C# TypeSpec.GetSignatureForError方法代码示例

		public override void Error_ValueCannotBeConverted (ResolveContext ec, TypeSpec target, bool expl)
		{
			if (!expl && IsLiteral && 
				BuiltinTypeSpec.IsPrimitiveTypeOrDecimal (target) &&
				BuiltinTypeSpec.IsPrimitiveTypeOrDecimal (type)) {
				ec.Report.Error (31, loc, "Constant value `{0}' cannot be converted to a `{1}'",
					GetValueAsLiteral (), target.GetSignatureForError ());
			} else {
				base.Error_ValueCannotBeConverted (ec, target, expl);
			}
		}

		public FieldSpec CreateField (FieldInfo fi, TypeSpec declaringType)
		{
			Modifiers mod = 0;
			var fa = fi.Attributes;
			switch (fa & FieldAttributes.FieldAccessMask) {
				case FieldAttributes.Public:
					mod = Modifiers.PUBLIC;
					break;
				case FieldAttributes.Assembly:
					mod = Modifiers.INTERNAL;
					break;
				case FieldAttributes.Family:
					mod = Modifiers.PROTECTED;
					break;
				case FieldAttributes.FamORAssem:
					mod = Modifiers.PROTECTED | Modifiers.INTERNAL;
					break;
				default:
					// Ignore private fields (even for error reporting) to not require extra dependencies
					if ((IgnorePrivateMembers && !declaringType.IsStruct) ||
						HasAttribute (CustomAttributeData.GetCustomAttributes (fi), "CompilerGeneratedAttribute", CompilerServicesNamespace))
						return null;

					mod = Modifiers.PRIVATE;
					break;
			}

			TypeSpec field_type;

			try {
				field_type = ImportType (fi.FieldType, new DynamicTypeReader (fi));
			} catch (Exception e) {
				// TODO: I should construct fake TypeSpec based on TypeRef signature
				// but there is no way to do it with System.Reflection
				throw new InternalErrorException (e, "Cannot import field `{0}.{1}' referenced in assembly `{2}'",
					declaringType.GetSignatureForError (), fi.Name, declaringType.MemberDefinition.DeclaringAssembly);
			}

			var definition = new ImportedMemberDefinition (fi, field_type, this);

			if ((fa & FieldAttributes.Literal) != 0) {
				var c = Constant.CreateConstantFromValue (field_type, fi.GetRawConstantValue (), Location.Null);
				return new ConstSpec (declaringType, definition, field_type, fi, mod, c);
			}

			if ((fa & FieldAttributes.InitOnly) != 0) {
				if (field_type.BuiltinType == BuiltinTypeSpec.Type.Decimal) {
					var dc = ReadDecimalConstant (CustomAttributeData.GetCustomAttributes (fi));
					if (dc != null)
						return new ConstSpec (declaringType, definition, field_type, fi, mod, dc);
				}

				mod |= Modifiers.READONLY;
			} else {
				var req_mod = fi.GetRequiredCustomModifiers ();
				if (req_mod.Length > 0 && HasVolatileModifier (req_mod))
					mod |= Modifiers.VOLATILE;
			}

			if ((fa & FieldAttributes.Static) != 0) {
				mod |= Modifiers.STATIC;
			} else {
				// Fixed buffers cannot be static
				if (declaringType.IsStruct && field_type.IsStruct && field_type.IsNested &&
					HasAttribute (CustomAttributeData.GetCustomAttributes (fi), "FixedBufferAttribute", CompilerServicesNamespace)) {

					// TODO: Sanity check on field_type (only few types are allowed)
					var element_field = CreateField (fi.FieldType.GetField (FixedField.FixedElementName), declaringType);
					return new FixedFieldSpec (declaringType, definition, fi, element_field, mod);
				}
			}

			return new FieldSpec (declaringType, definition, field_type, fi, mod);
		}

		protected bool VerifyParameterCompatibility (ResolveContext ec, TypeInferenceContext tic, TypeSpec delegate_type, AParametersCollection invoke_pd, bool ignore_errors)
		{
			if (Parameters.Count != invoke_pd.Count) {
				if (ignore_errors)
					return false;
				
				ec.Report.Error (1593, loc, "Delegate `{0}' does not take `{1}' arguments",
					      delegate_type.GetSignatureForError (), Parameters.Count.ToString ());
				return false;
			}

			bool has_implicit_parameters = !HasExplicitParameters;
			bool error = false;

