C#: Refactoring expression and statement population.

csharp/extractor/Semmle.Extraction.CIL/Id.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using System.IO;
 using System.Reflection.Metadata;
 
 namespace Semmle.Extraction.CIL

csharp/extractor/Semmle.Extraction.CSharp.Driver/Semmle.Extraction.CSharp.Driver.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>

csharp/extractor/Semmle.Extraction.CSharp/Entities/Accessor.cs

@@ -30,9 +30,9 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public new Accessor OriginalDefinition => Create(Context, symbol.OriginalDefinition);
 
-        public override void Populate()
+        public override void Populate(System.IO.TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ExtractModifiers();
             ContainingType.ExtractGenerics();
 
@@ -62,16 +62,16 @@ namespace Semmle.Extraction.CSharp.Entities
                 return;
             }
 
-            Context.Emit(Tuples.accessors(this, kind, symbol.Name, parent, unboundAccessor));
+            trapFile.Emit(Tuples.accessors(this, kind, symbol.Name, parent, unboundAccessor));
 
             foreach (var l in Locations)
-                Context.Emit(Tuples.accessor_location(this, l));
+                trapFile.Emit(Tuples.accessor_location(this, l));
 
-            Overrides();
+            Overrides(trapFile);
 
             if (symbol.FromSource() && Block == null)
             {
-                Context.Emit(Tuples.compiler_generated(this));
+                trapFile.Emit(Tuples.compiler_generated(this));
             }
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Attribute.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities
@@ -11,17 +12,27 @@ namespace Semmle.Extraction.CSharp.Entities
     {
         bool IExpressionParentEntity.IsTopLevelParent => true;
 
+        private readonly AttributeData AttributeData;
+        private readonly IEntity Entity;
+
         public Attribute(Context cx, AttributeData attribute, IEntity entity)
             : base(cx)
         {
-            if (attribute.ApplicationSyntaxReference != null)
+            AttributeData = attribute;
+            Entity = entity;
+            TryPopulate();
+        }
+
+        protected override void Populate(TextWriter trapFile)
+        {
+            if (AttributeData.ApplicationSyntaxReference != null)
             {
                 // !! Extract attributes from assemblies.
                 // This is harder because the "expression" entities presume the
                 // existence of a syntax tree. This is not the case for compiled
                 // attributes.
-                var syntax = attribute.ApplicationSyntaxReference.GetSyntax() as AttributeSyntax;
+                var syntax = AttributeData.ApplicationSyntaxReference.GetSyntax() as AttributeSyntax;
-                ExtractAttribute(syntax, attribute.AttributeClass, entity);
+                ExtractAttribute(cx.TrapWriter.Writer, syntax, AttributeData.AttributeClass, Entity);
             }
         }
 
@@ -29,18 +40,18 @@ namespace Semmle.Extraction.CSharp.Entities
             : base(cx)
         {
             var info = cx.GetSymbolInfo(attribute);
-            ExtractAttribute(attribute, info.Symbol.ContainingType, entity);
+            ExtractAttribute(cx.TrapWriter.Writer, attribute, info.Symbol.ContainingType, entity);
         }
 
-        void ExtractAttribute(AttributeSyntax syntax, ITypeSymbol attributeClass, IEntity entity)
+        void ExtractAttribute(System.IO.TextWriter trapFile, AttributeSyntax syntax, ITypeSymbol attributeClass, IEntity entity)
         {
             var type = Type.Create(cx, attributeClass);
-            cx.Emit(Tuples.attributes(this, type.TypeRef, entity));
+            trapFile.Emit(Tuples.attributes(this, type.TypeRef, entity));
 
-            cx.Emit(Tuples.attribute_location(this, cx.Create(syntax.Name.GetLocation())));
+            trapFile.Emit(Tuples.attribute_location(this, cx.Create(syntax.Name.GetLocation())));
 
             if (cx.Extractor.OutputPath != null)
-                cx.Emit(Tuples.attribute_location(this, Assembly.CreateOutputAssembly(cx)));
+                trapFile.Emit(Tuples.attribute_location(this, Assembly.CreateOutputAssembly(cx)));
 
             TypeMention.Create(cx, syntax.Name, this, type);
 
@@ -54,7 +65,7 @@ namespace Semmle.Extraction.CSharp.Entities
                         var expr = Expression.Create(cx, arg.Expression, this, child++);
                         if (!(arg.NameEquals is null))
                         {
-                            cx.Emit(Tuples.expr_argument_name(expr, arg.NameEquals.Name.Identifier.Text));
+                            trapFile.Emit(Tuples.expr_argument_name(expr, arg.NameEquals.Name.Identifier.Text));
                         }
                     }
                 });

csharp/extractor/Semmle.Extraction.CSharp/Entities/CommentBlock.cs

@@ -9,14 +9,14 @@ namespace Semmle.Extraction.CSharp.Entities
         CommentBlock(Context cx, ICommentBlock init)
             : base(cx, init) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.commentblock(this));
+            trapFile.Emit(Tuples.commentblock(this));
             int child = 0;
-            Context.Emit(Tuples.commentblock_location(this, Context.Create(symbol.Location)));
+            trapFile.Emit(Tuples.commentblock_location(this, Context.Create(symbol.Location)));
             foreach (var l in symbol.CommentLines)
             {
-                Context.Emit(Tuples.commentblock_child(this, (CommentLine)l, child++));
+                trapFile.Emit(Tuples.commentblock_child(this, (CommentLine)l, child++));
             }
         }
 
@@ -32,7 +32,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public void BindTo(Label entity, CommentBinding binding)
         {
-            Context.Emit(Tuples.commentblock_binding(this, entity, binding));
+            Context.TrapWriter.Writer.Emit(Tuples.commentblock_binding(this, entity, binding));
         }
 
         public static CommentBlock Create(Context cx, ICommentBlock block) => CommentBlockFactory.Instance.CreateEntity(cx, block);

csharp/extractor/Semmle.Extraction.CSharp/Entities/CommentLine.cs

@@ -112,11 +112,11 @@ namespace Semmle.Extraction.CSharp.Entities
 
         Extraction.Entities.Location location;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             location = Context.Create(Location);
-            Context.Emit(Tuples.commentline(this, Type == CommentLineType.MultilineContinuation ? CommentLineType.Multiline : Type, Text, RawText));
+            trapFile.Emit(Tuples.commentline(this, Type == CommentLineType.MultilineContinuation ? CommentLineType.Multiline : Type, Text, RawText));
-            Context.Emit(Tuples.commentline_location(this, location));
+            trapFile.Emit(Tuples.commentline_location(this, location));
         }
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation => location.symbol;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Compilation.cs

@@ -1,57 +1,67 @@
 using Microsoft.CodeAnalysis;
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
+using System.IO;
 using System.Linq;
-using System.Text;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
     class Compilation : FreshEntity
     {
+        string cwd;
+        string[] args;
+
         public Compilation(Context cx, string cwd, string[] args) : base(cx)
+        {
+            this.cwd = cwd;
+            this.args = args;
+            TryPopulate();
+        }
+
+        protected override void Populate(TextWriter trapFile)
         {
             Extraction.Entities.Assembly.CreateOutputAssembly(cx);
 
-            cx.Emit(Tuples.compilations(this, Extraction.Entities.File.PathAsDatabaseString(cwd)));
+            trapFile.Emit(Tuples.compilations(this, Extraction.Entities.File.PathAsDatabaseString(cwd)));
 
             // Arguments
             int index = 0;
             foreach(var arg in args)
             {
-                cx.Emit(Tuples.compilation_args(this, index++, arg));
+                trapFile.Emit(Tuples.compilation_args(this, index++, arg));
             }
 
             // Files
             index = 0;
             foreach(var file in cx.Compilation.SyntaxTrees.Select(tree => Extraction.Entities.File.Create(cx, tree.FilePath)))
             {
-                cx.Emit(Tuples.compilation_compiling_files(this, index++, file));
+                trapFile.Emit(Tuples.compilation_compiling_files(this, index++, file));
             }
 
             // References
             index = 0;
             foreach(var file in cx.Compilation.References.OfType<PortableExecutableReference>().Select(r => Extraction.Entities.File.Create(cx, r.FilePath)))
             {
-                cx.Emit(Tuples.compilation_referencing_files(this, index++, file));
+                trapFile.Emit(Tuples.compilation_referencing_files(this, index++, file));
             }
 
             // Diagnostics
             index = 0;
             foreach(var diag in cx.Compilation.GetDiagnostics().Select(d => new Diagnostic(cx, d)))
             {
-                cx.Emit(Tuples.diagnostic_for(diag, this, 0, index++));
+                trapFile.Emit(Tuples.diagnostic_for(diag, this, 0, index++));
             }
         }
 
         public void PopulatePerformance(PerformanceMetrics p)
         {
+            var trapFile = cx.TrapWriter.Writer;
             int index = 0;
             foreach(float metric in p.Metrics)
             {
-                cx.Emit(Tuples.compilation_time(this, -1, index++, metric));
+                trapFile.Emit(Tuples.compilation_time(this, -1, index++, metric));
             }
-            cx.Emit(Tuples.compilation_finished(this, (float)p.Total.Cpu.TotalSeconds, (float)p.Total.Elapsed.TotalSeconds));
+            trapFile.Emit(Tuples.compilation_finished(this, (float)p.Total.Cpu.TotalSeconds, (float)p.Total.Elapsed.TotalSeconds));
         }
 
         public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.NoLabel;
@@ -61,10 +71,18 @@ namespace Semmle.Extraction.CSharp.Entities
     {
         public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.NoLabel;
 
