Evaluate constant expressions in definite assignment analysis.

ICSharpCode.NRefactory.Tests/CSharp/Analysis/DefiniteAssignmentTests.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Linq;
+using ICSharpCode.NRefactory.TypeSystem;
 using NUnit.Framework;
 
 namespace ICSharpCode.NRefactory.CSharp.Analysis
@@ -39,7 +40,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 			Statement stmt5 = tryCatchStatement.FinallyBlock.Statements.Single();
 			LabelStatement label = (LabelStatement)block.Statements.ElementAt(1);
 			
-			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(block);
+			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(block, CecilLoaderTests.Mscorlib);
 			da.Analyze("i");
 			Assert.AreEqual(0, da.UnassignedVariableUses.Count);
 			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusBefore(tryCatchStatement));
@@ -89,7 +90,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 				TrueStatement = new BlockStatement(),
 				FalseStatement = new BlockStatement()
 			};
-			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(ifStmt);
+			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(ifStmt, CecilLoaderTests.Mscorlib);
 			da.Analyze("i");
 			Assert.AreEqual(0, da.UnassignedVariableUses.Count);
 			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusBefore(ifStmt));
@@ -120,7 +121,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 				TrueStatement = new BlockStatement(),
 				FalseStatement = new BlockStatement()
 			};
-			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(ifStmt);
+			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(ifStmt, CecilLoaderTests.Mscorlib);
 			da.Analyze("i");
 			Assert.AreEqual(0, da.UnassignedVariableUses.Count);
 			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusBefore(ifStmt));
@@ -128,5 +129,24 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 			Assert.AreEqual(DefiniteAssignmentStatus.DefinitelyAssigned, da.GetStatusBefore(ifStmt.FalseStatement));
 			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusAfter(ifStmt));
 		}
+		
+		[Test]
+		public void WhileTrue()
+		{
+			WhileStatement loop = new WhileStatement {
+				Condition = new PrimitiveExpression(true),
+				EmbeddedStatement = new BlockStatement {
+					new AssignmentExpression(new IdentifierExpression("i"), new PrimitiveExpression(0)),
+					new BreakStatement()
+				}
+			};
+			DefiniteAssignmentAnalysis da = new DefiniteAssignmentAnalysis(loop, CecilLoaderTests.Mscorlib);
+			da.Analyze("i");
+			Assert.AreEqual(0, da.UnassignedVariableUses.Count);
+			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusBefore(loop));
+			Assert.AreEqual(DefiniteAssignmentStatus.PotentiallyAssigned, da.GetStatusBefore(loop.EmbeddedStatement));
+			Assert.AreEqual(DefiniteAssignmentStatus.CodeUnreachable, da.GetStatusAfter(loop.EmbeddedStatement));
+			Assert.AreEqual(DefiniteAssignmentStatus.DefinitelyAssigned, da.GetStatusAfter(loop));
+		}
 	}
 }

ICSharpCode.NRefactory/CSharp/Analysis/ControlFlow.cs

@@ -5,7 +5,10 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Threading;
+
 using ICSharpCode.NRefactory.CSharp.Resolver;
+using ICSharpCode.NRefactory.TypeSystem;
 
 namespace ICSharpCode.NRefactory.CSharp.Analysis
 {
@@ -135,12 +138,24 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		}
 		
 		Statement rootStatement;
+		ResolveVisitor resolveVisitor;
 		List<ControlFlowNode> nodes;
 		Dictionary<string, ControlFlowNode> labels;
 		List<ControlFlowNode> gotoStatements;
 		
-		public IList<ControlFlowNode> BuildControlFlowGraph(Statement statement)
+		public IList<ControlFlowNode> BuildControlFlowGraph(Statement statement, ITypeResolveContext context, CancellationToken cancellationToken = default(CancellationToken))
 		{
+			return BuildControlFlowGraph(statement, new ResolveVisitor(
+				new CSharpResolver(context, cancellationToken), null, ConstantModeResolveVisitorNavigator.Skip));
+		}
+		
+		public IList<ControlFlowNode> BuildControlFlowGraph(Statement statement, ResolveVisitor resolveVisitor)
+		{
+			if (statement == null)
+				throw new ArgumentNullException("statement");
+			if (resolveVisitor == null)
+				throw new ArgumentNullException("resolveVisitor");
+			
 			NodeCreationVisitor nodeCreationVisitor = new NodeCreationVisitor();
 			nodeCreationVisitor.builder = this;
 			try {
@@ -148,6 +163,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 				this.labels = new Dictionary<string, ControlFlowNode>();
 				this.gotoStatements = new List<ControlFlowNode>();
 				this.rootStatement = statement;
+				this.resolveVisitor = resolveVisitor;
 				ControlFlowNode entryPoint = CreateStartNode(statement);
 				statement.AcceptVisitor(nodeCreationVisitor, entryPoint);
 				
