Merge pull request #2814 from mattwar/Bug864402

Guard visitors against stack overflow exceptions

src/Compilers/CSharp/Portable/Parser/LanguageParser.cs

@@ -25,7 +25,7 @@ internal partial class LanguageParser : SyntaxParser
         //  2. A modified version of the parser was run on the Roslyn source base and the maximum depth 
         //     discovered was 7.  Having 20 as a minimum seems reasonable in that context 
         //
-        private const int MaxUncheckedRecursionDepth = 20;
+        internal const int MaxUncheckedRecursionDepth = 20;
 
         // list pools - allocators for lists that are used to build sequences of nodes. The lists
         // can be reused (hence pooled) since the syntax factory methods don't keep references to

src/Compilers/CSharp/Portable/PublicAPI.txt

@@ -2522,6 +2522,7 @@ override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxNode.ReplaceTriviaInListCore(
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxNode.SerializeTo(System.IO.Stream stream, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken)) -> void
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxNode.SyntaxTreeCore.get -> Microsoft.CodeAnalysis.SyntaxTree
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxNode.WriteTo(System.IO.TextWriter writer) -> void
+override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxRewriter.Visit(Microsoft.CodeAnalysis.SyntaxNode node) -> Microsoft.CodeAnalysis.SyntaxNode
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxRewriter.VisitAccessorDeclaration(Microsoft.CodeAnalysis.CSharp.Syntax.AccessorDeclarationSyntax node) -> Microsoft.CodeAnalysis.SyntaxNode
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxRewriter.VisitAccessorList(Microsoft.CodeAnalysis.CSharp.Syntax.AccessorListSyntax node) -> Microsoft.CodeAnalysis.SyntaxNode
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxRewriter.VisitAliasQualifiedName(Microsoft.CodeAnalysis.CSharp.Syntax.AliasQualifiedNameSyntax node) -> Microsoft.CodeAnalysis.SyntaxNode
@@ -2726,6 +2727,7 @@ override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.OptionsCore.get -> Micro
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.TryGetRootCore(out Microsoft.CodeAnalysis.SyntaxNode root) -> bool
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxTree.WithChangedText(Microsoft.CodeAnalysis.Text.SourceText newText) -> Microsoft.CodeAnalysis.SyntaxTree
 override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxWalker.DefaultVisit(Microsoft.CodeAnalysis.SyntaxNode node) -> void
+override Microsoft.CodeAnalysis.CSharp.CSharpSyntaxWalker.Visit(Microsoft.CodeAnalysis.SyntaxNode node) -> void
 override Microsoft.CodeAnalysis.CSharp.Conversion.Equals(object obj) -> bool
 override Microsoft.CodeAnalysis.CSharp.Conversion.GetHashCode() -> int
 override Microsoft.CodeAnalysis.CSharp.Conversion.ToString() -> string

src/Compilers/CSharp/Portable/Syntax/CSharpSyntaxRewriter.cs

@@ -5,6 +5,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Text;
 using System;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {
@@ -26,6 +27,29 @@ public virtual bool VisitIntoStructuredTrivia
             get { return _visitIntoStructuredTrivia; }
         }
 
+        private int _recursionDepth;
+
+        public override SyntaxNode Visit(SyntaxNode node)
+        {
+            if (node != null)
+            {
+                _recursionDepth++;
+                if (_recursionDepth > Syntax.InternalSyntax.LanguageParser.MaxUncheckedRecursionDepth)
+                {
+                    PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack();
+                }
+
+                var result = ((CSharpSyntaxNode)node).Accept(this);
+
+                _recursionDepth--;
+                return result;
+            }
+            else
+            {
+                return null;
+            }
+        }
+
         public virtual SyntaxToken VisitToken(SyntaxToken token)
         {
             // PERF: This is a hot method, so it has been written to minimize the following:

src/Compilers/CSharp/Portable/Syntax/CSharpSyntaxVisitor.cs

@@ -3,6 +3,7 @@
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Text;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {

src/Compilers/CSharp/Portable/Syntax/CSharpSyntaxWalker.cs

@@ -4,6 +4,7 @@
 using Microsoft.CodeAnalysis.CSharp.Symbols;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Text;
+using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp
 {
@@ -20,6 +21,24 @@ protected CSharpSyntaxWalker(SyntaxWalkerDepth depth = SyntaxWalkerDepth.Node)
             this.Depth = depth;
         }
 
