Improved overload resolution by implementing 14.4.2.2 Better function member.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@454 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpAmbience.cs

@@ -503,9 +503,9 @@ namespace ICSharpCode.Core
 				ConstructedReturnType rt = (ConstructedReturnType)returnType;
 				UnpackNestedType(builder, rt.BaseType);
 				builder.Append('<');
-				for (int i = 0; i < rt.TypeParameters.Count; ++i) {
+				for (int i = 0; i < rt.TypeArguments.Count; ++i) {
 					if (i > 0) builder.Append(", ");
-					builder.Append(Convert(rt.TypeParameters[i]));
+					builder.Append(Convert(rt.TypeArguments[i]));
 				}
 				builder.Append('>');
 			}

src/AddIns/BackendBindings/CSharpBinding/Project/Src/CSharpCompletionBinding.cs

@@ -194,7 +194,7 @@ namespace CSharpBinding
 		bool IsInComment(SharpDevelopTextAreaControl editor)
 		{
 			Parser.ExpressionFinder ef = new Parser.ExpressionFinder(editor.FileName);
-			int cursor = editor.ActiveTextAreaControl.Caret.Offset;
+			int cursor = editor.ActiveTextAreaControl.Caret.Offset - 1;
 			return ef.FilterComments(editor.Document.GetText(0, cursor + 1), ref cursor) == null;
 		}
 		

src/AddIns/BackendBindings/VBNetBinding/Project/Src/VBNetAmbience.cs

@@ -505,9 +505,9 @@ namespace VBNetBinding
 				ConstructedReturnType rt = (ConstructedReturnType)returnType;
 				UnpackNestedType(builder, rt.BaseType);
 				builder.Append("(Of ");
-				for (int i = 0; i < rt.TypeParameters.Count; ++i) {
+				for (int i = 0; i < rt.TypeArguments.Count; ++i) {
 					if (i > 0) builder.Append(", ");
-					builder.Append(Convert(rt.TypeParameters[i]));
+					builder.Append(Convert(rt.TypeArguments[i]));
 				}
 				builder.Append(')');
 			}

src/Main/Base/Project/Src/Dom/Implementations/ConstructedReturnType.cs

@@ -27,7 +27,7 @@ namespace ICSharpCode.SharpDevelop.Dom
 		List<IReturnType> typeParameters;
 		IReturnType baseType;
 		
-		public List<IReturnType> TypeParameters {
+		public List<IReturnType> TypeArguments {
 			get {
 				return typeParameters;
 			}
@@ -78,7 +78,7 @@ namespace ICSharpCode.SharpDevelop.Dom
 			} else if (t is ArrayReturnType) {
 				return CheckReturnType(((ArrayReturnType)t).ElementType);
 			} else if (t is ConstructedReturnType) {
-				foreach (IReturnType para in ((ConstructedReturnType)t).TypeParameters) {
+				foreach (IReturnType para in ((ConstructedReturnType)t).TypeArguments) {
 					if (CheckReturnType(para)) return true;
 				}
 				return false;
@@ -136,9 +136,9 @@ namespace ICSharpCode.SharpDevelop.Dom
 					return new ArrayReturnType(t, input.ArrayDimensions);
 			} else if (input is ConstructedReturnType) {
 				ConstructedReturnType r = (ConstructedReturnType)input;
-				List<IReturnType> para = new List<IReturnType>(r.TypeParameters.Count);
+				List<IReturnType> para = new List<IReturnType>(r.TypeArguments.Count);
-				for (int i = 0; i < r.TypeParameters.Count; ++i) {
+				for (int i = 0; i < r.TypeArguments.Count; ++i) {
-					para.Add(TranslateType(r.TypeParameters[i], typeParameters, convertForMethod));
+					para.Add(TranslateType(r.TypeArguments[i], typeParameters, convertForMethod));
 				}
 				return new ConstructedReturnType(r.baseType, para);
 			}

src/Main/Base/Project/Src/Dom/MemberLookupHelper.cs

@@ -155,6 +155,7 @@ namespace ICSharpCode.SharpDevelop.Dom
 		                                  out bool acceptableMatch,
 		                                  out IReturnType[][] inferredTypeParameters)
 		{
+			// § 14.4.2 Overload resolution
 			acceptableMatch = false;
 			inferredTypeParameters = null;
 			if (list.Count == 0) return new int[] {};
@@ -163,9 +164,9 @@ namespace ICSharpCode.SharpDevelop.Dom
 			bool[] needToExpand = new bool[list.Count];
 			int maxScore = 0;
 			int baseScore = 0;
-			for (int i = 0; i < list.Count; i++) {
 			int score;
 			bool expanded;
+			for (int i = 0; i < list.Count; i++) {
 				if (IsApplicable(list[i].Parameters, arguments, allowAdditionalArguments, out score, out expanded)) {
 					acceptableMatch = true;
 					score = int.MaxValue;
@@ -183,8 +184,41 @@ namespace ICSharpCode.SharpDevelop.Dom
 			