			for (int i = 0; i < Parameters.Count; ++i) {
				Parameter.Modifier p_mod = invoke_pd.FixedParameters [i].ModFlags;
				if (Parameters.FixedParameters [i].ModFlags != p_mod && p_mod != Parameter.Modifier.PARAMS) {
					if (ignore_errors)
						return false;
					
					if (p_mod == Parameter.Modifier.NONE)
						ec.Report.Error (1677, Parameters[i].Location, "Parameter `{0}' should not be declared with the `{1}' keyword",
							      (i + 1).ToString (), Parameter.GetModifierSignature (Parameters [i].ModFlags));
					else
						ec.Report.Error (1676, Parameters[i].Location, "Parameter `{0}' must be declared with the `{1}' keyword",
							      (i+1).ToString (), Parameter.GetModifierSignature (p_mod));
					error = true;
				}

				if (has_implicit_parameters)
					continue;

				TypeSpec type = invoke_pd.Types [i];

				if (tic != null)
					type = tic.InflateGenericArgument (ec, type);
				
				if (!TypeSpecComparer.IsEqual (type, Parameters.Types [i])) {
					if (ignore_errors)
						return false;
					
					ec.Report.Error (1678, Parameters [i].Location, "Parameter `{0}' is declared as type `{1}' but should be `{2}'",
						      (i+1).ToString (),
						      Parameters.Types [i].GetSignatureForError (),
						      invoke_pd.Types [i].GetSignatureForError ());
					error = true;
				}
			}

			return !error;
		}

		protected bool VerifyExplicitParameters (ResolveContext ec, TypeInferenceContext tic, TypeSpec delegate_type, AParametersCollection parameters)
		{
			if (VerifyParameterCompatibility (ec, tic, delegate_type, parameters, ec.IsInProbingMode))
				return true;

			if (!ec.IsInProbingMode)
				ec.Report.Error (1661, loc,
					"Cannot convert `{0}' to delegate type `{1}' since there is a parameter mismatch",
					GetSignatureForError (), delegate_type.GetSignatureForError ());

			return false;
		}

		static void CheckConversion (IMemberContext mc, MemberSpec context, TypeSpec atype, TypeParameterSpec tparam, TypeSpec ttype, Location loc)
		{
			var expr = new EmptyExpression (atype);
			if (!Convert.ImplicitStandardConversionExists (expr, ttype)) {
				mc.Compiler.Report.SymbolRelatedToPreviousError (tparam);
				if (TypeManager.IsValueType (atype)) {
					mc.Compiler.Report.Error (315, loc, "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no boxing conversion from `{0}' to `{3}'",
						atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
				} else if (atype.IsGenericParameter) {
					mc.Compiler.Report.Error (314, loc, "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no boxing or type parameter conversion from `{0}' to `{3}'",
						atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
				} else {
					mc.Compiler.Report.Error (311, loc, "The type `{0}' cannot be used as type parameter `{1}' in the generic type or method `{2}'. There is no implicit reference conversion from `{0}' to `{3}'",
						atype.GetSignatureForError (), tparam.GetSignatureForError (), context.GetSignatureForError (), ttype.GetSignatureForError ());
				}
			}
		}

		protected virtual ParametersCompiled ResolveParameters (ResolveContext ec, TypeInferenceContext tic, TypeSpec delegate_type)
		{
			var delegate_parameters = Delegate.GetParameters (delegate_type);

			if (Parameters == ParametersCompiled.Undefined) {
				//
				// We provide a set of inaccessible parameters
				//
				Parameter[] fixedpars = new Parameter[delegate_parameters.Count];

				for (int i = 0; i < delegate_parameters.Count; i++) {
					Parameter.Modifier i_mod = delegate_parameters.FixedParameters [i].ModFlags;
					if ((i_mod & Parameter.Modifier.OUT) != 0) {
						if (!ec.IsInProbingMode) {
							ec.Report.Error (1688, loc,
								"Cannot convert anonymous method block without a parameter list to delegate type `{0}' because it has one or more `out' parameters",
								delegate_type.GetSignatureForError ());
						}

						return null;
					}
					fixedpars[i] = new Parameter (
						new TypeExpression (delegate_parameters.Types [i], loc), null,
						delegate_parameters.FixedParameters [i].ModFlags, null, loc);
				}

				return ParametersCompiled.CreateFullyResolved (fixedpars, delegate_parameters.Types);
			}