+        private int _recursionDepth;
+
+        public override void Visit(SyntaxNode node)
+        {
+            if (node != null)
+            {
+                _recursionDepth++;
+                if (_recursionDepth > Syntax.InternalSyntax.LanguageParser.MaxUncheckedRecursionDepth)
+                {
+                    PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack();
+                }
+
+                ((CSharpSyntaxNode)node).Accept(this);
+
+                _recursionDepth--;
+            }
+        }
+
         public override void DefaultVisit(SyntaxNode node)
         {
             var childCnt = node.ChildNodesAndTokens().Count;

src/Compilers/VisualBasic/Portable/BasicCodeAnalysis.vbproj

@@ -930,6 +930,7 @@
     <Compile Include="Syntax\LambdaUtilities.vb" />
     <Compile Include="Syntax\TypeBlockSyntax.vb" />
     <Compile Include="Syntax\TypeStatementSyntax.vb" />
+    <Compile Include="Syntax\VisualBasicSyntaxVisitor.vb" />
     <Compile Include="Syntax\VisualBasicWarningStateMap.vb" />
     <Compile Include="Syntax\VisualBasicLineDirectiveMap.vb" />
     <Compile Include="Syntax\VisualBasicSyntaxNode.vb" />
@@ -1033,4 +1034,4 @@
     <Import Project="..\..\..\..\build\VSL.Imports.Closed.targets" />
     <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
   </ImportGroup>
-</Project>
+</Project>
\ No newline at end of file

src/Compilers/VisualBasic/Portable/Parser/ParseExpression.vb

@@ -50,7 +50,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
 
             Try
                 _recursionDepth += 1
-                If _recursionDepth >= _maxUncheckedRecursionDepth Then
+                If _recursionDepth >= MaxUncheckedRecursionDepth Then
                     PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack()
                 End If
 

src/Compilers/VisualBasic/Portable/Parser/Parser.vb

@@ -21,7 +21,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
         End Enum
 
         ' Keep this value in sync with C# LanguageParser
-        Private Const _maxUncheckedRecursionDepth As Integer = 30
+        Friend Const MaxUncheckedRecursionDepth As Integer = 20
 
         Private _allowLeadingMultilineTrivia As Boolean = True
         Private _hadImplicitLineContinuation As Boolean = False
@@ -856,7 +856,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
 
             Try
                 _recursionDepth += 1
-                If _recursionDepth >= _maxUncheckedRecursionDepth Then
+                If _recursionDepth >= MaxUncheckedRecursionDepth Then
                     PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack()
                 End If
 