+        readonly Microsoft.CodeAnalysis.Diagnostic diagnostic;
+
         public Diagnostic(Context cx, Microsoft.CodeAnalysis.Diagnostic diag) : base(cx)
         {
-            cx.Emit(Tuples.diagnostics(this, (int)diag.Severity, diag.Id, diag.Descriptor.Title.ToString(),
+            diagnostic = diag;
-                diag.GetMessage(), Extraction.Entities.Location.Create(cx, diag.Location)));
+            TryPopulate();
+        }
+
+        protected override void Populate(TextWriter trapFile)
+        {
+            trapFile.Emit(Tuples.diagnostics(this, (int)diagnostic.Severity, diagnostic.Id, diagnostic.Descriptor.Title.ToString(),
+                diagnostic.GetMessage(), Extraction.Entities.Location.Create(cx, diagnostic.Location)));
         }
     }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Constructor.cs

@@ -14,24 +14,24 @@ namespace Semmle.Extraction.CSharp.Entities
         Constructor(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ExtractModifiers();
             ContainingType.ExtractGenerics();
 
-            Context.Emit(Tuples.constructors(this, symbol.ContainingType.Name, ContainingType, (Constructor)OriginalDefinition));
+            trapFile.Emit(Tuples.constructors(this, symbol.ContainingType.Name, ContainingType, (Constructor)OriginalDefinition));
-            Context.Emit(Tuples.constructor_location(this, Location));
+            trapFile.Emit(Tuples.constructor_location(this, Location));
 
             if (symbol.IsImplicitlyDeclared)
             {
                 var lineCounts = new LineCounts() { Total = 2, Code = 1, Comment = 0 };
-                Context.Emit(Tuples.numlines(this, lineCounts));
+                trapFile.Emit(Tuples.numlines(this, lineCounts));
             }
-            ExtractCompilerGenerated();
+            ExtractCompilerGenerated(trapFile);
         }
 
-        protected override void ExtractInitializers()
+        protected override void ExtractInitializers(TextWriter trapFile)
         {
             // Do not extract initializers for constructed types.
             if (!IsSourceDeclaration) return;
@@ -76,7 +76,7 @@ namespace Semmle.Extraction.CSharp.Entities
                 return;
             }
 
-            Context.Emit(Tuples.expr_call(init, target));
+            trapFile.Emit(Tuples.expr_call(init, target));
 
             int child = 0;
             foreach (var arg in initializer.ArgumentList.Arguments)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Destructor.cs

@@ -1,4 +1,5 @@
 using Microsoft.CodeAnalysis;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
@@ -7,14 +8,14 @@ namespace Semmle.Extraction.CSharp.Entities
         Destructor(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ExtractModifiers();
             ContainingType.ExtractGenerics();
 
-            Context.Emit(Tuples.destructors(this, string.Format("~{0}", symbol.ContainingType.Name), ContainingType, OriginalDefinition(Context, this, symbol)));
+            trapFile.Emit(Tuples.destructors(this, string.Format("~{0}", symbol.ContainingType.Name), ContainingType, OriginalDefinition(Context, this, symbol)));
-            Context.Emit(Tuples.destructor_location(this, Location));
+            trapFile.Emit(Tuples.destructor_location(this, Location));
         }
 
         static new Destructor OriginalDefinition(Context cx, Destructor original, IMethodSymbol symbol)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Event.cs

@@ -19,9 +19,9 @@ namespace Semmle.Extraction.CSharp.Entities
             trapFile.Write(";event");
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            ExtractNullability(symbol.NullableAnnotation);
+            ExtractNullability(trapFile, symbol.NullableAnnotation);
 
             var type = Type.Create(Context, symbol.Type);
             Context.Emit(Tuples.events(this, symbol.GetName(), ContainingType, type.TypeRef, Create(Context, symbol.OriginalDefinition)));
@@ -44,14 +44,14 @@ namespace Semmle.Extraction.CSharp.Entities
 
             foreach (var explicitInterface in symbol.ExplicitInterfaceImplementations.Select(impl => Type.Create(Context, impl.ContainingType)))
             {
-                Context.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
+                trapFile.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
 
                 foreach (var syntax in declSyntaxReferences.OfType<EventDeclarationSyntax>())
                     TypeMention.Create(Context, syntax.ExplicitInterfaceSpecifier.Name, this, explicitInterface);
             }
 
             foreach (var l in Locations)
-                Context.Emit(Tuples.event_location(this, l));
+                trapFile.Emit(Tuples.event_location(this, l));
 
             foreach (var syntaxType in declSyntaxReferences.OfType<VariableDeclaratorSyntax>().
                 Select(d => d.Parent).

csharp/extractor/Semmle.Extraction.CSharp/Entities/EventAccessor.cs

@@ -1,4 +1,5 @@
 using Microsoft.CodeAnalysis;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
@@ -12,9 +13,9 @@ namespace Semmle.Extraction.CSharp.Entities
         /// </summary>
         IEventSymbol EventSymbol => symbol.AssociatedSymbol as IEventSymbol;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ContainingType.ExtractGenerics();
 
             var @event = EventSymbol;
@@ -43,12 +44,12 @@ namespace Semmle.Extraction.CSharp.Entities
                 return;
             }
 
-            Context.Emit(Tuples.event_accessors(this, kind, symbol.Name, parent, unboundAccessor));
+            trapFile.Emit(Tuples.event_accessors(this, kind, symbol.Name, parent, unboundAccessor));
 
             foreach (var l in Locations)
-                Context.Emit(Tuples.event_accessor_location(this, l));
+                trapFile.Emit(Tuples.event_accessor_location(this, l));
 
-            Overrides();
+            Overrides(trapFile);
         }
 
         public new static EventAccessor Create(Context cx, IMethodSymbol symbol) =>

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expression.cs

@@ -4,6 +4,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities
@@ -18,6 +19,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
     class Expression : FreshEntity, IExpressionParentEntity
     {
+        private readonly IExpressionInfo Info;
         public readonly AnnotatedType Type;
         public readonly Extraction.Entities.Location Location;
         public readonly ExprKind Kind;
@@ -25,24 +27,29 @@ namespace Semmle.Extraction.CSharp.Entities
         internal Expression(IExpressionInfo info)
             : base(info.Context)
         {
+            Info = info;
             Location = info.Location;
             Kind = info.Kind;
             Type = info.Type;
-
             if (Type.Type is null)
                 Type = NullType.Create(cx);
 
-            cx.Emit(Tuples.expressions(this, Kind, Type.Type.TypeRef));
+            TryPopulate();
-            if (info.Parent.IsTopLevelParent)
+        }
-                cx.Emit(Tuples.expr_parent_top_level(this, info.Child, info.Parent));
+
+        protected sealed override void Populate(TextWriter trapFile)
+        {
+            trapFile.Emit(Tuples.expressions(this, Kind, Type.Type.TypeRef));
+            if (Info.Parent.IsTopLevelParent)
+                trapFile.Emit(Tuples.expr_parent_top_level(this, Info.Child, Info.Parent));
             else
-                cx.Emit(Tuples.expr_parent(this, info.Child, info.Parent));
+                trapFile.Emit(Tuples.expr_parent(this, Info.Child, Info.Parent));
-            cx.Emit(Tuples.expr_location(this, Location));
+            trapFile.Emit(Tuples.expr_location(this, Location));
 
-            if (info.IsCompilerGenerated)
+            if (Info.IsCompilerGenerated)
-                cx.Emit(Tuples.expr_compiler_generated(this));
+                trapFile.Emit(Tuples.expr_compiler_generated(this));
 
-            if (info.ExprValue is string value)
+            if (Info.ExprValue is string value)
                 cx.Emit(Tuples.expr_value(this, value));
 
             Type.Type.ExtractGenerics();
@@ -117,21 +124,20 @@ namespace Semmle.Extraction.CSharp.Entities
         /// </summary>
         /// <param name="cx">Context</param>
         /// <param name="node">The expression.</param>
-        public void OperatorCall(ExpressionSyntax node)
+        public void OperatorCall(TextWriter trapFile, ExpressionSyntax node)
         {
             var @operator = cx.GetSymbolInfo(node);
             if (@operator.Symbol is IMethodSymbol method)
             {
-
                 var callType = GetCallType(cx, node);
                 if (callType == CallType.Dynamic)
                 {
                     UserOperator.OperatorSymbol(method.Name, out string operatorName);
-                    cx.Emit(Tuples.dynamic_member_name(this, operatorName));
+                    trapFile.Emit(Tuples.dynamic_member_name(this, operatorName));
                     return;
                 }
 
-                cx.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
+                trapFile.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
             }
         }
 
@@ -203,18 +209,18 @@ namespace Semmle.Extraction.CSharp.Entities
             throw new InternalError(node, "Unable to locate a ConditionalAccessExpression");
         }
 
-        public void MakeConditional()
+        public void MakeConditional(TextWriter trapFile)
         {
-            cx.Emit(Tuples.conditional_access(this));
+            trapFile.Emit(Tuples.conditional_access(this));
         }
 
-        public void PopulateArguments(BaseArgumentListSyntax args, int child)
+        public void PopulateArguments(TextWriter trapFile, BaseArgumentListSyntax args, int child)
         {
             foreach (var arg in args.Arguments)
-                PopulateArgument(arg, child++);
+                PopulateArgument(trapFile, arg, child++);
         }
 
-        private void PopulateArgument(ArgumentSyntax arg, int child)
+        private void PopulateArgument(TextWriter trapFile, ArgumentSyntax arg, int child)
         {
             var expr = Create(cx, arg.Expression, this, child);
             int mode;
@@ -235,11 +241,11 @@ namespace Semmle.Extraction.CSharp.Entities
                 default:
                     throw new InternalError(arg, "Unknown argument type");
             }
-            cx.Emit(Tuples.expr_argument(expr, mode));
+            trapFile.Emit(Tuples.expr_argument(expr, mode));
 
             if (arg.NameColon != null)
             {
-                cx.Emit(Tuples.expr_argument_name(expr, arg.NameColon.Name.Identifier.Text));
+                trapFile.Emit(Tuples.expr_argument_name(expr, arg.NameColon.Name.Identifier.Text));
             }
         }
 
