = 7086,
	ERR_BadModuleName = 7087,
	ERR_BadCompilationOptionValue = 7088,
	ERR_BadAppConfigPath = 7089,
	WRN_AssemblyAttributeFromModuleIsOverridden = 7090,
	ERR_CmdOptionConflictsSource = 7091,
	ERR_FixedBufferTooManyDimensions = 7092,
	ERR_CantReadConfigFile = 7093,
	ERR_BadAwaitInCatchFilter = 7094,
	WRN_FilterIsConstantTrue = 7095,
	ERR_EncNoPIAReference = 7096,
	//ERR_EncNoDynamicOperation = 7097, // dynamic operations are now allowed
	ERR_LinkedNetmoduleMetadataMustProvideFullPEImage = 7098,
	ERR_MetadataReferencesNotSupported = 7099,
	ERR_InvalidAssemblyCulture = 7100,
	ERR_EncReferenceToAddedMember = 7101,
	ERR_MutuallyExclusiveOptions = 7102,
	ERR_InvalidDebugInfo = 7103,
	#endregion diagnostics introduced in C# 6
	// huge gap here; unused 7104-8000
	#region more diagnostics introduced in Roslyn (C# 6)
	WRN_UnimplementedCommandLineSwitch = 8001,
	WRN_ReferencedAssemblyDoesNotHaveStrongName = 8002,
	ERR_InvalidSignaturePublicKey = 8003,
	ERR_ExportedTypeConflictsWithDeclaration = 8004,
	ERR_ExportedTypesConflict = 8005,
	ERR_ForwardedTypeConflictsWithDeclaration = 8006,
	ERR_ForwardedTypesConflict = 8007,
	ERR_ForwardedTypeConflictsWithExportedType = 8008,
	WRN_RefCultureMismatch = 8009,
	ERR_AgnosticToMachineModule = 8010,
	ERR_ConflictingMachineModule = 8011,
	WRN_ConflictingMachineAssembly = 8012,
	ERR_CryptoHashFailed = 8013,
	ERR_MissingNetModuleReference = 8014,
	ERR_NetModuleNameMustBeUnique = 8015,
	ERR_UnsupportedTransparentIdentifierAccess = 8016,
	ERR_ParamDefaultValueDiffersFromAttribute = 8017,
	WRN_UnqualifiedNestedTypeInCref = 8018,
	HDN_UnusedUsingDirective = 8019,
	HDN_UnusedExternAlias = 8020,
	WRN_NoRuntimeMetadataVersion = 8021,
	ERR_FeatureNotAvailableInVersion1 = 8022, // Note: one per version to make telemetry easier
	ERR_FeatureNotAvailableInVersion2 = 8023,
	ERR_FeatureNotAvailableInVersion3 = 8024,
	ERR_FeatureNotAvailableInVersion4 = 8025,
	ERR_FeatureNotAvailableInVersion5 = 8026,
	// ERR_FeatureNotAvailableInVersion6 is below
	ERR_FieldHasMultipleDistinctConstantValues = 8027,
	ERR_ComImportWithInitializers = 8028,
	WRN_PdbLocalNameTooLong = 8029,
	ERR_RetNoObjectRequiredLambda = 8030,
	ERR_TaskRetNoObjectRequiredLambda = 8031,
	WRN_AnalyzerCannotBeCreated = 8032,
	WRN_NoAnalyzerInAssembly = 8033,
	WRN_UnableToLoadAnalyzer = 8034,
	ERR_CantReadRulesetFile = 8035,
	ERR_BadPdbData = 8036,
	// available 8037-8039
	INF_UnableToLoadSomeTypesInAnalyzer = 8040,
	// available 8041-8049
	ERR_InitializerOnNonAutoProperty = 8050,
	ERR_AutoPropertyMustHaveGetAccessor = 8051,
	ERR_AutoPropertyInitializerInInterface = 8052,
	ERR_EnumsCantContainDefaultConstructor = 8054,
	ERR_EncodinglessSyntaxTree = 8055,
	// ERR_AccessorListAndExpressionBody = 8056, Deprecated in favor of ERR_BlockBodyAndExpressionBody
	ERR_BlockBodyAndExpressionBody = 8057,
	//ERR_FeatureIsExperimental = 8058, No experimental feature
	ERR_FeatureNotAvailableInVersion6 = 8059,
	// available 8062-8069
	ERR_SwitchFallOut = 8070,
	// ERR_UnexpectedBoundGenericName = 8071, // for nameof - used in an early prototype
	ERR_NullPropagatingOpInExpressionTree = 8072,
	WRN_NubExprIsConstBool2 = 8073,
	ERR_DictionaryInitializerInExpressionTree = 8074,
	ERR_ExtensionCollectionElementInitializerInExpressionTree = 8075,
	ERR_UnclosedExpressionHole = 8076,
	ERR_SingleLineCommentInExpressionHole = 8077,