 			// The first step is to expand the methods and do type argument substitution
 			IReturnType[][] expandedParameters = ExpandParametersAndSubstitute(list, arguments, maxScore, ranking, needToExpand, out inferredTypeParameters);
-			// § 14.4.2.2 Better function member
 			
+			// find the best function member
+			
+			score = baseScore + 2;
+			int bestIndex = -1;
+			for (int i = 0; i < ranking.Length; i++) {
+				if (ranking[i] == maxScore) {
+					// the best function member is the one that is better than all other function members
+					if (bestIndex < 0) {
+						ranking[i] = score;
+						bestIndex = i;
+					} else {
+						switch (GetBetterFunctionMember(arguments,
+						                                list[i], expandedParameters[i], needToExpand[i],
+						                                list[bestIndex], expandedParameters[bestIndex], needToExpand[bestIndex]))
+						{
+							case 0:
+								// neither member is better
+								ranking[i] = score;
+								break;
+							case 1:
+								// the new member is better
+								ranking[i] = ++score;
+								bestIndex = i;
+								break;
+							case 2:
+								// the old member is better
+								ranking[i] = score - 1;
+								// this is not really correct, normally we would need to
+								// compare the member with other members
+								break;
+						}
+					}
+				}
+			}
 			
 			return ranking;
 		}
@@ -224,9 +258,104 @@ namespace ICSharpCode.SharpDevelop.Dom
 			return expandedParameters;
 		}
 		