			if (!VerifyExplicitParameters (ec, delegate_type, delegate_parameters)) {
				return null;
			}

			return Parameters;
		}

		//
		// Attempts to do a compile-time folding of a constant cast and handles
		// error reporting for constant overlows only, on normal conversion
		// errors returns null
		// 
		public Constant Reduce (ResolveContext ec, TypeSpec target_type)
		{
			try {
				return TryReduceConstant (ec, target_type);
			} catch (OverflowException) {
				if (ec.ConstantCheckState && Type.BuiltinType != BuiltinTypeSpec.Type.Decimal) {
					ec.Report.Error (221, loc,
						"Constant value `{0}' cannot be converted to a `{1}' (use `unchecked' syntax to override)",
						GetValueAsLiteral (), target_type.GetSignatureForError ());
				} else {
					Error_ValueCannotBeConverted (ec, target_type, false);
				}

				return New.Constantify (target_type, loc);
			}
		}

		public static void Error1599 (Location loc, TypeSpec t, Report Report)
		{
			Report.Error (1599, loc, "Method or delegate cannot return type `{0}'", t.GetSignatureForError ());
		}

		public virtual Constant ConvertImplicitly (TypeSpec type)
		{
			if (this.type == type)
				return this;

			if (!Convert.ImplicitNumericConversionExists (this.type, type))
				return null;

			bool fail;			
			object constant_value = ChangeType (GetValue (), type, out fail);
			if (fail){
				//
				// We should always catch the error before this is ever
				// reached, by calling Convert.ImplicitStandardConversionExists
				//
				throw new InternalErrorException ("Missing constant conversion between `{0}' and `{1}'",
				 Type.GetSignatureForError (), type.GetSignatureForError ());
			}

			return CreateConstantFromValue (type, constant_value, loc);
		}

			void Error_AmbiguousIEnumerable (ResolveContext rc, TypeSpec type)
			{
				rc.Report.SymbolRelatedToPreviousError (type);
				rc.Report.Error (1640, loc,
					"foreach statement cannot operate on variables of type `{0}' because it contains multiple implementation of `{1}'. Try casting to a specific implementation",
					type.GetSignatureForError (), TypeManager.generic_ienumerable_type.GetSignatureForError ());
			}

        protected void Error_ValueCannotBeConvertedCore(ResolveContext ec, Location loc, TypeSpec target, bool expl)
        {
            // The error was already reported as CS1660
            if (type == InternalType.AnonymousMethod)
                return;

            /*
            if (TypeManager.IsGenericParameter (Type) && TypeManager.IsGenericParameter (target) && type.Name == target.Name) {
                string sig1 = type.DeclaringMethod == null ?
                    TypeManager.CSharpName (type.DeclaringType) :
                    TypeManager.CSharpSignature (type.DeclaringMethod);
                string sig2 = target.DeclaringMethod == null ?
                    TypeManager.CSharpName (target.DeclaringType) :
                    TypeManager.CSharpSignature (target.DeclaringMethod);
                ec.Report.ExtraInformation (loc,
                    String.Format (
                        "The generic parameter `{0}' of `{1}' cannot be converted to the generic parameter `{0}' of `{2}' (in the previous ",
                        Type.Name, sig1, sig2));
            } else if (Type.MetaInfo.FullName == target.MetaInfo.FullName) {
                ec.Report.ExtraInformation (loc,
                    String.Format (
                    "The type `{0}' has two conflicting definitions, one comes from `{1}' and the other from `{2}' (in the previous ",
                    Type.MetaInfo.FullName, Type.Assembly.FullName, target.Assembly.FullName));
            }
            */
            if (expl) {
                ec.Report.Error (30, loc, "Cannot convert type `{0}' to `{1}'",
                    TypeManager.CSharpName (type), TypeManager.CSharpName (target));
                return;
            }

            ec.Report.DisableReporting ();
            bool expl_exists = Convert.ExplicitConversion (ec, this, target, Location.Null) != null;
            ec.Report.EnableReporting ();

            if (expl_exists) {
                ec.Report.Error (266, loc, "Cannot implicitly convert type `{0}' to `{1}'. " +
                          "An explicit conversion exists (are you missing a cast?)",
                    TypeManager.CSharpName (Type), TypeManager.CSharpName (target));
                return;
            }

            ec.Report.Error (29, loc, "Cannot implicitly convert type `{0}' to `{1}'",
                type.GetSignatureForError (), target.GetSignatureForError ());
        }