@@ -285,11 +291,11 @@ namespace Semmle.Extraction.CSharp.Entities
         /// <see cref="Expression.Create(Context, ExpressionSyntax, IEntity, int, ITypeSymbol)"/> will
         /// still be valid.
         /// </summary>
-        protected abstract void Populate();
+        protected abstract void PopulateExpression(TextWriter trapFile);
 
-        protected Expression TryPopulate()
+        protected new Expression TryPopulate()
         {
-            cx.Try(Syntax, null, Populate);
+            cx.Try(Syntax, null, ()=>PopulateExpression(cx.TrapWriter.Writer));
             return this;
         }
     }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/ArgList.cs

@@ -1,6 +1,7 @@
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using System;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -8,7 +9,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
     {
         ArgList(ExpressionNodeInfo info) : base(info.SetKind(ExprKind.UNKNOWN)) { }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             throw new NotImplementedException();
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/ArrayCreation.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
@@ -18,7 +19,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public abstract InitializerExpressionSyntax  Initializer { get;  }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var child = 0;
             var explicitlySized = false;
@@ -98,7 +99,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new ImplicitArrayCreation(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             if (Syntax.Initializer != null)
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Assignment.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -20,7 +21,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var operatorKind = OperatorKind;
             if (operatorKind.HasValue)
@@ -31,7 +32,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 var opexpr = new Expression(new ExpressionInfo(cx, Type, Location, operatorKind.Value, simpleAssignExpr, 0, false, null));
                 Create(cx, Syntax.Left, opexpr, 0);
                 Create(cx, Syntax.Right, opexpr, 1);
-                opexpr.OperatorCall(Syntax);
+                opexpr.OperatorCall(trapFile, Syntax);
             }
             else
             {
@@ -40,7 +41,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
                 if (Kind == ExprKind.ADD_EVENT || Kind == ExprKind.REMOVE_EVENT)
                 {
-                    OperatorCall(Syntax);
+                    OperatorCall(trapFile, Syntax);
                 }
             }
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Await.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Await(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Binary.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -13,9 +14,9 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Binary(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
-            OperatorCall(Syntax);
+            OperatorCall(trapFile, Syntax);
             CreateDeferred(cx, Syntax.Left, this, 0);
             CreateDeferred(cx, Syntax.Right, this, 1);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Cast.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Cast(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
 
@@ -19,7 +20,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
             else
             {
                 // Type conversion
-                OperatorCall(Syntax);
+                OperatorCall(trapFile, Syntax);
                 TypeMention.Create(cx, Syntax.Type, this, Type);
             }
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Checked.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Checked(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Conditional.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Conditional(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Condition, this, 0);
             Create(cx, Syntax.WhenTrue, this, 1);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Default.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Default(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             TypeAccess.Create(cx, Syntax.Type, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/ElementAccess.cs

@@ -4,6 +4,7 @@ using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -19,7 +20,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
         readonly ExpressionSyntax Qualifier;
         readonly BracketedArgumentListSyntax ArgumentList;
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             if (Kind == ExprKind.POINTER_INDIRECTION)
             {
@@ -27,7 +28,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 var add = new Expression(new ExpressionInfo(cx, qualifierInfo.Type, Location, ExprKind.ADD, this, 0, false, null));
                 qualifierInfo.SetParent(add, 0);
                 CreateFromNode(qualifierInfo);
-                PopulateArguments(ArgumentList, 1);
+                PopulateArguments(trapFile, ArgumentList, 1);
             }
             else
             {
@@ -43,7 +44,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 var indexer = symbolInfo.Symbol as IPropertySymbol;
                 if (indexer != null)
                 {
-                    cx.Emit(Tuples.expr_access(this, Indexer.Create(cx, indexer)));
+                    trapFile.Emit(Tuples.expr_access(this, Indexer.Create(cx, indexer)));
                 }
             }
         }
@@ -86,10 +87,10 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new BindingElementAccess(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
-            base.Populate();
+            base.PopulateExpression(trapFile);
-            MakeConditional();
+            MakeConditional(trapFile);
         }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Initializer.cs

@@ -4,6 +4,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -18,7 +19,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new ArrayInitializer(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var child = 0;
             foreach (var e in Syntax.Expressions)
@@ -44,10 +45,10 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new ImplicitArrayInitializer(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             ArrayInitializer.Create(new ExpressionNodeInfo(cx, Syntax, this, -1));
-            cx.Emit(Tuples.implicitly_typed_array_creation(this));
+            trapFile.Emit(Tuples.implicitly_typed_array_creation(this));
         }
     }
 
@@ -58,7 +59,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new ObjectInitializer(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var child = 0;
 
@@ -98,7 +99,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new CollectionInitializer(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var child = 0;
             foreach (var i in Syntax.Expressions)
@@ -110,7 +111,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 var invocation = new Expression(new ExpressionInfo(cx, voidType, cx.Create(i.GetLocation()), ExprKind.METHOD_INVOCATION, this, child++, false, null));
 
                 if (addMethod != null)
-                    cx.Emit(Tuples.expr_call(invocation, addMethod));
+                    trapFile.Emit(Tuples.expr_call(invocation, addMethod));
                 else
                     cx.ModelError(Syntax, "Unable to find an Add() method for collection initializer");
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/InterpolatedString.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -12,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new InterpolatedString(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var child = 0;
             foreach (var c in Syntax.Contents)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Invocation.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using System.Linq;
 using Microsoft.CodeAnalysis.CSharp;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -18,11 +19,11 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Invocation(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             if (IsNameof(Syntax))
             {
-                PopulateArguments(Syntax.ArgumentList, 0);
+                PopulateArguments(trapFile, Syntax.ArgumentList, 0);
                 return;
             }
 
@@ -44,7 +45,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                     // Conditionally qualified method call; `x?.M()`
                     memberName = memberBinding.Name.Identifier.Text;
                     Create(cx, FindConditionalQualifier(memberBinding), this, child++);
-                    MakeConditional();
+                    MakeConditional(trapFile);
                     break;
                 case SimpleNameSyntax simpleName when (Kind == ExprKind.METHOD_INVOCATION):
                     // Unqualified method call; `M()`
@@ -75,12 +76,12 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
             if (isDynamicCall)
             {
                 if (memberName != null)
-                    cx.Emit(Tuples.dynamic_member_name(this, memberName));
+                    trapFile.Emit(Tuples.dynamic_member_name(this, memberName));
                 else
                     cx.ModelError(Syntax, "Unable to get name for dynamic call.");
             }
 
-            PopulateArguments(Syntax.ArgumentList, child);
+            PopulateArguments(trapFile, Syntax.ArgumentList, child);
 
             if (target == null)
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/IsPattern.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.CSharp;
 using Semmle.Extraction.Kinds;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -148,7 +149,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 Expressions.TypeAccess.Create(cx, optionalType, this, 1);
         }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
             switch (Syntax.Pattern)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Lambda.cs

@@ -5,6 +5,7 @@ using Microsoft.CodeAnalysis;
 using System.Collections.Generic;
 using Semmle.Util;
 using System.Linq;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -12,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
     {
         bool IStatementParentEntity.IsTopLevelParent => false;
 
-        protected override void Populate() { }
+        protected override void PopulateExpression(TextWriter trapFile) { }
 
         void VisitParameter(ParameterSyntax p)
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Literal.cs

@@ -3,6 +3,7 @@ using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis;
 using Semmle.Extraction.CSharp.Populators;
 using Microsoft.CodeAnalysis.CSharp;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -12,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Literal(info).TryPopulate();
 
-        protected override void Populate() { }
+        protected override void PopulateExpression(TextWriter trapFile) { }
 
         static ExprKind GetKind(ExpressionNodeInfo info)
         {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/MakeRef.cs

@@ -1,5 +1,6 @@
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new MakeRef(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/MemberAccess.cs

@@ -31,7 +31,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
         public static Expression Create(ExpressionNodeInfo info, MemberBindingExpressionSyntax node)
         {
             var expr = Create(info, FindConditionalQualifier(node), node.Name);
-            expr.MakeConditional();
+            expr.MakeConditional(info.Context.TrapWriter.Writer);
             return expr;
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/ObjectCreation.cs

@@ -4,6 +4,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
@@ -33,11 +34,11 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new ExplicitObjectCreation(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             if (Syntax.ArgumentList != null)
             {
-                PopulateArguments(Syntax.ArgumentList, 0);
+                PopulateArguments(trapFile, Syntax.ArgumentList, 0);
             }
 
             var target = cx.GetModel(Syntax).GetSymbolInfo(Syntax);
@@ -45,14 +46,14 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
             if (method != null)
             {
-                cx.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
+                trapFile.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
             }
 
             if (IsDynamicObjectCreation(cx, Syntax))
             {
                 var name = GetDynamicName(Syntax.Type);
                 if (name.HasValue)
-                    cx.Emit(Tuples.dynamic_member_name(this, name.Value.Text));
+                    trapFile.Emit(Tuples.dynamic_member_name(this, name.Value.Text));
                 else
                     cx.ModelError(Syntax, "Unable to get name for dynamic object creation.");
             }
@@ -101,14 +102,14 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
         public static Expression Create(ExpressionNodeInfo info) =>
             new ImplicitObjectCreation(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             var target = cx.GetSymbolInfo(Syntax);
             var method = (IMethodSymbol)target.Symbol;
 
             if (method != null)
             {
-                cx.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
+                trapFile.Emit(Tuples.expr_call(this, Method.Create(cx, method)));
             }
             var child = 0;
 