-		static bool IsBetterFunctionMember()
+		/// <summary>
+		/// Gets which function member is better. (§ 14.4.2.2)
+		/// </summary>
+		/// <param name="arguments">The arguments passed to the function</param>
+		/// <param name="m1">The first method</param>
+		/// <param name="parameters1">The expanded and substituted parameters of the first method</param>
+		/// <param name="m2">The second method</param>
+		/// <param name="parameters2">The expanded and substituted parameters of the second method</param>
+		/// <returns>0 if neither method is better. 1 if m1 is better. 2 if m2 is better.</returns>
+		static int GetBetterFunctionMember(IReturnType[] arguments,
+		                                   IMethodOrProperty m1, IReturnType[] parameters1, bool isExpanded1,
+		                                   IMethodOrProperty m2, IReturnType[] parameters2, bool isExpanded2)
 		{
-			return false;
+			int length = Math.Min(Math.Min(parameters1.Length, parameters2.Length), arguments.Length);
+			bool foundBetterParamIn1 = false;
+			bool foundBetterParamIn2 = false;
+			for (int i = 0; i < length; i++) {
+				if (arguments[i] == null)
+					continue;
+				int res = GetBetterConversion(arguments[i], parameters1[i], parameters2[i]);
+				if (res == 1) foundBetterParamIn1 = true;
+				if (res == 2) foundBetterParamIn2 = true;
+			}
+			if (foundBetterParamIn1 && !foundBetterParamIn2)
+				return 1;
+			if (foundBetterParamIn2 && !foundBetterParamIn1)
+				return 2;
+			if (foundBetterParamIn1 && foundBetterParamIn2)
+				return 0; // ambigous
+			// If none conversion is better than any other, it is possible that the
+			// expanded parameter lists are the same:
+			for (int i = 0; i < length; i++) {
+				if (!object.Equals(parameters1[i], parameters2[i])) {
+					// if expanded parameters are not the same, neither function member is better
+					return 0;
+				}
+			}
+			
+			// the expanded parameters are the same, apply the tie-breaking rules from the spec:
+			
+			// if one method is generic and the other non-generic, the non-generic is better
+			bool m1IsGeneric = (m1 is IMethod) ? ((IMethod)m1).TypeParameters.Count > 0 : false;
+			bool m2IsGeneric = (m2 is IMethod) ? ((IMethod)m2).TypeParameters.Count > 0 : false;
+			if (m1IsGeneric && !m2IsGeneric) return 2;
+			if (m2IsGeneric && !m1IsGeneric) return 1;
+			
+			// for params parameters: non-expanded calls are better
+			if (isExpanded1 && !isExpanded2) return 2;
+			if (isExpanded2 && !isExpanded1) return 1;
+			
+			// if the number of parameters is different, the one with more parameters is better
+			// this occurs when only when both methods are expanded
+			if (m1.Parameters.Count > m2.Parameters.Count) return 1;
+			if (m2.Parameters.Count > m1.Parameters.Count) return 2;
+			
+			IReturnType[] m1ParamTypes = new IReturnType[m1.Parameters.Count];
+			IReturnType[] m2ParamTypes = new IReturnType[m2.Parameters.Count];
+			for (int i = 0; i < m1ParamTypes.Length; i++) {
+				m1ParamTypes[i] = m1.Parameters[i].ReturnType;
+				m2ParamTypes[i] = m2.Parameters[i].ReturnType;
+			}
+			return GetMoreSpecific(m1ParamTypes, m2ParamTypes);
+		}
+		
+		/// <summary>
+		/// Gets which return type list is more specific.
+		/// § 14.4.2.2: types with generic arguments are less specific than types with fixed arguments
+		/// </summary>
+		/// <returns>0 if both are equally specific, 1 if <paramref name="r"/> is more specific,
+		/// 2 if <paramref name="s"/> is more specific.</returns>
+		static int GetMoreSpecific(IList<IReturnType> r, IList<IReturnType> s)
+		{
+			bool foundMoreSpecificParamIn1 = false;
+			bool foundMoreSpecificParamIn2 = false;
+			int length = Math.Min(r.Count, s.Count);
+			for (int i = 0; i < length; i++) {
+				int res = GetMoreSpecific(r[i], s[i]);
+				if (res == 1) foundMoreSpecificParamIn1 = true;
+				if (res == 2) foundMoreSpecificParamIn2 = true;
+			}
+			if (foundMoreSpecificParamIn1 && !foundMoreSpecificParamIn2)
+				return 1;
+			if (foundMoreSpecificParamIn2 && !foundMoreSpecificParamIn1)
+				return 2;
+			return 0;
+		}
+		
+		static int GetMoreSpecific(IReturnType r, IReturnType s)
+		{
+			if (r is GenericReturnType && !(s is GenericReturnType))
+				return 2;
+			if (s is GenericReturnType && !(r is GenericReturnType))
+				return 1;
+			if (r is ArrayReturnType && s is ArrayReturnType)
+				return GetMoreSpecific(((ArrayReturnType)r).ElementType, ((ArrayReturnType)s).ElementType);
+			if (r is ConstructedReturnType && s is ConstructedReturnType)
+				return GetMoreSpecific(((ConstructedReturnType)r).TypeArguments, ((ConstructedReturnType)s).TypeArguments);
+			return 0;
 		}
 		#endregion
 		
@@ -272,7 +401,7 @@ namespace ICSharpCode.SharpDevelop.Dom
 						case "System.Collections.Generic.IList":
 						case "System.Collections.Generic.ICollection":
 						case "System.Collections.Generic.IEnumerable":
-							return InferTypeArgument(ea.ElementType, ((ConstructedReturnType)passedArgument).TypeParameters[0], outputArray);
+							return InferTypeArgument(ea.ElementType, ((ConstructedReturnType)passedArgument).TypeArguments[0], outputArray);
 					}
 				}
 				// If P is an array type, and A is not an array type of the same rank,
@@ -293,9 +422,9 @@ namespace ICSharpCode.SharpDevelop.Dom
 				// For our purposes, we can simplify enourmously:
 				ConstructedReturnType passed = passedArgument as ConstructedReturnType;
 				if (passed == null) return false;
-				int count = Math.Min(constructed.TypeParameters.Count, passed.TypeParameters.Count);
+				int count = Math.Min(constructed.TypeArguments.Count, passed.TypeArguments.Count);
 				for (int i = 0; i < count; i++) {
-					InferTypeArgument(constructed.TypeParameters[i], passed.TypeParameters[i], outputArray);
+					InferTypeArgument(constructed.TypeArguments[i], passed.TypeArguments[i], outputArray);
 				}
 			}
 			return true;