//.........这里部分代码省略.........
				s_x = FindMostSpecificSource (rc, candidates, source.Type, source_type_expr, !implicitOnly);
				if (s_x == null)
					return null;

				t_x = FindMostSpecificTarget (candidates, target, !implicitOnly);
				if (t_x == null)
					return null;

				most_specific_operator = null;
				for (int i = 0; i < candidates.Count; ++i) {
					if (candidates[i].ReturnType == t_x && candidates[i].Parameters.Types[0] == s_x) {
						most_specific_operator = candidates[i];
						break;
					}
				}

				if (most_specific_operator == null) {
					//
					// Unless running in probing more
					//
					if ((restr & UserConversionRestriction.ProbingOnly) == 0) {
						MethodSpec ambig_arg = candidates [0];
						most_specific_operator = candidates [1];
						/*
						foreach (var candidate in candidates) {
							if (candidate.ReturnType == t_x)
								most_specific_operator = candidate;
							else if (candidate.Parameters.Types[0] == s_x)
								ambig_arg = candidate;
						}
						*/
						rc.Report.Error (457, loc,
							"Ambiguous user defined operators `{0}' and `{1}' when converting from `{2}' to `{3}'",
							ambig_arg.GetSignatureForError (), most_specific_operator.GetSignatureForError (),
							source.Type.GetSignatureForError (), target.GetSignatureForError ());
					}

					return ErrorExpression.Instance;
				}
			}

			//
			// Convert input type when it's different to best operator argument
			//
			if (s_x != source_type) {
				var c = source as Constant;
				if (c != null) {
					source = c.Reduce (rc, s_x);
					if (source == null)
						c = null;
				}

				if (c == null) {
					source = implicitOnly ?
						ImplicitConversionStandard (rc, source_type_expr, s_x, loc) :
						ExplicitConversionStandard (rc, source_type_expr, s_x, loc);
				}
			} else {
				source = source_type_expr;
			}

			source = new UserCast (most_specific_operator, source, loc).Resolve (rc);

			//
			// Convert result type when it's different to best operator return type
			//

		bool CheckConflictingInheritedConstraint (TypeSpec ba, TypeSpec bb, IMemberContext context, Location loc)
		{
			if (!TypeManager.IsSubclassOf (ba, bb) && !TypeManager.IsSubclassOf (bb, ba)) {
				context.Compiler.Report.Error (455, loc,
					"Type parameter `{0}' inherits conflicting constraints `{1}' and `{2}'",
					tparam.Value,
					ba.GetSignatureForError (), bb.GetSignatureForError ());
				return false;
			}

			return true;
		}

		public void LoadMembers (TypeSpec declaringType, bool onlyTypes, ref MemberCache cache)
		{
			//
			// Not interested in members of nested private types unless the importer needs them
			//
			if (declaringType.IsPrivate && importer.IgnorePrivateMembers) {
				cache = MemberCache.Empty;
				return;
			}

			var loading_type = (MetaType) provider;
			const BindingFlags all_members = BindingFlags.DeclaredOnly |
				BindingFlags.Static | BindingFlags.Instance |
				BindingFlags.Public | BindingFlags.NonPublic;

			const MethodAttributes explicit_impl = MethodAttributes.NewSlot |
					MethodAttributes.Virtual | MethodAttributes.HideBySig |
					MethodAttributes.Final;

			Dictionary<MethodBase, MethodSpec> possible_accessors = null;
			List<EventSpec> imported_events = null;
			EventSpec event_spec;
			MemberSpec imported;
			MethodInfo m;
			MemberInfo[] all;
			try {
				all = loading_type.GetMembers (all_members);
			} catch (Exception e) {
				throw new InternalErrorException (e, "Could not import type `{0}' from `{1}'",
					declaringType.GetSignatureForError (), declaringType.MemberDefinition.DeclaringAssembly.FullName);
			}

			if (cache == null) {
				cache = new MemberCache (all.Length);

				//
				// Do the types first as they can be referenced by the members before
				// they are found or inflated
				//
				foreach (var member in all) {
					if (member.MemberType != MemberTypes.NestedType)
						continue;

					var t = (MetaType) member;