	ERR_InsufficientStack = 8078,
	ERR_UseDefViolationProperty = 8079,
	ERR_AutoPropertyMustOverrideSet = 8080,
	ERR_ExpressionHasNoName = 8081,
	ERR_SubexpressionNotInNameof = 8082,
	ERR_AliasQualifiedNameNotAnExpression = 8083,
	ERR_NameofMethodGroupWithTypeParameters = 8084,
	ERR_NoAliasHere = 8085,
	ERR_UnescapedCurly = 8086,
	ERR_EscapedCurly = 8087,
	ERR_TrailingWhitespaceInFormatSpecifier = 8088,
	ERR_EmptyFormatSpecifier = 8089,
	ERR_ErrorInReferencedAssembly = 8090,
	ERR_ExternHasConstructorInitializer = 8091,
	ERR_ExpressionOrDeclarationExpected = 8092,
	ERR_NameofExtensionMethod = 8093,
	WRN_AlignmentMagnitude = 8094,
	ERR_ConstantStringTooLong = 8095,
	ERR_DebugEntryPointNotSourceMethodDefinition = 8096,
	ERR_LoadDirectiveOnlyAllowedInScripts = 8097,
	ERR_PPLoadFollowsToken = 8098,
	ERR_SourceFileReferencesNotSupported = 8099,
	ERR_BadAwaitInStaticVariableInitializer = 8100,
	ERR_InvalidPathMap = 8101,
	ERR_PublicSignButNoKey = 8102,
	ERR_TooManyUserStrings = 8103,
	ERR_PeWritingFailure = 8104,
	#endregion diagnostics introduced in Roslyn (C# 6)
	#region diagnostics introduced in C# 6 updates
	WRN_AttributeIgnoredWhenPublicSigning = 8105,
	ERR_OptionMustBeAbsolutePath = 8106,
	#endregion diagnostics introduced in C# 6 updates
	ERR_FeatureNotAvailableInVersion7 = 8107,
	#region diagnostics for local functions introduced in C# 7
	ERR_DynamicLocalFunctionParamsParameter = 8108,
	ERR_ExpressionTreeContainsLocalFunction = 8110,
	#endregion diagnostics for local functions introduced in C# 7
	#region diagnostics for instrumentation
	ERR_InvalidInstrumentationKind = 8111,
	#endregion
	ERR_LocalFunctionMissingBody = 8112,
	ERR_InvalidHashAlgorithmName = 8113,
	// Available = 8113, 8114, 8115
	#region diagnostics for pattern-matching introduced in C# 7
	ERR_ThrowMisplaced = 8115,
	ERR_PatternNullableType = 8116,
	ERR_BadIsPatternExpression = 8117,
	ERR_SwitchExpressionValueExpected = 8119,
	ERR_PatternIsSubsumed = 8120,
	ERR_PatternWrongType = 8121,
	ERR_ExpressionTreeContainsIsMatch = 8122,
	#endregion diagnostics for pattern-matching introduced in C# 7
	#region tuple diagnostics introduced in C# 7
	WRN_TupleLiteralNameMismatch = 8123,
	ERR_TupleTooFewElements = 8124,
	ERR_TupleReservedElementName = 8125,
	ERR_TupleReservedElementNameAnyPosition = 8126,
	ERR_TupleDuplicateElementName = 8127,
	ERR_PredefinedTypeMemberNotFoundInAssembly = 8128,
	ERR_MissingDeconstruct = 8129,
	ERR_TypeInferenceFailedForImplicitlyTypedDeconstructionVariable = 8130,
	ERR_DeconstructRequiresExpression = 8131,
	ERR_DeconstructWrongCardinality = 8132,
	ERR_CannotDeconstructDynamic = 8133,
	ERR_DeconstructTooFewElements = 8134,
	ERR_ConversionNotTupleCompatible = 8135,
	ERR_DeconstructionVarFormDisallowsSpecificType = 8136,
	ERR_TupleElementNamesAttributeMissing = 8137,
	ERR_ExplicitTupleElementNamesAttribute = 8138,
	ERR_CantChangeTupleNamesOnOverride = 8139,
	ERR_DuplicateInterfaceWithTupleNamesInBaseList = 8140,
	ERR_ImplBadTupleNames = 8141,
	ERR_PartialMethodInconsistentTupleNames = 8142,
	ERR_ExpressionTreeContainsTupleLiteral = 8143,
	ERR_ExpressionTreeContainsTupleConversion = 8144,
	#endregion tuple diagnostics introduced in C# 7
	#region diagnostics for ref locals and ref returns introduced in C# 7
	ERR_AutoPropertyCannotBeRefReturning = 8145,
	ERR_RefPropertyMustHaveGetAccessor = 8146,