src/Main/Base/Project/Src/Gui/Components/StatusBar/SdStatusBar.cs

@@ -123,8 +123,10 @@ namespace ICSharpCode.SharpDevelop.Gui
 		{
 			taskName = name;
 			this.totalWork = totalWork;
+			if (this.IsHandleCreated) {
 				this.BeginInvoke(new MethodInvoker(MakeVisible));
 			}
+		}
 		
 		void MakeVisible()
 		{
@@ -165,8 +167,10 @@ namespace ICSharpCode.SharpDevelop.Gui
 		public void Done()
 		{
 			taskName = null;
+			if (this.IsHandleCreated) {
 				this.BeginInvoke(new MethodInvoker(MakeInvisible));
 			}
+		}
 		
 		string taskName;
 		

src/Main/Base/Test/GenericResolverTests.cs

@@ -70,7 +70,7 @@ class TestClass {
 			Assert.AreEqual(1, m.Parameters.Count);
 			Assert.IsTrue(m.Parameters[0].ReturnType is ConstructedReturnType);
 			Assert.AreEqual("System.Collections.Generic.IEnumerable", m.Parameters[0].ReturnType.FullyQualifiedName);
-			Assert.AreEqual("TestClass", ((ConstructedReturnType)m.Parameters[0].ReturnType).TypeParameters[0].FullyQualifiedName);
+			Assert.AreEqual("TestClass", ((ConstructedReturnType)m.Parameters[0].ReturnType).TypeArguments[0].FullyQualifiedName);
 		}
 		
 		[Test]
@@ -92,7 +92,7 @@ class TestClass {
 			Assert.IsTrue(result is TypeResolveResult);
 			Assert.AreEqual("System.Collections.Generic.List", ((TypeResolveResult)result).ResolvedClass.FullyQualifiedName);
 			Assert.IsTrue(result.ResolvedType is ConstructedReturnType);
-			Assert.AreEqual("System.String", ((ConstructedReturnType)result.ResolvedType).TypeParameters[0].FullyQualifiedName);
+			Assert.AreEqual("System.String", ((ConstructedReturnType)result.ResolvedType).TypeArguments[0].FullyQualifiedName);
 		}
 		
 		[Test]

src/Main/Base/Test/ICSharpCode.SharpDevelop.Tests.csproj

@@ -49,6 +49,7 @@
     <Compile Include="InnerClassesResolverTests.cs" />
     <Compile Include="RefactoringTests.cs" />
     <Compile Include="SearchClassTests.cs" />
+    <Compile Include="OverloadFinding.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Project\ICSharpCode.SharpDevelop.csproj">

src/Main/Base/Test/NRefactoryResolverTests.cs

@@ -1,4 +1,4 @@
-// <file>
+// <file>
 //     <copyright see="prj:///doc/copyright.txt">2002-2005 AlphaSierraPapa</copyright>
 //     <license see="prj:///doc/license.txt">GNU General Public License</license>
 //     <owner name="Daniel Grunwald" email="daniel@danielgrunwald.de"/>
@@ -25,7 +25,8 @@ namespace ICSharpCode.SharpDevelop.Tests
 			p.ParseMethodBodies = false;
 			p.Parse();
 			DefaultProjectContent pc = new DefaultProjectContent();
-			pc.ReferencedContents.Add(corLib);
+			pc.ReferencedContents.Add(ProjectContentRegistry.Mscorlib);
+			pc.ReferencedContents.Add(ProjectContentRegistry.WinForms);
 			ParserService.ForceProjectContent(pc);
 			lastPC = pc;
 			NRefactoryASTConvertVisitor visitor = new NRefactoryASTConvertVisitor(pc);
@@ -48,7 +49,8 @@ namespace ICSharpCode.SharpDevelop.Tests
 			p.Parse();
 			DefaultProjectContent pc = new DefaultProjectContent();
 			ParserService.ForceProjectContent(pc);
-			pc.ReferencedContents.Add(corLib);
+			pc.ReferencedContents.Add(ProjectContentRegistry.Mscorlib);
+			pc.ReferencedContents.Add(ProjectContentRegistry.WinForms);
 			pc.Language = LanguageProperties.VBNet;
 			lastPC = pc;
 			NRefactoryASTConvertVisitor visitor = new NRefactoryASTConvertVisitor(pc);
@@ -92,7 +94,7 @@ namespace ICSharpCode.SharpDevelop.Tests
 		public T Resolve<T>(string program, string expression, int line) where T : ResolveResult
 		{
 			ResolveResult rr = Resolve(program, expression, line);
-			Assert.IsNotNull(rr);
+			Assert.IsNotNull(rr, "Resolve returned null");
 			Assert.IsTrue(rr is T, "result is " + typeof(T).Name);
 			return (T)rr;
 		}
@@ -100,12 +102,10 @@ namespace ICSharpCode.SharpDevelop.Tests
 		public T ResolveVB<T>(string program, string expression, int line) where T : ResolveResult
 		{
 			ResolveResult rr = ResolveVB(program, expression, line);
-			Assert.IsNotNull(rr);
+			Assert.IsNotNull(rr, "Resolve returned null");
 			Assert.IsTrue(rr is T, "result is " + typeof(T).Name);
 			return (T)rr;
 		}
-		
-		IProjectContent corLib = ProjectContentRegistry.Mscorlib;
 		#endregion
 		