@@ -167,6 +183,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 				this.labels = null;
 				this.gotoStatements = null;
 				this.rootStatement = null;
+				this.resolveVisitor = null;
 			}
 		}
 		
@@ -206,7 +223,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		
 		ControlFlowNode CreateSpecialNode(Statement statement, ControlFlowNodeType type)
 		{
-			ControlFlowNode node = CreateNode(statement, null, type);
+			ControlFlowNode node = CreateNode(null, statement, type);
 			nodes.Add(node);
 			return node;
 		}
@@ -238,7 +255,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		/// <returns>The constant value of the expression; or null if the expression is not a constant.</returns>
 		ConstantResolveResult EvaluateConstant(Expression expr)
 		{
-			return null; // TODO: implement this using the C# resolver
+			return resolveVisitor.Resolve(expr) as ConstantResolveResult;
 		}
 		
 		/// <summary>
@@ -256,7 +273,11 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		
 		bool AreEqualConstants(ConstantResolveResult c1, ConstantResolveResult c2)
 		{
-			return false; // TODO: implement this using the resolver's operator==
+			if (c1 == null || c2 == null)
+				return false;
+			CSharpResolver r = new CSharpResolver(resolveVisitor.TypeResolveContext, resolveVisitor.CancellationToken);
+			ResolveResult c = r.ResolveBinaryOperator(BinaryOperatorType.Equality, c1, c2);
+			return c.IsCompileTimeConstant && (c.ConstantValue as bool?) == true;
 		}
 		#endregion
 		

ICSharpCode.NRefactory/CSharp/Analysis/DefiniteAssignmentAnalysis.cs

@@ -5,7 +5,9 @@ using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
+using System.Threading;
 using ICSharpCode.NRefactory.CSharp.Resolver;
+using ICSharpCode.NRefactory.TypeSystem;
 using ICSharpCode.NRefactory.Utils;
 
 namespace ICSharpCode.NRefactory.CSharp.Analysis
@@ -46,6 +48,8 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		readonly List<ControlFlowNode> allNodes = new List<ControlFlowNode>();
 		readonly Dictionary<Statement, ControlFlowNode> beginNodeDict = new Dictionary<Statement, ControlFlowNode>();
 		readonly Dictionary<Statement, ControlFlowNode> endNodeDict = new Dictionary<Statement, ControlFlowNode>();
+		readonly ResolveVisitor resolveVisitor;
+		readonly CancellationToken cancellationToken;
 		Dictionary<ControlFlowNode, DefiniteAssignmentStatus> nodeStatus = new Dictionary<ControlFlowNode, DefiniteAssignmentStatus>();
 		Dictionary<ControlFlowEdge, DefiniteAssignmentStatus> edgeStatus = new Dictionary<ControlFlowEdge, DefiniteAssignmentStatus>();
 		
@@ -54,19 +58,30 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		
 		Queue<ControlFlowNode> nodesWithModifiedInput = new Queue<ControlFlowNode>();
 		
-		public DefiniteAssignmentAnalysis(Statement rootStatement)
+		public DefiniteAssignmentAnalysis(Statement rootStatement, ITypeResolveContext context, CancellationToken cancellationToken = default(CancellationToken))
+			: this(rootStatement, new ResolveVisitor(new CSharpResolver(context, cancellationToken), null, ConstantModeResolveVisitorNavigator.Skip))
 		{
+		}
+		
+		public DefiniteAssignmentAnalysis(Statement rootStatement, ResolveVisitor resolveVisitor)
+		{
+			if (rootStatement == null)
+				throw new ArgumentNullException("rootStatement");
+			if (resolveVisitor == null)
+				throw new ArgumentNullException("resolveVisitor");
+			this.resolveVisitor = resolveVisitor;
+			this.cancellationToken = resolveVisitor.CancellationToken;
 			visitor.analysis = this;
 			ControlFlowGraphBuilder b = new ControlFlowGraphBuilder();
-			allNodes.AddRange(b.BuildControlFlowGraph(rootStatement));
+			allNodes.AddRange(b.BuildControlFlowGraph(rootStatement, resolveVisitor));
 			foreach (AstNode descendant in rootStatement.Descendants) {
 				// Anonymous methods have separate control flow graphs, but we also need to analyze those.
 				AnonymousMethodExpression ame = descendant as AnonymousMethodExpression;
 				if (ame != null)
-					allNodes.AddRange(b.BuildControlFlowGraph(ame.Body));
+					allNodes.AddRange(b.BuildControlFlowGraph(ame.Body, resolveVisitor));
 				LambdaExpression lambda = descendant as LambdaExpression;
 				if (lambda != null && lambda.Body is Statement)
-					allNodes.AddRange(b.BuildControlFlowGraph((Statement)lambda.Body));
+					allNodes.AddRange(b.BuildControlFlowGraph((Statement)lambda.Body, resolveVisitor));
 			}
 			// Verify that we created nodes for all statements:
 			Debug.Assert(!rootStatement.DescendantsAndSelf.OfType<Statement>().Except(allNodes.Select(n => n.NextStatement)).Any());
@@ -289,7 +304,7 @@ namespace ICSharpCode.NRefactory.CSharp.Analysis
 		/// <returns>The constant value of the expression; or null if the expression is not a constant.</returns>
 		ConstantResolveResult EvaluateConstant(Expression expr)
 		{
-			return null; // TODO: implement this using the C# resolver
+			return resolveVisitor.Resolve(expr) as ConstantResolveResult;
 		}
 		