					// Ignore compiler generated types, mostly lambda containers
					if ((t.Attributes & TypeAttributes.VisibilityMask) == TypeAttributes.NestedPrivate && importer.IgnorePrivateMembers)
						continue;

					try {
						imported = importer.CreateNestedType (t, declaringType);
					} catch (Exception e) {
						throw new InternalErrorException (e, "Could not import nested type `{0}' from `{1}'",
							t.FullName, declaringType.MemberDefinition.DeclaringAssembly.FullName);
					}

					cache.AddMemberImported (imported);
				}

				foreach (var member in all) {
					if (member.MemberType != MemberTypes.NestedType)
						continue;

					var t = (MetaType) member;

					if ((t.Attributes & TypeAttributes.VisibilityMask) == TypeAttributes.NestedPrivate && importer.IgnorePrivateMembers)
						continue;

					importer.ImportTypeBase (t);
				}
			}

			//
			// Load base interfaces first to minic behaviour of compiled members
			//
			if (declaringType.IsInterface && declaringType.Interfaces != null) {
				foreach (var iface in declaringType.Interfaces) {
					cache.AddInterface (iface);
				}
			}

			if (!onlyTypes) {
				//
				// The logic here requires methods to be returned first which seems to work for both Mono and .NET
				//
				foreach (var member in all) {
					switch (member.MemberType) {
					case MemberTypes.Constructor:
					case MemberTypes.Method:
						MethodBase mb = (MethodBase) member;
						var attrs = mb.Attributes;

						if ((attrs & MethodAttributes.MemberAccessMask) == MethodAttributes.Private) {
							if (importer.IgnorePrivateMembers)
								continue;

							// Ignore explicitly implemented members
							if ((attrs & explicit_impl) == explicit_impl)
								continue;

//.........这里部分代码省略.........

		//
		// Returns AnonymousMethod container if this anonymous method
		// expression can be implicitly converted to the delegate type `delegate_type'
		//
		public Expression Compatible (ResolveContext ec, TypeSpec type)
		{
			Expression am;
			if (compatibles.TryGetValue (type, out am))
				return am;

			TypeSpec delegate_type = CompatibleChecks (ec, type);
			if (delegate_type == null)
				return null;

			//
			// At this point its the first time we know the return type that is 
			// needed for the anonymous method.  We create the method here.
			//

			var invoke_mb = Delegate.GetInvokeMethod (delegate_type);
			TypeSpec return_type = invoke_mb.ReturnType;

			//
			// Second: the return type of the delegate must be compatible with 
			// the anonymous type.   Instead of doing a pass to examine the block
			// we satisfy the rule by setting the return type on the EmitContext
			// to be the delegate type return type.
			//

			var body = CompatibleMethodBody (ec, null, return_type, delegate_type);
			if (body == null)
				return null;

			bool etree_conversion = delegate_type != type;

			try {
				if (etree_conversion) {
					if (ec.HasSet (ResolveContext.Options.ExpressionTreeConversion)) {
						//
						// Nested expression tree lambda use same scope as parent
						// lambda, this also means no variable capturing between this
						// and parent scope
						//
						am = body.Compatible (ec, ec.CurrentAnonymousMethod);

						//
						// Quote nested expression tree
						//
						if (am != null)
							am = new Quote (am);
					} else {
						int errors = ec.Report.Errors;

						using (ec.Set (ResolveContext.Options.ExpressionTreeConversion)) {
							am = body.Compatible (ec);
						}

						//
						// Rewrite expressions into expression tree when targeting Expression<T>
						//
						if (am != null && errors == ec.Report.Errors)
							am = CreateExpressionTree (ec, delegate_type);
					}
				} else {
					if (Block.IsAsync) {
						var rt = body.ReturnType;
						if (rt.Kind != MemberKind.Void &&
							rt != ec.Module.PredefinedTypes.Task.TypeSpec &&
							!rt.IsGenericTask) {
							ec.Report.Error (4010, loc, "Cannot convert async {0} to delegate type `{1}'",
								GetSignatureForError (), type.GetSignatureForError ());
						}

						AsyncInitializer.Create (ec, body.Block, body.Parameters, ec.CurrentMemberDefinition.Parent, rt, loc);
					}

					am = body.Compatible (ec);
				}
			} catch (CompletionResult) {
				throw;
			} catch (Exception e) {
				throw new InternalErrorException (e, loc);
			}

			if (!ec.IsInProbingMode) {
				compatibles.Add (type, am ?? EmptyExpression.Null);
			}

			return am;
		}