 		#region Test for old issues (Fidalgo)

src/Main/Base/Test/OverloadFinding.cs

@@ -0,0 +1,81 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt">2002-2005 AlphaSierraPapa</copyright>
+//     <license see="prj:///doc/license.txt">GNU General Public License</license>
+//     <owner name="Daniel Grunwald" email="daniel@danielgrunwald.de"/>
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using System.Text;
+using NUnit.Framework;
+using ICSharpCode.SharpDevelop.Dom;
+
+namespace ICSharpCode.SharpDevelop.Tests
+{
+	[TestFixture]
+	public class OverloadFinding
+	{
+		[Test] public void Simple()
+		{
+			Test("(\"Hallo\")", 0, "(string a)", "(int b)");
+			Test("(2)", 1, "(string a)", "(int b)");
+		}
+		
+		[Test] public void WinForms()
+		{
+			string[] overloads = {"(object a)", "(TextBoxBase a)", "(Control a)", "(RichTextBox a)"};
+			Test("(new RichTextBox())", 3, overloads);
+			Test("(new Control())",     2, overloads);
+			Test("(new TextBox())",     1, overloads);
+			Test("(new Button())",      2, overloads);
+			Test("(3)",                 0, overloads);
+		}
+		
+		[Test] public void Params()
+		{
+			string[] overloads = {"(params int[] a)", "(int a, params int[] b)"};
+			Test("()", 0, overloads);
+			Test("(1)", 1, overloads);
+			Test("(1, 2)", 1, overloads);
+		}
+		
+		[Test] public void IntegerConversion()
+		{
+			string[] overloads = {"<T>(T a)", "(int a)"};
+			Test("(1)", 1, overloads);
+			Test("(short.MaxValue)", 1, overloads);
+			Test("(long.MaxValue)", 0, overloads);
+		}
+		
+		NRefactoryResolverTests nrrt = new NRefactoryResolverTests();
+		
+		void Test(string callExpr, int num, params string[] signatures)
+		{
+			StringBuilder b = new StringBuilder();
+			int lineNumber = 0;
+			++lineNumber; b.AppendLine("using System;");
+			++lineNumber; b.AppendLine("using System.Windows.Forms;");
+			++lineNumber; b.AppendLine("class TestClass {");
+			++lineNumber; b.AppendLine(" void callingMethod() {");
+			++lineNumber; b.AppendLine("   ");
+			int callPosition = lineNumber;
+			++lineNumber; b.AppendLine(" }");
+			int[] positions = new int[signatures.Length];
+			for (int i = 0; i < signatures.Length; i++) {
+				b.Append(" void Method");
+				b.Append(signatures[i]);
+				++lineNumber; b.AppendLine(" {");
+				positions[i] = lineNumber;
+				++lineNumber; b.AppendLine(" }");
+			}
+			b.AppendLine("}");
+			MemberResolveResult mrr = nrrt.Resolve<MemberResolveResult>(b.ToString(), "Method" + callExpr, callPosition);
+			string msg = "wrong overload: ";
+			for (int i = 0; i < positions.Length; i++) {
+				if (positions[i] == mrr.ResolvedMember.Region.BeginLine)
+					msg += signatures[i];
+			}
+			Assert.AreEqual(positions[num], mrr.ResolvedMember.Region.BeginLine, msg);
+		}
+	}
+}