@@ -129,7 +130,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
                 Property.Create(cx, property);
 
                 var access = new Expression(new ExpressionInfo(cx, type, loc, ExprKind.PROPERTY_ACCESS, assignment, 1, false, null));
-                cx.Emit(Tuples.expr_access(access, propEntity));
+                trapFile.Emit(Tuples.expr_access(access, propEntity));
             }
         }
     }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/PointerMemberAccess.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new PointerMemberAccess(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/PostfixUnary.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -17,15 +18,15 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info, ExpressionSyntax operand) => new PostfixUnary(info, info.Kind, operand).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Operand, this, 0);
-            OperatorCall(Syntax);
+            OperatorCall(trapFile, Syntax);
 
             if ((OperatorKind == ExprKind.POST_INCR || OperatorKind == ExprKind.POST_DECR) &&
                 Kind == ExprKind.OPERATOR_INVOCATION)
             {
-                cx.Emit(Tuples.mutator_invocation_mode(this, 2));
+                trapFile.Emit(Tuples.mutator_invocation_mode(this, 2));
             }
         }
     }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/RangeExpression.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
         {
         }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             if (!(Syntax.LeftOperand is null))
                 Expression.Create(cx, Syntax.LeftOperand, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Ref.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Ref(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/RefType.cs

@@ -1,5 +1,6 @@
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new RefType(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/RefValue.cs

@@ -1,5 +1,6 @@
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new RefValue(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
             Create(cx, Syntax.Type, this, 1);   // A type-access

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Sizeof.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new SizeOf(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             TypeAccess.Create(cx, Syntax.Type, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Switch.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -14,7 +15,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public Expression SwitchedExpr { get; private set; }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             SwitchedExpr = Expression.Create(cx, Syntax.GoverningExpression, this, -1);
             int child = 0;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Throw.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Throw(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Tuple.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
@@ -12,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
         {
         }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             int child = 0;
             foreach (var argument in Syntax.Arguments.Select(a => a.Expression))

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/TypeAccess.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -8,7 +9,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
     {
         TypeAccess(ExpressionNodeInfo info) : base(info.SetKind(ExprKind.TYPE_ACCESS)) { }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             switch (Syntax.Kind())
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/TypeOf.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new TypeOf(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             TypeAccess.Create(cx, Syntax.Type, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Unary.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -20,15 +21,15 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Operand, this, 0);
-            OperatorCall(Syntax);
+            OperatorCall(trapFile, Syntax);
 
             if ((OperatorKind == ExprKind.PRE_INCR || OperatorKind == ExprKind.PRE_DECR) &&
                 Kind == ExprKind.OPERATOR_INVOCATION)
             {
-                cx.Emit(Tuples.mutator_invocation_mode(this, 1));
+                trapFile.Emit(Tuples.mutator_invocation_mode(this, 1));
             }
         }
     }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Expressions/Unchecked.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Expressions
 {
@@ -9,7 +10,7 @@ namespace Semmle.Extraction.CSharp.Entities.Expressions
 
         public static Expression Create(ExpressionNodeInfo info) => new Unchecked(info).TryPopulate();
 
-        protected override void Populate()
+        protected override void PopulateExpression(TextWriter trapFile)
         {
             Create(cx, Syntax.Expression, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Field.cs

@@ -25,15 +25,15 @@ namespace Semmle.Extraction.CSharp.Entities
         public override bool NeedsPopulation =>
             (base.NeedsPopulation && !symbol.IsImplicitlyDeclared) || symbol.ContainingType.IsTupleType;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            ExtractMetadataHandle();
+            ExtractMetadataHandle(trapFile);
             ExtractAttributes();
             ContainingType.ExtractGenerics();
-            ExtractNullability(symbol.NullableAnnotation);
+            ExtractNullability(trapFile, symbol.NullableAnnotation);
 
             Field unboundFieldKey = Field.Create(Context, symbol.OriginalDefinition);
-            Context.Emit(Tuples.fields(this, (symbol.IsConst ? 2 : 1), symbol.Name, ContainingType, Type.Type.TypeRef, unboundFieldKey));
+            trapFile.Emit(Tuples.fields(this, (symbol.IsConst ? 2 : 1), symbol.Name, ContainingType, Type.Type.TypeRef, unboundFieldKey));
 
             ExtractModifiers();
 
@@ -46,12 +46,12 @@ namespace Semmle.Extraction.CSharp.Entities
 
                 if (symbol.HasConstantValue)
                 {
-                    Context.Emit(Tuples.constant_value(this, Expression.ValueAsString(symbol.ConstantValue)));
+                    trapFile.Emit(Tuples.constant_value(this, Expression.ValueAsString(symbol.ConstantValue)));
                 }
             }
 
             foreach (var l in Locations)
-                Context.Emit(Tuples.field_location(this, l));
+                trapFile.Emit(Tuples.field_location(this, l));
 
             if (!IsSourceDeclaration || !symbol.FromSource())
                 return;
@@ -86,7 +86,7 @@ namespace Semmle.Extraction.CSharp.Entities
             {
                 // Mark fields that have explicit initializers.
                 var expr = new Expression(new ExpressionInfo(Context, Type, Context.Create(initializer.EqualsValue.Value.FixedLocation()), Kinds.ExprKind.FIELD_ACCESS, this, child++, false, null));
-                Context.Emit(Tuples.expr_access(expr, this));
+                trapFile.Emit(Tuples.expr_access(expr, this));
             }
 
             if (IsSourceDeclaration)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Indexer.cs

@@ -12,14 +12,14 @@ namespace Semmle.Extraction.CSharp.Entities
 
         Indexer OriginalDefinition => IsSourceDeclaration ? this : Create(Context, symbol.OriginalDefinition);
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            ExtractNullability(symbol.NullableAnnotation);
+            ExtractNullability(trapFile, symbol.NullableAnnotation);
 
             var type = Type.Create(Context, symbol.Type);
-            Context.Emit(Tuples.indexers(this, symbol.GetName(useMetadataName: true), ContainingType, type.TypeRef, OriginalDefinition));
+            trapFile.Emit(Tuples.indexers(this, symbol.GetName(useMetadataName: true), ContainingType, type.TypeRef, OriginalDefinition));
             foreach (var l in Locations)
-                Context.Emit(Tuples.indexer_location(this, l));
+                trapFile.Emit(Tuples.indexer_location(this, l));
 
             var getter = symbol.GetMethod;
             var setter = symbol.SetMethod;
@@ -60,7 +60,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
             foreach (var explicitInterface in symbol.ExplicitInterfaceImplementations.Select(impl => Type.Create(Context, impl.ContainingType)))
             {
-                Context.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
+                trapFile.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
 
                 foreach (var syntax in declSyntaxReferences)
                     TypeMention.Create(Context, syntax.ExplicitInterfaceSpecifier.Name, this, explicitInterface);
@@ -71,7 +71,6 @@ namespace Semmle.Extraction.CSharp.Entities
                 TypeMention.Create(Context, syntax.Type, this, type);
         }
 
-
         public static new Indexer Create(Context cx, IPropertySymbol prop) => IndexerFactory.Instance.CreateEntity(cx, prop);
 
         public override void WriteId(TextWriter trapFile)

csharp/extractor/Semmle.Extraction.CSharp/Entities/LocalFunction.cs

@@ -32,9 +32,9 @@ namespace Semmle.Extraction.CSharp.Entities
             public LocalFunction Create(Context cx, IMethodSymbol init) => new LocalFunction(cx, init);
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
 
             // There is a "bug" in Roslyn whereby the IMethodSymbol associated with the local function symbol
             // is always static, so we need to go to the syntax reference of the local function to see whether
@@ -49,8 +49,8 @@ namespace Semmle.Extraction.CSharp.Entities
 
             var originalDefinition = IsSourceDeclaration ? this : Create(Context, symbol.OriginalDefinition);
             var returnType = Type.Create(Context, symbol.ReturnType);
-            Context.Emit(Tuples.local_functions(this, symbol.Name, returnType, originalDefinition));
+            trapFile.Emit(Tuples.local_functions(this, symbol.Name, returnType, originalDefinition));
-            ExtractRefReturn();
+            ExtractRefReturn(trapFile);
         }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/LocalVariable.cs

@@ -27,16 +27,16 @@ namespace Semmle.Extraction.CSharp.Entities
             tw.Write(";localvar");
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             if (symbol is ILocalSymbol local)
             {
-                ExtractNullability(local.NullableAnnotation);
+                ExtractNullability(trapFile, local.NullableAnnotation);
                 if (local.IsRef)
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
             }
 
-            Context.Emit(Tuples.localvars(
+            trapFile.Emit(Tuples.localvars(
                 this,
                 IsRef ? 3 : IsConst ? 2 : 1,
                 symbol.Name,
@@ -44,7 +44,7 @@ namespace Semmle.Extraction.CSharp.Entities
                 Type.Type.TypeRef,
                 Parent));
 
-            Context.Emit(Tuples.localvar_location(this, DeclLocation));
+            trapFile.Emit(Tuples.localvar_location(this, DeclLocation));
 
             DefineConstantValue();
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs

@@ -12,7 +12,7 @@ namespace Semmle.Extraction.CSharp.Entities
         public Method(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
-        protected void ExtractParameters()
+        protected void ExtractParameters(TextWriter trapFile)
         {
             var originalMethod = OriginalDefinition;
             IEnumerable<IParameterSymbol> parameters = symbol.Parameters;
@@ -56,13 +56,13 @@ namespace Semmle.Extraction.CSharp.Entities
         /// <summary>
         /// Extracts constructor initializers.
         /// </summary>
-        protected virtual void ExtractInitializers()
+        protected virtual void ExtractInitializers(TextWriter trapFile)
         {
             // Normal methods don't have initializers,
             // so there's nothing to extract.
         }
 
-        void ExtractMethodBody()
+        void ExtractMethodBody(TextWriter trapFile)
         {
             if (!IsSourceDeclaration)
                 return;
@@ -74,17 +74,17 @@ namespace Semmle.Extraction.CSharp.Entities
                 Context.PopulateLater(
                     () =>
                     {
-                        ExtractInitializers();
+                        ExtractInitializers(trapFile);
                         if (block != null)
                             Statements.Block.Create(Context, block, this, 0);
                         else
                             Expression.Create(Context, expr, this, 0);
 
-                        Context.NumberOfLines(symbol, this);
+                        Context.NumberOfLines(trapFile, symbol, this);
                     });
         }
 