	ERR_RefPropertyCannotHaveSetAccessor = 8147,
	ERR_CantChangeRefReturnOnOverride = 8148,
	ERR_MustNotHaveRefReturn = 8149,
	ERR_MustHaveRefReturn = 8150,
	ERR_RefReturnMustHaveIdentityConversion = 8151,
	ERR_CloseUnimplementedInterfaceMemberWrongRefReturn = 8152,
	ERR_RefReturningCallInExpressionTree = 8153,
	ERR_BadIteratorReturnRef = 8154,
	ERR_BadRefReturnExpressionTree = 8155,
	ERR_RefReturnLvalueExpected = 8156,
	ERR_RefReturnNonreturnableLocal = 8157,
	ERR_RefReturnNonreturnableLocal2 = 8158,
	ERR_RefReturnRangeVariable = 8159,
	ERR_RefReturnReadonly = 8160,
	ERR_RefReturnReadonlyStatic = 8161,
	ERR_RefReturnReadonly2 = 8162,
	ERR_RefReturnReadonlyStatic2 = 8163,
	// ERR_RefReturnCall = 8164, we use more general ERR_EscapeCall now
	// ERR_RefReturnCall2 = 8165, we use more general ERR_EscapeCall2 now
	ERR_RefReturnParameter = 8166,
	ERR_RefReturnParameter2 = 8167,
	ERR_RefReturnLocal = 8168,
	ERR_RefReturnLocal2 = 8169,
	ERR_RefReturnStructThis = 8170,
	ERR_InitializeByValueVariableWithReference = 8171,
	ERR_InitializeByReferenceVariableWithValue = 8172,
	ERR_RefAssignmentMustHaveIdentityConversion = 8173,
	ERR_ByReferenceVariableMustBeInitialized = 8174,
	ERR_AnonDelegateCantUseLocal = 8175,
	ERR_BadIteratorLocalType = 8176,
	ERR_BadAsyncLocalType = 8177,
	ERR_RefReturningCallAndAwait = 8178,
	#endregion diagnostics for ref locals and ref returns introduced in C# 7
	#region stragglers for C# 7
	ERR_PredefinedValueTupleTypeNotFound = 8179, // We need a specific error code for ValueTuple as an IDE codefix depends on it (AddNuget)
	ERR_SemiOrLBraceOrArrowExpected = 8180,
	ERR_NewWithTupleTypeSyntax = 8181,
	ERR_PredefinedValueTupleTypeMustBeStruct = 8182,
	ERR_DiscardTypeInferenceFailed = 8183,
	ERR_MixedDeconstructionUnsupported = 8184,
	ERR_DeclarationExpressionNotPermitted = 8185,
	ERR_MustDeclareForeachIteration = 8186,
	ERR_TupleElementNamesInDeconstruction = 8187,
	ERR_ExpressionTreeContainsThrowExpression = 8188,
	ERR_DelegateRefMismatch = 8189,
	#endregion stragglers for C# 7
	#region diagnostics for parse options
	ERR_BadSourceCodeKind = 8190,
	ERR_BadDocumentationMode = 8191,
	ERR_BadLanguageVersion = 8192,
	#endregion
	// Available = 8193-8195
	#region diagnostics for out var
	ERR_ImplicitlyTypedOutVariableUsedInTheSameArgumentList = 8196,
	ERR_TypeInferenceFailedForImplicitlyTypedOutVariable = 8197,
	ERR_ExpressionTreeContainsOutVariable = 8198,
	#endregion diagnostics for out var
	#region more stragglers for C# 7
	ERR_VarInvocationLvalueReserved = 8199,
	//ERR_ExpressionVariableInConstructorOrFieldInitializer = 8200,
	//ERR_ExpressionVariableInQueryClause = 8201,
	ERR_PublicSignNetModule = 8202,
	ERR_BadAssemblyName = 8203,
	ERR_BadAsyncMethodBuilderTaskProperty = 8204,
	ERR_AttributesInLocalFuncDecl = 8205,
	ERR_TypeForwardedToMultipleAssemblies = 8206,
	ERR_ExpressionTreeContainsDiscard = 8207,
	ERR_PatternDynamicType = 8208,
	ERR_VoidAssignment = 8209,
	ERR_VoidInTuple = 8210,
	#endregion more stragglers for C# 7
	#region diagnostics introduced for C# 7.1
	ERR_Merge_conflict_marker_encountered = 8300,
	ERR_InvalidPreprocessingSymbol = 8301,
	ERR_FeatureNotAvailableInVersion7_1 = 8302,
	ERR_LanguageVersionCannotHaveLeadingZeroes = 8303,
	ERR_CompilerAndLanguageVersion = 8304,
	WRN_Experimental = 8305,
	ERR_TupleInferredNamesNotAvailable = 8306,