 		/// <summary>

ICSharpCode.NRefactory/CSharp/Ast/AstNode.cs

@@ -129,6 +129,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			get {
 				AstNode next;
 				for (AstNode cur = firstChild; cur != null; cur = next) {
+					Debug.Assert(cur.parent == this);
 					// Remember next before yielding cur.
 					// This allows removing/replacing nodes while iterating through the list.
 					next = cur.nextSibling;

ICSharpCode.NRefactory/CSharp/Ast/AstNodeCollection.cs

@@ -117,6 +117,7 @@ namespace ICSharpCode.NRefactory.CSharp
 		{
 			AstNode next;
 			for (AstNode cur = node.FirstChild; cur != null; cur = next) {
+				Debug.Assert(cur.Parent == node);
 				// Remember next before yielding cur.
 				// This allows removing/replacing nodes while iterating through the list.
 				next = cur.NextSibling;

ICSharpCode.NRefactory/CSharp/Parser/CSharpParser.cs

@@ -374,9 +374,9 @@ namespace ICSharpCode.NRefactory.CSharp
 				variable.AddChild (new Identifier (em.Name, Convert (em.Location)), AstNode.Roles.Identifier);
 				
 				if (em.Initializer != null) {
-					var initializer = (VariableInitializer)em.Initializer.Accept (this);
+					var initializer = (Expression)em.Initializer.Accept (this);
 					if (initializer != null)
-						variable.AddChild (initializer, AstNode.Roles.Variable);
+						variable.AddChild (initializer, EnumMemberDeclaration.InitializerRole);
 				}
 				
 				newField.AddChild (variable, AstNode.Roles.Variable);

ICSharpCode.NRefactory/CSharp/Resolver/CSharpResolver.cs

@@ -33,7 +33,6 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			this.context = context;
 		}
 		
-		#if !DOTNET35
 		public CSharpResolver(ITypeResolveContext context, CancellationToken cancellationToken)
 		{
 			if (context == null)
@@ -41,7 +40,6 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			this.context = context;
 			this.cancellationToken = cancellationToken;
 		}
-		#endif
 		#endregion
 		
 		#region Properties

ICSharpCode.NRefactory/CSharp/Resolver/IResolveVisitorNavigator.cs

@@ -37,4 +37,16 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		/// </summary>
 		ResolveAll
 	}
+	
+	sealed class ConstantModeResolveVisitorNavigator : IResolveVisitorNavigator
+	{
+		ResolveVisitorNavigationMode mode;
+		
+		public static readonly IResolveVisitorNavigator Skip = new ConstantModeResolveVisitorNavigator { mode = ResolveVisitorNavigationMode.Skip };
+		
+		ResolveVisitorNavigationMode IResolveVisitorNavigator.Scan(AstNode node)
+		{
+			return mode;
+		}
+	}
 }

ICSharpCode.NRefactory/CSharp/Resolver/ResolveVisitor.cs

@@ -74,6 +74,20 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		}
 		#endregion
 		
+		/// <summary>
+		/// Gets the TypeResolveContext used by this ResolveVisitor.
+		/// </summary>
+		public ITypeResolveContext TypeResolveContext {
+			get { return resolver.Context; }
+		}
+		
+		/// <summary>
+		/// Gets the CancellationToken used by this ResolveVisitor.
+		/// </summary>
+		public CancellationToken CancellationToken {
+			get { return resolver.cancellationToken; }
+		}
+		
 		#region Scan / Resolve
 		bool resolverEnabled {
 			get { return mode != ResolveVisitorNavigationMode.Scan; }
@@ -118,6 +132,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				mode = ResolveVisitorNavigationMode.Resolve;
 			ResolveResult result;
 			if (!cache.TryGetValue(node, out result)) {
+				resolver.cancellationToken.ThrowIfCancellationRequested();
 				result = cache[node] = node.AcceptVisitor(this, null) ?? errorResult;
 			}
 			if (wasScan)