-        public void Overrides()
+        public void Overrides(TextWriter trapFile)
         {
             foreach (var explicitInterface in symbol.ExplicitInterfaceImplementations.
                 Where(sym => sym.MethodKind == MethodKind.Ordinary).
@@ -99,7 +99,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
             if (symbol.OverriddenMethod != null)
             {
-                Context.Emit(Tuples.overrides(this, Method.Create(Context, symbol.OverriddenMethod)));
+                trapFile.Emit(Tuples.overrides(this, Method.Create(Context, symbol.OverriddenMethod)));
             }
         }
 
@@ -330,7 +330,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
         bool IStatementParentEntity.IsTopLevelParent => true;
 
-        protected void ExtractGenerics()
+        protected void ExtractGenerics(TextWriter trapFile)
         {
             var isFullyConstructed = IsBoundGeneric;
 
@@ -340,47 +340,47 @@ namespace Semmle.Extraction.CSharp.Entities
 
                 if (isFullyConstructed)
                 {
-                    Context.Emit(Tuples.is_constructed(this));
+                    trapFile.Emit(Tuples.is_constructed(this));
-                    Context.Emit(Tuples.constructed_generic(this, Method.Create(Context, ConstructedFromSymbol)));
+                    trapFile.Emit(Tuples.constructed_generic(this, Method.Create(Context, ConstructedFromSymbol)));
                     foreach (var tp in symbol.GetAnnotatedTypeArguments())
                     {
-                        Context.Emit(Tuples.type_arguments(Type.Create(Context, tp.Symbol), child, this));
+                        trapFile.Emit(Tuples.type_arguments(Type.Create(Context, tp.Symbol), child, this));
                         var ta = tp.Nullability.GetTypeAnnotation();
                         if (ta != Kinds.TypeAnnotation.None)
-                            Context.Emit(Tuples.type_argument_annotation(this, child, ta));
+                            trapFile.Emit(Tuples.type_argument_annotation(this, child, ta));
                         child++;
                     }
                 }
                 else
                 {
-                    Context.Emit(Tuples.is_generic(this));
+                    trapFile.Emit(Tuples.is_generic(this));
                     foreach (var typeParam in symbol.TypeParameters.Select(tp => TypeParameter.Create(Context, tp)))
                     {
-                        Context.Emit(Tuples.type_parameters(typeParam, child, this));
+                        trapFile.Emit(Tuples.type_parameters(typeParam, child, this));
                         child++;
                     }
                 }
             }
         }
 
-        protected void ExtractRefReturn()
+        protected void ExtractRefReturn(TextWriter trapFile)
         {
             if (symbol.ReturnsByRef)
-                Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
+                trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
             if (symbol.ReturnsByRefReadonly)
-                Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
+                trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
         }
 
-        protected void PopulateMethod()
+        protected void PopulateMethod(TextWriter trapFile)
         {
             // Common population code for all callables
             BindComments();
             ExtractAttributes();
-            ExtractParameters();
+            ExtractParameters(trapFile);
-            ExtractMethodBody();
+            ExtractMethodBody(trapFile);
-            ExtractGenerics();
+            ExtractGenerics(trapFile);
-            ExtractMetadataHandle();
+            ExtractMetadataHandle(trapFile);
-            ExtractNullability(symbol.ReturnNullableAnnotation);
+            ExtractNullability(trapFile, symbol.ReturnNullableAnnotation);
         }
 
         public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.PushesLabel;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Modifier.cs

@@ -41,9 +41,9 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override bool NeedsPopulation => true;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(new Tuple("modifiers", Label, symbol.name));
+            trapFile.Emit(new Tuple("modifiers", Label, symbol.name));
         }
 
         public static string AccessbilityModifier(Accessibility access)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Namespace.cs

@@ -10,14 +10,14 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation => null;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.namespaces(this, symbol.Name));
+            trapFile.Emit(Tuples.namespaces(this, symbol.Name));
 
             if (symbol.ContainingNamespace != null)
             {
                 Namespace parent = Create(Context, symbol.ContainingNamespace);
-                Context.Emit(Tuples.parent_namespace(this, parent));
+                trapFile.Emit(Tuples.parent_namespace(this, parent));
             }
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/NamespaceDeclaration.cs

@@ -3,29 +3,40 @@ using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
     class NamespaceDeclaration : FreshEntity
     {
+        private readonly NamespaceDeclaration Parent;
+        private readonly NamespaceDeclarationSyntax Node;
+
         public NamespaceDeclaration(Context cx, NamespaceDeclarationSyntax node, NamespaceDeclaration parent)
             : base(cx)
         {
-            var ns = Namespace.Create(cx, (INamespaceSymbol)cx.GetModel(node).GetSymbolInfo(node.Name).Symbol);
+            Node = node;
-            cx.Emit(Tuples.namespace_declarations(this, ns));
+            Parent = parent;
-            cx.Emit(Tuples.namespace_declaration_location(this, cx.Create(node.Name.GetLocation())));
+            TryPopulate();
+        }
 
-            var visitor = new Populators.TypeOrNamespaceVisitor(cx, this);
+        protected override void Populate(TextWriter trapFile)
+        {
+            var ns = Namespace.Create(cx, (INamespaceSymbol)cx.GetModel(Node).GetSymbolInfo(Node.Name).Symbol);
+            trapFile.Emit(Tuples.namespace_declarations(this, ns));
+            trapFile.Emit(Tuples.namespace_declaration_location(this, cx.Create(Node.Name.GetLocation())));
 
-            foreach (var member in node.Members.Cast<CSharpSyntaxNode>().Concat(node.Usings))
+            var visitor = new Populators.TypeOrNamespaceVisitor(cx, trapFile, this);
+
+            foreach (var member in Node.Members.Cast<CSharpSyntaxNode>().Concat(Node.Usings))
             {
                 member.Accept(visitor);
             }
 
-            if (parent != null)
+            if (Parent != null)
             {
-                cx.Emit(Tuples.parent_namespace_declaration(this, parent));
+                trapFile.Emit(Tuples.parent_namespace_declaration(this, Parent));
             }
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/OrdinaryMethod.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities
@@ -23,14 +24,14 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation => symbol.GetSymbolLocation();
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ExtractModifiers();
             ContainingType.ExtractGenerics();
 
             var returnType = Type.Create(Context, symbol.ReturnType);
-            Context.Emit(Tuples.methods(this, Name, ContainingType, returnType.TypeRef, OriginalDefinition));
+            trapFile.Emit(Tuples.methods(this, Name, ContainingType, returnType.TypeRef, OriginalDefinition));
 
             if (IsSourceDeclaration)
                 foreach (var declaration in symbol.DeclaringSyntaxReferences.Select(s => s.GetSyntax()).OfType<MethodDeclarationSyntax>())
@@ -42,10 +43,10 @@ namespace Semmle.Extraction.CSharp.Entities
             foreach (var l in Locations)
                 Context.Emit(Tuples.method_location(this, l));
 
-            ExtractGenerics();
+            ExtractGenerics(trapFile);
-            Overrides();
+            Overrides(trapFile);
-            ExtractRefReturn();
+            ExtractRefReturn(trapFile);
-            ExtractCompilerGenerated();
+            ExtractCompilerGenerated(trapFile);
         }
 
         public new static OrdinaryMethod Create(Context cx, IMethodSymbol method) => OrdinaryMethodFactory.Instance.CreateEntity(cx, method);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Parameter.cs

@@ -100,17 +100,17 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             ExtractAttributes();
-            ExtractNullability(symbol.NullableAnnotation);
+            ExtractNullability(trapFile, symbol.NullableAnnotation);
-            ExtractRefKind(symbol.RefKind);
+            ExtractRefKind(trapFile, symbol.RefKind);
 
             if (symbol.Name != Original.symbol.Name)
                 Context.ModelError(symbol, "Inconsistent parameter declaration");
 
             var type = Type.Create(Context, symbol.Type);
-            Context.Emit(Tuples.@params(this, Name, type.TypeRef, Ordinal, ParamKind, Parent, Original));
+            trapFile.Emit(Tuples.@params(this, Name, type.TypeRef, Ordinal, ParamKind, Parent, Original));
 
             foreach (var l in symbol.Locations)
                 Context.Emit(Tuples.param_location(this, Context.Create(l)));
@@ -183,10 +183,10 @@ namespace Semmle.Extraction.CSharp.Entities
         VarargsType(Context cx)
             : base(cx, null) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.types(this, Kinds.TypeKind.ARGLIST, "__arglist"));
+            trapFile.Emit(Tuples.types(this, Kinds.TypeKind.ARGLIST, "__arglist"));
-            Context.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, Context.Compilation.GlobalNamespace)));
+            trapFile.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, Context.Compilation.GlobalNamespace)));
             Modifier.HasModifier(Context, this, "public");
         }
 