	ERR_TypelessTupleInAs = 8307,
	ERR_NoRefOutWhenRefOnly = 8308,
	ERR_NoNetModuleOutputWhenRefOutOrRefOnly = 8309,
	ERR_BadOpOnNullOrDefault = 8310,
	ERR_BadDynamicMethodArgDefaultLiteral = 8311,
	ERR_DefaultLiteralNotValid = 8312,
	ERR_DefaultInSwitch = 8313,
	ERR_PatternWrongGenericTypeInVersion = 8314,
	ERR_AmbigBinaryOpsOnDefault = 8315,
	#endregion diagnostics introduced for C# 7.1
	#region diagnostics introduced for C# 7.2
	ERR_FeatureNotAvailableInVersion7_2 = 8320,
	WRN_UnreferencedLocalFunction = 8321,
	ERR_DynamicLocalFunctionTypeParameter = 8322,
	ERR_BadNonTrailingNamedArgument = 8323,
	ERR_NamedArgumentSpecificationBeforeFixedArgumentInDynamicInvocation = 8324,
	#endregion diagnostics introduced for C# 7.2
	#region diagnostics introduced for ref readonly, ref ternary and ref-like features in C# 7.2
	ERR_RefConditionalAndAwait = 8325,
	ERR_RefConditionalNeedsTwoRefs = 8326,
	ERR_RefConditionalDifferentTypes = 8327,
	ERR_BadParameterModifiers = 8328,
	ERR_RefReadonlyNotField = 8329,
	ERR_RefReadonlyNotField2 = 8330,
	ERR_AssignReadonlyNotField = 8331,
	ERR_AssignReadonlyNotField2 = 8332,
	ERR_RefReturnReadonlyNotField = 8333,
	ERR_RefReturnReadonlyNotField2 = 8334,
	ERR_ExplicitReservedAttr = 8335,
	ERR_TypeReserved = 8336,
	ERR_RefExtensionMustBeValueTypeOrConstrainedToOne = 8337,
	ERR_InExtensionMustBeValueType = 8338,
	// ERR_BadParameterModifiersOrder = 8339, // Modifier ordering is relaxed
	ERR_FieldsInRoStruct = 8340,
	ERR_AutoPropsInRoStruct = 8341,
	ERR_FieldlikeEventsInRoStruct = 8342,
	ERR_RefStructInterfaceImpl = 8343,
	ERR_BadSpecialByRefIterator = 8344,
	ERR_FieldAutoPropCantBeByRefLike = 8345,
	ERR_StackAllocConversionNotPossible = 8346,
	ERR_EscapeCall = 8347,
	ERR_EscapeCall2 = 8348,
	ERR_EscapeOther = 8349,
	ERR_CallArgMixing = 8350,
	ERR_MismatchedRefEscapeInTernary = 8351,
	ERR_EscapeLocal = 8352,
	ERR_EscapeStackAlloc = 8353,
	ERR_RefReturnThis = 8354,
	ERR_OutAttrOnInParam = 8355,
	#endregion diagnostics introduced for ref readonly, ref ternary and ref-like features in C# 7.2
	ERR_PredefinedValueTupleTypeAmbiguous3 = 8356,
	ERR_InvalidVersionFormatDeterministic = 8357,
	ERR_AttributeCtorInParameter = 8358,
	#region diagnostics for FilterIsConstant warning message fix
	WRN_FilterIsConstantFalse = 8359,
	WRN_FilterIsConstantFalseRedundantTryCatch = 8360,
	#endregion diagnostics for FilterIsConstant warning message fix
	ERR_ConditionalInInterpolation = 8361,
	ERR_CantUseVoidInArglist = 8362,
	ERR_DefaultInPattern = 8363,
	ERR_InDynamicMethodArg = 8364,
	#region diagnostics introduced for C# 7.3
	ERR_FeatureNotAvailableInVersion7_3 = 8370,
	WRN_AttributesOnBackingFieldsNotAvailable = 8371,
	ERR_DoNotUseFixedBufferAttrOnProperty = 8372,
	ERR_RefLocalOrParamExpected = 8373,
	ERR_RefAssignNarrower = 8374,
	ERR_NewBoundWithUnmanaged = 8375,
	ERR_UnmanagedConstraintMustBeFirst = 8376,
	ERR_UnmanagedConstraintNotSatisfied = 8377,
	ERR_CantUseInOrOutInArglist = 8378,
	ERR_ConWithUnmanagedCon = 8379,
	ERR_UnmanagedBoundWithClass = 8380,
	ERR_InvalidStackAllocArray = 8381,
	ERR_ExpressionTreeContainsTupleBinOp = 8382,
	WRN_TupleBinopLiteralNameMismatch = 8383,
	ERR_TupleSizesMismatchForBinOps = 8384,
	ERR_ExprCannotBeFixed = 8385,
	ERR_InvalidObjectCreation = 8386,
	#endregion diagnostics introduced for C# 7.3
	ERR_OutVariableCannotBeByRef = 8387,