src/Compilers/VisualBasic/Portable/PublicAPI.txt

@@ -4437,6 +4437,7 @@ Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxNode.ReplaceTrivia
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxNode.SerializeTo(stream As System.IO.Stream, cancellationToken As System.Threading.CancellationToken = Nothing) -> Void
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxNode.SyntaxTreeCore() -> Microsoft.CodeAnalysis.SyntaxTree
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxNode.WriteTo(writer As System.IO.TextWriter) -> Void
+Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxRewriter.Visit(node As Microsoft.CodeAnalysis.SyntaxNode) -> Microsoft.CodeAnalysis.SyntaxNode
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxRewriter.VisitAccessorBlock(node As Microsoft.CodeAnalysis.VisualBasic.Syntax.AccessorBlockSyntax) -> Microsoft.CodeAnalysis.SyntaxNode
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxRewriter.VisitAccessorStatement(node As Microsoft.CodeAnalysis.VisualBasic.Syntax.AccessorStatementSyntax) -> Microsoft.CodeAnalysis.SyntaxNode
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxRewriter.VisitAddRemoveHandlerStatement(node As Microsoft.CodeAnalysis.VisualBasic.Syntax.AddRemoveHandlerStatementSyntax) -> Microsoft.CodeAnalysis.SyntaxNode
@@ -4696,6 +4697,7 @@ Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxTree.OptionsCore()
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxTree.TryGetRootCore(ByRef root As Microsoft.CodeAnalysis.SyntaxNode) -> Boolean
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxTree.WithChangedText(newText As Microsoft.CodeAnalysis.Text.SourceText) -> Microsoft.CodeAnalysis.SyntaxTree
 Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxWalker.DefaultVisit(node As Microsoft.CodeAnalysis.SyntaxNode) -> Void
+Overrides Microsoft.CodeAnalysis.VisualBasic.VisualBasicSyntaxWalker.Visit(node As Microsoft.CodeAnalysis.SyntaxNode) -> Void
 ReadOnly Microsoft.CodeAnalysis.VisualBasic.AggregateClauseSymbolInfo.Select1 -> Microsoft.CodeAnalysis.SymbolInfo
 ReadOnly Microsoft.CodeAnalysis.VisualBasic.AggregateClauseSymbolInfo.Select2 -> Microsoft.CodeAnalysis.SymbolInfo
 ReadOnly Microsoft.CodeAnalysis.VisualBasic.CollectionRangeVariableSymbolInfo.AsClauseConversion -> Microsoft.CodeAnalysis.SymbolInfo

src/Compilers/VisualBasic/Portable/Syntax/VisualBasicSyntaxRewriter.vb

@@ -29,6 +29,25 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End Get
         End Property
 
+        Private _recursionDepth As Integer
+
+        Public Overrides Function Visit(node As SyntaxNode) As SyntaxNode
+            If node IsNot Nothing Then
+                _recursionDepth += 1
+
+                If _recursionDepth > Syntax.InternalSyntax.Parser.MaxUncheckedRecursionDepth Then
+                    PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack()
+                End If
+
+                Dim result = DirectCast(node, VisualBasicSyntaxNode).Accept(Me)
+
+                _recursionDepth -= 1
+                Return result
+            Else
+                Return node
+            End If
+        End Function
+
         Public Overridable Function VisitToken(token As SyntaxToken) As SyntaxToken
             Dim leading = Me.VisitList(token.LeadingTrivia)
             Dim trailing = Me.VisitList(token.TrailingTrivia)

src/Compilers/VisualBasic/Portable/Syntax/VisualBasicSyntaxVisitor.vb

+' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+Imports Microsoft.CodeAnalysis.Text
+Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
+Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
+
+Namespace Microsoft.CodeAnalysis.VisualBasic
+    ''' <summary>
+    ''' Represents a <see cref="SyntaxNode"/> visitor that visits only the single SyntaxNode
+    ''' passed into its <see cref="Visit(SyntaxNode)"/> method.
+    ''' </summary>
+    Partial Public MustInherit Class VisualBasicSyntaxVisitor
+
+        Public Overridable Sub Visit(ByVal node As SyntaxNode)
+            If node IsNot Nothing Then
+                DirectCast(node, VisualBasicSyntaxNode).Accept(Me)
+            End If
+        End Sub
+
+        Public Overridable Sub DefaultVisit(ByVal node As SyntaxNode)
+        End Sub
+    End Class
+
+    ''' <summary>
+    ''' Represents a <see cref="SyntaxNode"/> visitor that visits only the single SyntaxNode
+    ''' passed into its <see cref="Visit(SyntaxNode)"/> method and produces 
+    ''' a value of the type specified by the <typeparamref name="TResult"/> parameter.
+    ''' </summary>
+    ''' <typeparam name="TResult">
+    ''' The type of the return value of this visitor's Visit method.
+    ''' </typeparam>
+    Partial Public MustInherit Class VisualBasicSyntaxVisitor(Of TResult)
+
+        Public Overridable Function Visit(ByVal node As SyntaxNode) As TResult
+            If node IsNot Nothing Then
+                Return DirectCast(node, VisualBasicSyntaxNode).Accept(Me)
+            End If
+
+            Return Nothing
+        End Function
+
+        Public Overridable Function DefaultVisit(ByVal node As SyntaxNode) As TResult
+            Return Nothing
+        End Function
+    End Class
+End Namespace

src/Compilers/VisualBasic/Portable/Syntax/VisualBasicSyntaxWalker.vb

@@ -18,6 +18,22 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             Me.Depth = depth
         End Sub
 