@@ -222,12 +222,12 @@ namespace Semmle.Extraction.CSharp.Entities
         VarargsParam(Context cx, Method methodKey)
             : base(cx, null, methodKey, null) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             var typeKey = VarargsType.Create(Context);
             // !! Maybe originaldefinition is wrong
-            Context.Emit(Tuples.@params(this, "", typeKey, Ordinal, Kind.None, Parent, this));
+            trapFile.Emit(Tuples.@params(this, "", typeKey, Ordinal, Kind.None, Parent, this));
-            Context.Emit(Tuples.param_location(this, GeneratedLocation.Create(Context)));
+            trapFile.Emit(Tuples.param_location(this, GeneratedLocation.Create(Context)));
         }
 
         protected override int Ordinal => ((Method)Parent).OriginalDefinition.symbol.Parameters.Length;
@@ -262,11 +262,11 @@ namespace Semmle.Extraction.CSharp.Entities
             ConstructedType = method.symbol.ReceiverType;
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             var typeKey = Type.Create(Context, ConstructedType);
-            Context.Emit(Tuples.@params(this, Original.symbol.Name, typeKey.TypeRef, 0, Kind.This, Parent, Original));
+            trapFile.Emit(Tuples.@params(this, Original.symbol.Name, typeKey.TypeRef, 0, Kind.This, Parent, Original));
-            Context.Emit(Tuples.param_location(this, Original.Location));
+            trapFile.Emit(Tuples.param_location(this, Original.Location));
         }
 
         public override int GetHashCode() => symbol.GetHashCode() + 31 * ConstructedType.GetHashCode();

csharp/extractor/Semmle.Extraction.CSharp/Entities/Property.cs

@@ -22,17 +22,17 @@ namespace Semmle.Extraction.CSharp.Entities
             trapFile.Write(";property");
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            ExtractMetadataHandle();
+            ExtractMetadataHandle(trapFile);
             ExtractAttributes();
             ExtractModifiers();
             BindComments();
-            ExtractNullability(symbol.NullableAnnotation);
+            ExtractNullability(trapFile, symbol.NullableAnnotation);
-            ExtractRefKind(symbol.RefKind);
+            ExtractRefKind(trapFile, symbol.RefKind);
 
             var type = Type.Create(Context, symbol.Type);
-            Context.Emit(Tuples.properties(this, symbol.GetName(), ContainingType, type.TypeRef, Create(Context, symbol.OriginalDefinition)));
+            trapFile.Emit(Tuples.properties(this, symbol.GetName(), ContainingType, type.TypeRef, Create(Context, symbol.OriginalDefinition)));
 
             var getter = symbol.GetMethod;
             var setter = symbol.SetMethod;
@@ -50,7 +50,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
             foreach (var explicitInterface in symbol.ExplicitInterfaceImplementations.Select(impl => Type.Create(Context, impl.ContainingType)))
             {
-                Context.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
+                trapFile.Emit(Tuples.explicitly_implements(this, explicitInterface.TypeRef));
 
                 foreach (var syntax in declSyntaxReferences)
                     TypeMention.Create(Context, syntax.ExplicitInterfaceSpecifier.Name, this, explicitInterface);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statement.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Microsoft.CodeAnalysis.CSharp;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
@@ -40,6 +41,10 @@ namespace Semmle.Extraction.CSharp.Entities
     abstract class Statement<TSyntax> : Statement where TSyntax : CSharpSyntaxNode
     {
         protected readonly TSyntax Stmt;
+        private readonly int Child;
+        private readonly Kinds.StmtKind Kind;
+        private readonly IStatementParentEntity Parent;
+        private readonly Location Location;
 
         protected override CSharpSyntaxNode GetStatementSyntax() => Stmt;
 
@@ -47,33 +52,29 @@ namespace Semmle.Extraction.CSharp.Entities
             : base(cx)
         {
             Stmt = stmt;
+            Parent = parent;
+            Child = child;
+            Location = location;
+            Kind = kind;
             cx.BindComments(this, location.symbol);
-            cx.Emit(Tuples.statements(this, kind));
-            if (parent.IsTopLevelParent)
-                cx.Emit(Tuples.stmt_parent_top_level(this, child, parent));
-            else
-                cx.Emit(Tuples.stmt_parent(this, child, parent));
-            cx.Emit(Tuples.stmt_location(this, location));
         }
 
+        protected override void Populate(TextWriter trapFile)
+        {
+            trapFile.Emit(Tuples.statements(this, Kind));
+            if (Parent.IsTopLevelParent)
+                trapFile.Emit(Tuples.stmt_parent_top_level(this, Child, Parent));
+            else
+                trapFile.Emit(Tuples.stmt_parent(this, Child, Parent));
+            cx.Emit(Tuples.stmt_location(this, Location));
+            PopulateStatement(trapFile);
+        }
+
+        protected abstract void PopulateStatement(TextWriter trapFile);
+
         protected Statement(Context cx, TSyntax stmt, Kinds.StmtKind kind, IStatementParentEntity parent, int child)
             : this(cx, stmt, kind, parent, child, cx.Create(stmt.FixedLocation())) { }
 
-        /// <summary>
-        /// Populates statement-type specific relations in the trap file. The general relations
-        /// <code>statements</code> and <code>stmt_location</code> are populated by the constructor
-        /// (should not fail), so even if statement-type specific population fails (e.g., in
-        /// standalone extraction), the statement created via
-        /// <see cref="Statement.Create(Context, StatementSyntax, Statement, int)"/> will still
-        /// be valid.
-        /// </summary>
-        protected abstract void Populate();
-
-        protected void TryPopulate()
-        {
-            cx.Try(Stmt, null, Populate);
-        }
-
         public override string ToString() => Label.ToString();
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Block.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             var child = 0;
             foreach (var childStmt in Stmt.Statements.Select(c => Statement.Create(cx, c, this, child)))

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Break.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,6 +16,6 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate() { }
+        protected override void PopulateStatement(TextWriter trapFile) { }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Case.cs

@@ -3,6 +3,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -32,7 +33,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
         CaseLabel(Context cx, CaseSwitchLabelSyntax node, Switch parent, int child)
             : base(cx, node, parent, child) { }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             var value = Stmt.Value;
             Expression.Create(cx, value, this, 0);
@@ -52,7 +53,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
         CaseDefault(Context cx, DefaultSwitchLabelSyntax node, Switch parent, int child)
             : base(cx, node, parent, child) { }
 
-        protected override void Populate() { }
+        protected override void PopulateStatement(TextWriter trapFile) { }
 
         public static CaseDefault Create(Context cx, DefaultSwitchLabelSyntax node, Switch parent, int child)
         {
@@ -95,7 +96,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             }
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             switch (Stmt.Pattern)
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Catch.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -12,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
         Catch(Context cx, CatchClauseSyntax node, Try parent, int child)
             : base(cx, node, StmtKind.CATCH, parent, child, cx.Create(node.GetLocation())) { }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             bool isSpecificCatchClause = Stmt.Declaration != null;
             bool hasVariableDeclaration = isSpecificCatchClause && Stmt.Declaration.Identifier.RawKind != 0;
@@ -20,16 +21,16 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             if (hasVariableDeclaration) // A catch clause of the form 'catch(Ex ex) { ... }'
             {
                 var decl = Expressions.VariableDeclaration.Create(cx, Stmt.Declaration, false, this, 0);
-                cx.Emit(Tuples.catch_type(this, decl.Type.Type.TypeRef, true));
+                trapFile.Emit(Tuples.catch_type(this, decl.Type.Type.TypeRef, true));
             }
             else if (isSpecificCatchClause) // A catch clause of the form 'catch(Ex) { ... }'
             {
-                cx.Emit(Tuples.catch_type(this, Type.Create(cx, cx.GetType(Stmt.Declaration.Type)).Type.TypeRef, true));
+                trapFile.Emit(Tuples.catch_type(this, Type.Create(cx, cx.GetType(Stmt.Declaration.Type)).Type.TypeRef, true));
             }
             else // A catch clause of the form 'catch { ... }'
             {
                 var exception = Type.Create(cx, cx.Compilation.GetTypeByMetadataName(SystemExceptionName));
-                cx.Emit(Tuples.catch_type(this, exception, false));
+                trapFile.Emit(Tuples.catch_type(this, exception, false));
             }
 
             if (Stmt.Filter != null)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Checked.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;  // lgtm[cs/similar-file]
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Statement.Create(cx, Stmt.Block, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Continue.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate() { }
+        protected override void PopulateStatement(TextWriter trapFile) { }
     }
 }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Do.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Create(cx, Stmt.Statement, this, 1);
             Expression.Create(cx, Stmt.Condition, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Empty.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,6 +16,6 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate() { }
+        protected override void PopulateStatement(TextWriter trapFile) { }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/ExpressionStatement.cs

@@ -1,4 +1,5 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -14,7 +15,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             if (Stmt.Expression != null)
                 Expression.Create(cx, Stmt.Expression, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Fixed.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Entities.Expressions;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             VariableDeclarations.Populate(cx, Stmt.Declaration, this, -1, childIncrement: -1);
             Create(cx, Stmt.Statement, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/For.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Entities.Expressions;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             int child = -1;
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/ForEach.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -17,7 +18,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter _)
         {
             Expression.Create(cx, Stmt.Expression, this, 1);
 
@@ -44,7 +45,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Expression.Create(cx, Stmt.Variable, this, 0);
             Expression.Create(cx, Stmt.Expression, this, 1);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Goto.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -30,7 +31,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             switch (GetKind(Stmt))
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/If.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Expression.Create(cx, Stmt.Condition, this, 0);
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Labeled.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -22,9 +23,9 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
-            cx.Emit(Tuples.exprorstmt_name(this, Stmt.Identifier.ToString()));
+            trapFile.Emit(Tuples.exprorstmt_name(this, Stmt.Identifier.ToString()));
 
             // For compatilibty with the Mono extractor, make insert the labelled statement into the same block
             // as this one. The parent MUST be a block statement.