[BillWagner]

@mikkelbu That's the plan @rpetrusha are working on putting together. We'll also have a similar project for VB. Stay tuned. We'd love your help.

[pkulikov]

@mikkelbu have you considered pages under dotnet/docs/tree/master/docs/csharp/misc? There are about 800 compiler messages, probably mostly compiler errors, in that folder.
(There is the issue to combine those two locations: #1491)

[mikkelbu]

@pkulikov No, I forgot about that issue (eventhough I looked at it this week). Then it seems that this it is a smaller task, but still a large task IMHO.

[pkulikov]

As I understand, the first priority is to document error messages. That can be a smaller task, while documenting all the compiler warnings might be an epic :)

[rpetrusha]

There's also #2363, which treats storing C# and VB error messages/warnings in a unified directory per language. Moving files from a misc directory to the directory in language-reference is fairly trivial. Since we'd be moving everything, we can just do a global redirect of all requests for docs.microsoft.com/dotnet/csharp/misc to docs.microsoft.com/dotnet/csharp/language-reference/compiler-messages. But you're right, @pkulikov, that documenting all the compiler warnings might be epic. Providing genuinely useful content with examples is even more epic.

[BillWagner]

I've assigned this to the current milestone, with the goal of having the following actions completed during this sprint:

• Create a project to track tasks
• Create issues to find messages in ranges and create docs
• Add notes about where to find the source in both the VB and C# compilers for tests that help explain each issue.
• Add this work to the community project.

@rpetrusha Comment on this plan, or add new tasks that you think are reasonable.

[rpetrusha]

This looks good, @BillWagner. I think that we can link to the project to track tasks from the community contributor's project. In the project to track tasks, we should also include #1491 on it. I think that that should be the first item of work.