+        Private _recursionDepth As Integer
+
+        Public Overrides Sub Visit(node As SyntaxNode)
+            If node IsNot Nothing Then
+                _recursionDepth += 1
+
+                If _recursionDepth > Syntax.InternalSyntax.Parser.MaxUncheckedRecursionDepth Then
+                    PortableShim.RuntimeHelpers.EnsureSufficientExecutionStack()
+                End If
+
+                DirectCast(node, VisualBasicSyntaxNode).Accept(Me)
+
+                _recursionDepth -= 1
+            End If
+        End Sub
+
         Public Overrides Sub DefaultVisit(node As SyntaxNode)
             Dim list = node.ChildNodesAndTokens()
             Dim childCnt = list.Count
@@ -70,22 +86,4 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
             End If
         End Sub
     End Class
-
-    ''' <summary>
-    ''' Represents a <see cref="SyntaxNode"/> visitor that visits only the single SyntaxNode
-    ''' passed into its <see cref="Visit(SyntaxNode)"/> method.
-    ''' </summary>
-    Partial Public MustInherit Class VisualBasicSyntaxVisitor
-    End Class
-
-    ''' <summary>
-    ''' Represents a <see cref="SyntaxNode"/> visitor that visits only the single SyntaxNode
-    ''' passed into its <see cref="Visit(SyntaxNode)"/> method and produces 
-    ''' a value of the type specified by the <typeparamref name="TResult"/> parameter.
-    ''' </summary>
-    ''' <typeparam name="TResult">
-    ''' The type of the return value this visitor's Visit method.
-    ''' </typeparam>
-    Partial Public MustInherit Class VisualBasicSyntaxVisitor(Of TResult)
-    End Class
 End Namespace

src/Tools/Source/CompilerGeneratorTools/Source/VisualBasicSyntaxGenerator/RedNodes/RedNodeWriter.vb

@@ -1032,22 +1032,6 @@ Friend Class RedNodeWriter
     Private Sub GenerateVisitorClass(withResult As Boolean)
         _writer.WriteLine("    Public MustInherit Class {0}{1}", Ident(_parseTree.VisitorName), If(withResult, "(Of TResult)", ""))
 
-        ' Basic Visit method that dispatches.
-        _writer.WriteLine("        Public Overridable {0} Visit(ByVal node As SyntaxNode){1}",
-                          If(withResult, "Function", "Sub"),
-                          If(withResult, " As TResult", ""))
-        _writer.WriteLine("            If node Is Nothing")
-        _writer.WriteLine("                Return{0}", If(withResult, " Nothing", ""))
-        _writer.WriteLine("            End If")
-        _writer.WriteLine("")
-        _writer.WriteLine("            {0}DirectCast(node, VisualBasicSyntaxNode).Accept(Me){1}", If(withResult, "Return ", ""), If(withResult, "", ": Return"))
-        _writer.WriteLine("        End {0}", If(withResult, "Function", "Sub"))
-
-        _writer.WriteLine("        Public Overridable {0} DefaultVisit(ByVal node As SyntaxNode){1}",
-                          If(withResult, "Function", "Sub"),
-                          If(withResult, " As TResult", ""))
-        _writer.WriteLine("        End {0}", If(withResult, "Function", "Sub"))
-
         For Each nodeStructure In _parseTree.NodeStructures.Values
             If Not nodeStructure.Abstract Then
                 GenerateVisitorMethod(nodeStructure, withResult)