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/LocalDeclaration.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Entities.Expressions;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -27,7 +28,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             VariableDeclarations.Populate(cx, Stmt.Declaration, this, 0);
             cx.BindComments(this, Stmt.GetLocation());

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/LocalFunction.cs

@@ -3,6 +3,7 @@ using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis;
 using Semmle.Extraction.Entities;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -40,9 +41,9 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
         /// </summary>
         Entities.LocalFunction Function => Entities.LocalFunction.Create(cx, Symbol);
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
-            cx.Emit(Tuples.local_function_stmts(this, Function));
+            trapFile.Emit(Tuples.local_function_stmts(this, Function));
         }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Lock.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Expression.Create(cx, Stmt.Expression, this, 0);
             Statement.Create(cx, Stmt.Statement, this, 1);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Return.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;  // lgtm[cs/similar-file]
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             if (Stmt.Expression != null)
                 Expression.Create(cx, Stmt.Expression, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Switch.cs

@@ -1,3 +1,4 @@
+using System.IO;
 using System.Linq;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
@@ -27,7 +28,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Expression.Create(cx, Stmt.Expression, this, 0);
             int childIndex = 0;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Throw.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;  // lgtm[cs/similar-file]
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             if (Stmt.Expression != null)
                 Expression.Create(cx, Stmt.Expression, this, 0);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Try.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
 using Microsoft.CodeAnalysis;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             var child = 1;
             foreach (var c in Stmt.Catches)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Unchecked.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;  // lgtm[cs/similar-file]
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Statement.Create(cx, Stmt.Block, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Unsafe.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Create(cx, Stmt.Block, this, 0);
         }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Using.cs

@@ -1,6 +1,7 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Entities.Expressions;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -16,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             if (Stmt.Declaration != null)
                 VariableDeclarations.Populate(cx, Stmt.Declaration, this, -1, childIncrement: -1);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/While.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             Expression.Create(cx, Stmt.Condition, this, 0);
             Create(cx, Stmt.Statement, this, 1);

csharp/extractor/Semmle.Extraction.CSharp/Entities/Statements/Yield.cs

@@ -1,5 +1,6 @@
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Kinds;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities.Statements
 {
@@ -15,7 +16,7 @@ namespace Semmle.Extraction.CSharp.Entities.Statements
             return ret;
         }
 
-        protected override void Populate()
+        protected override void PopulateStatement(TextWriter trapFile)
         {
             if (Stmt.Expression != null)
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/Symbol.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Reflection.Metadata;
 using System.Reflection.Metadata.Ecma335;
@@ -27,33 +28,33 @@ namespace Semmle.Extraction.CSharp.Entities
                 Attribute.ExtractAttributes(Context, symbol, this);
         }
 
-        protected void ExtractNullability(NullableAnnotation annotation)
+        protected void ExtractNullability(TextWriter trapFile, NullableAnnotation annotation)
         {
             var ta = annotation.GetTypeAnnotation();
             if (ta != Kinds.TypeAnnotation.None)
-                Context.Emit(Tuples.type_annotation(this, ta));
+                trapFile.Emit(Tuples.type_annotation(this, ta));
         }
 
-        protected void ExtractRefKind(RefKind kind)
+        protected void ExtractRefKind(TextWriter trapFile, RefKind kind)
         {
             switch (kind)
             {
                 case RefKind.Out:
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Out));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Out));
                     break;
                 case RefKind.Ref:
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
                     break;
                 case RefKind.RefReadOnly:
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
                     break;
             }
         }
 
-        protected void ExtractCompilerGenerated()
+        protected void ExtractCompilerGenerated(TextWriter trapFile)
         {
             if (symbol.IsImplicitlyDeclared)
-                Context.Emit(Tuples.compiler_generated(this));
+                trapFile.Emit(Tuples.compiler_generated(this));
         }
 
         /// <summary>
@@ -124,12 +125,12 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public Extraction.Entities.Location Location => Context.Create(ReportingLocation);
 
-        protected void ExtractMetadataHandle()
+        protected void ExtractMetadataHandle(TextWriter trapFile)
         {
             var handle = MetadataHandle;
 
             if (handle.HasValue)
-                Context.Emit(Tuples.metadata_handle(this, Location, MetadataTokens.GetToken(handle.Value)));
+                trapFile.Emit(Tuples.metadata_handle(this, Location, MetadataTokens.GetToken(handle.Value)));
         }
 
         public Handle? MetadataHandle

csharp/extractor/Semmle.Extraction.CSharp/Entities/TypeMention.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.Entities;
 using Semmle.Util;
+using System.IO;
 using System.Linq;
 
 namespace Semmle.Extraction.CSharp.Entities
@@ -48,19 +49,19 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
-        void Populate()
+        protected override void Populate(TextWriter trapFile)
         {
             switch (Syntax.Kind())
             {
                 case SyntaxKind.ArrayType:
-                    Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                    Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                     Create(cx, GetElementType(Syntax), this, GetElementType(Type));
                     return;
                 case SyntaxKind.NullableType:
                     var nts = (NullableTypeSyntax)Syntax;
                     if (Type is NamedType nt)
                     {
-                        Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                        Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                         Create(cx, nts.ElementType, this, nt.symbol.IsReferenceType ? nt : nt.TypeArguments[0]);
                     }
                     else if(Type is ArrayType array)
@@ -71,25 +72,25 @@ namespace Semmle.Extraction.CSharp.Entities
                 case SyntaxKind.TupleType:
                     var tts = (TupleTypeSyntax)Syntax;
                     var tt = (TupleType)Type;
-                    Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                    Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                     tts.Elements.Zip(tt.TupleElements, (s, t) => Create(cx, s.Type, this, t.Type)).Enumerate();
                     return;
                 case SyntaxKind.PointerType:
                     var pts = (PointerTypeSyntax)Syntax;
                     var pt = (PointerType)Type;
-                    Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                    Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                     Create(cx, pts.ElementType, this, pt.PointedAtType);
                     return;
                 case SyntaxKind.GenericName:
                     var gns = (GenericNameSyntax)Syntax;
-                    Emit(Loc ?? gns.Identifier.GetLocation(), Parent, Type);
+                    Emit(trapFile, Loc ?? gns.Identifier.GetLocation(), Parent, Type);
                     cx.PopulateLater(() => gns.TypeArgumentList.Arguments.Zip(Type.TypeMentions, (s, t) => Create(cx, s, this, t)).Enumerate());
                     return;
                 case SyntaxKind.QualifiedName:
                     if (Type.ContainingType == null)
                     {
                         // namespace qualifier
-                        Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                        Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                     }
                     else
                     {
@@ -100,21 +101,21 @@ namespace Semmle.Extraction.CSharp.Entities
                     }
                     return;
                 default:
-                    Emit(Loc ?? Syntax.GetLocation(), Parent, Type);
+                    Emit(trapFile, Loc ?? Syntax.GetLocation(), Parent, Type);
                     return;
             }
         }
 
-        void Emit(Microsoft.CodeAnalysis.Location loc, IEntity parent, Type type)
+        void Emit(TextWriter trapFile, Microsoft.CodeAnalysis.Location loc, IEntity parent, Type type)
         {
-            cx.Emit(Tuples.type_mention(this, type.TypeRef, parent));
+            trapFile.Emit(Tuples.type_mention(this, type.TypeRef, parent));
-            cx.Emit(Tuples.type_mention_location(this, cx.Create(loc)));
+            trapFile.Emit(Tuples.type_mention_location(this, cx.Create(loc)));
         }
 
         public static TypeMention Create(Context cx, TypeSyntax syntax, IEntity parent, Type type, Microsoft.CodeAnalysis.Location loc = null)
         {
             var ret = new TypeMention(cx, syntax, parent, type, loc);
-            cx.Try(syntax, null, () => ret.Populate());
+            cx.Try(syntax, null, () => ret.Populate(cx.TrapWriter.Writer));
             return ret;
         }
 

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/ArrayType.cs

@@ -23,11 +23,11 @@ namespace Semmle.Extraction.CSharp.Entities
         // be extracted in their defining assembly.
         public override bool NeedsPopulation => true;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.array_element_type(this, Dimension, Rank, element.Type.TypeRef));
+            trapFile.Emit(Tuples.array_element_type(this, Dimension, Rank, element.Type.TypeRef));
-            ExtractType();
+            ExtractType(trapFile);
-            ExtractNullability(symbol.ElementNullableAnnotation);
+            ExtractNullability(trapFile, symbol.ElementNullableAnnotation);
         }
 
         public override void WriteId(TextWriter trapFile)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/DynamicType.cs

@@ -13,13 +13,13 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override Microsoft.CodeAnalysis.Location ReportingLocation => Context.Compilation.ObjectType.Locations.FirstOrDefault();
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.types(this, Kinds.TypeKind.DYNAMIC, "dynamic"));
+            trapFile.Emit(Tuples.types(this, Kinds.TypeKind.DYNAMIC, "dynamic"));
-            Context.Emit(Tuples.type_location(this, Location));
+            trapFile.Emit(Tuples.type_location(this, Location));
 
-            Context.Emit(Tuples.has_modifiers(this, Modifier.Create(Context, "public")));
+            trapFile.Emit(Tuples.has_modifiers(this, Modifier.Create(Context, "public")));
-            Context.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, Context.Compilation.GlobalNamespace)));
+            trapFile.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, Context.Compilation.GlobalNamespace)));
         }
 
         public override void WriteId(TextWriter trapFile)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/NamedType.cs

@@ -21,7 +21,7 @@ namespace Semmle.Extraction.CSharp.Entities
 
         public override bool NeedsPopulation => base.NeedsPopulation || symbol.TypeKind == TypeKind.Error;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             if (symbol.TypeKind == TypeKind.Error)
             {
@@ -29,54 +29,54 @@ namespace Semmle.Extraction.CSharp.Entities
                 return;
             }
 
-            Context.Emit(Tuples.typeref_type((NamedTypeRef)TypeRef, this));
+            trapFile.Emit(Tuples.typeref_type((NamedTypeRef)TypeRef, this));
 
             if (symbol.IsGenericType)
             {
                 if (symbol.IsBoundNullable())
                 {
                     // An instance of Nullable<T>
-                    Context.Emit(Tuples.nullable_underlying_type(this, Create(Context, symbol.TypeArguments[0]).TypeRef));
+                    trapFile.Emit(Tuples.nullable_underlying_type(this, Create(Context, symbol.TypeArguments[0]).TypeRef));
                 }
                 else if (symbol.IsReallyUnbound())
                 {
-                    Context.Emit(Tuples.is_generic(this));
+                    trapFile.Emit(Tuples.is_generic(this));
 
                     for (int i = 0; i < symbol.TypeParameters.Length; ++i)
                     {
                         TypeParameter.Create(Context, symbol.TypeParameters[i]);
                         var param = symbol.TypeParameters[i];
                         var typeParameter = TypeParameter.Create(Context, param);
-                        Context.Emit(Tuples.type_parameters(typeParameter, i, this));
+                        trapFile.Emit(Tuples.type_parameters(typeParameter, i, this));
                     }
                 }
                 else
                 {
-                    Context.Emit(Tuples.is_constructed(this));
+                    trapFile.Emit(Tuples.is_constructed(this));
-                    Context.Emit(Tuples.constructed_generic(this, Type.Create(Context, symbol.ConstructedFrom).TypeRef));
+                    trapFile.Emit(Tuples.constructed_generic(this, Type.Create(Context, symbol.ConstructedFrom).TypeRef));
 
                     for (int i = 0; i < symbol.TypeArguments.Length; ++i)
                     {
                         var ta = symbol.TypeArgumentsNullableAnnotations[i].GetTypeAnnotation();
                         if (ta != Kinds.TypeAnnotation.None)
-                            Context.Emit(Tuples.type_argument_annotation(this, i, ta));
+                            trapFile.Emit(Tuples.type_argument_annotation(this, i, ta));
-                        Context.Emit(Tuples.type_arguments(TypeArguments[i].TypeRef, i, this));
+                        trapFile.Emit(Tuples.type_arguments(TypeArguments[i].TypeRef, i, this));
                     }
                 }
             }
 
-            ExtractType();
+            ExtractType(trapFile);
 
             if (symbol.EnumUnderlyingType != null)
             {
-                Context.Emit(Tuples.enum_underlying_type(this, Type.Create(Context, symbol.EnumUnderlyingType).TypeRef));
+                trapFile.Emit(Tuples.enum_underlying_type(this, Type.Create(Context, symbol.EnumUnderlyingType).TypeRef));
             }
 
             // Class location
             if (!symbol.IsGenericType || symbol.IsReallyUnbound())
             {
                 foreach (var l in Locations)
-                    Context.Emit(Tuples.type_location(this, l));
+                    trapFile.Emit(Tuples.type_location(this, l));
             }
         }
 
@@ -183,9 +183,9 @@ namespace Semmle.Extraction.CSharp.Entities
             trapFile.Write(";typeRef");
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.typerefs(this, symbol.Name));
+            trapFile.Emit(Tuples.typerefs(this, symbol.Name));
         }
     };
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/NullType.cs

@@ -8,9 +8,9 @@ namespace Semmle.Extraction.CSharp.Entities
         NullType(Context cx)
             : base(cx, null) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.types(this, Kinds.TypeKind.NULL, "null"));
+            trapFile.Emit(Tuples.types(this, Kinds.TypeKind.NULL, "null"));
         }
 
         public override void WriteId(TextWriter trapFile)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/PointerType.cs

@@ -21,10 +21,10 @@ namespace Semmle.Extraction.CSharp.Entities
         // be extracted in their defining assembly.
         public override bool NeedsPopulation => true;
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            Context.Emit(Tuples.pointer_referent_type(this, PointedAtType.TypeRef));
+            trapFile.Emit(Tuples.pointer_referent_type(this, PointedAtType.TypeRef));
-            ExtractType();
+            ExtractType(trapFile);
         }
 
         public Type PointedAtType { get; private set; }

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TupleType.cs

@@ -36,23 +36,23 @@ namespace Semmle.Extraction.CSharp.Entities
             trapFile.Write(";tuple");
         }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            ExtractType();
+            ExtractType(trapFile);
             ExtractGenerics();
 
             var underlyingType = NamedType.Create(Context, symbol.TupleUnderlyingType);
-            Context.Emit(Tuples.tuple_underlying_type(this, underlyingType));
+            trapFile.Emit(Tuples.tuple_underlying_type(this, underlyingType));
 
             int index = 0;
             foreach (var element in TupleElements)
-                Context.Emit(Tuples.tuple_element(this, index++, element));
+                trapFile.Emit(Tuples.tuple_element(this, index++, element));
 
             // Note: symbol.Locations seems to be very inconsistent
             // about what locations are available for a tuple type.
             // Sometimes it's the source code, and sometimes it's empty.
             foreach (var l in symbol.Locations)
-                Context.Emit(Tuples.type_location(this, Context.Create(l)));
+                trapFile.Emit(Tuples.type_location(this, Context.Create(l)));
         }
 
         readonly Lazy<Field[]> tupleElementsLazy;

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/Type.cs

@@ -78,35 +78,35 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
-        protected void ExtractType()
+        protected void ExtractType(TextWriter trapFile)
         {
-            ExtractMetadataHandle();
+            ExtractMetadataHandle(trapFile);
             ExtractAttributes();
 
             var tb = new StringWriter();
             symbol.BuildDisplayName(Context, tb);
-            Context.Emit(Tuples.types(this, GetClassType(Context, symbol), tb.ToString()));
+            trapFile.Emit(Tuples.types(this, GetClassType(Context, symbol), tb.ToString()));
 
             // Visit base types
             var baseTypes = new List<Type>();
             if (symbol.BaseType != null)
             {
                 Type baseKey = Create(Context, symbol.BaseType);
-                Context.Emit(Tuples.extend(this, baseKey.TypeRef));
+                trapFile.Emit(Tuples.extend(this, baseKey.TypeRef));
                 if (symbol.TypeKind != TypeKind.Struct)
                     baseTypes.Add(baseKey);
             }
 
-            if (base.symbol.TypeKind == TypeKind.Interface)
+            if (symbol.TypeKind == TypeKind.Interface)
             {
-                Context.Emit(Tuples.extend(this, Create(Context, Context.Compilation.ObjectType)));
+                trapFile.Emit(Tuples.extend(this, Create(Context, Context.Compilation.ObjectType)));
             }
 
             if (!(base.symbol is IArrayTypeSymbol))
             {
                 foreach (var t in base.symbol.Interfaces.Select(i=>Create(Context, i)))
                 {
-                    Context.Emit(Tuples.implement(this, t.TypeRef));
+                    trapFile.Emit(Tuples.implement(this, t.TypeRef));
                     baseTypes.Add(t);
                 }
             }
@@ -115,11 +115,11 @@ namespace Semmle.Extraction.CSharp.Entities
             if (containingType != null && symbol.Kind != SymbolKind.TypeParameter)
             {
                 Type originalDefinition = symbol.TypeKind == TypeKind.Error ? this : Create(Context, symbol.OriginalDefinition);
-                Context.Emit(Tuples.nested_types(this, containingType, originalDefinition));
+                trapFile.Emit(Tuples.nested_types(this, containingType, originalDefinition));
             }
             else if (symbol.ContainingNamespace != null)
             {
-                Context.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, symbol.ContainingNamespace)));
+                trapFile.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, symbol.ContainingNamespace)));
             }
 
             if (symbol is IArrayTypeSymbol)
@@ -128,7 +128,7 @@ namespace Semmle.Extraction.CSharp.Entities
                 ITypeSymbol elementType = ((IArrayTypeSymbol)symbol).ElementType;
                 INamespaceSymbol ns = elementType.TypeKind == TypeKind.TypeParameter ? Context.Compilation.GlobalNamespace : elementType.ContainingNamespace;
                 if (ns != null)
-                    Context.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, ns)));
+                    trapFile.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, ns)));
             }
 
             if (symbol is IPointerTypeSymbol)
@@ -137,7 +137,7 @@ namespace Semmle.Extraction.CSharp.Entities
                 INamespaceSymbol ns = elementType.TypeKind == TypeKind.TypeParameter ? Context.Compilation.GlobalNamespace : elementType.ContainingNamespace;
 
                 if (ns != null)
-                    Context.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, ns)));
+                    trapFile.Emit(Tuples.parent_namespace(this, Namespace.Create(Context, ns)));
             }
 
             if (symbol.BaseType != null && symbol.BaseType.SpecialType == SpecialType.System_MulticastDelegate)
@@ -157,11 +157,11 @@ namespace Semmle.Extraction.CSharp.Entities
                 }
 
                 var returnKey = Create(Context, invokeMethod.ReturnType);
-                Context.Emit(Tuples.delegate_return_type(this, returnKey.TypeRef));
+                trapFile.Emit(Tuples.delegate_return_type(this, returnKey.TypeRef));
                 if (invokeMethod.ReturnsByRef)
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.Ref));
                 if (invokeMethod.ReturnsByRefReadonly)
-                    Context.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
+                    trapFile.Emit(Tuples.type_annotation(this, Kinds.TypeAnnotation.ReadonlyRef));
             }
 
             Modifier.ExtractModifiers(Context, this, symbol);
@@ -251,11 +251,11 @@ namespace Semmle.Extraction.CSharp.Entities
             }
         }
 
-        public void ExtractRecursive(IEntity parent)
+        public void ExtractRecursive(TextWriter trapFile, IEntity parent)
         {
             if (symbol.ContainingSymbol.Kind == SymbolKind.Namespace && !symbol.ContainingNamespace.IsGlobalNamespace)
             {
-                Context.Emit(Tuples.parent_namespace_declaration(this, (NamespaceDeclaration)parent));
+                trapFile.Emit(Tuples.parent_namespace_declaration(this, (NamespaceDeclaration)parent));
             }
 
             ExtractRecursive();

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TypeParameter.cs

@@ -21,49 +21,49 @@ namespace Semmle.Extraction.CSharp.Entities
 
         static readonly string valueTypeName = typeof(System.ValueType).ToString();
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
             var constraints = new TypeParameterConstraints(Context);
-            Context.Emit(Tuples.type_parameter_constraints(constraints, this));
+            trapFile.Emit(Tuples.type_parameter_constraints(constraints, this));
 
             if (symbol.HasReferenceTypeConstraint)
-                Context.Emit(Tuples.general_type_parameter_constraints(constraints, 1));
+                trapFile.Emit(Tuples.general_type_parameter_constraints(constraints, 1));
 
             if (symbol.HasValueTypeConstraint)
-                Context.Emit(Tuples.general_type_parameter_constraints(constraints, 2));
+                trapFile.Emit(Tuples.general_type_parameter_constraints(constraints, 2));
 
             if (symbol.HasConstructorConstraint)
-                Context.Emit(Tuples.general_type_parameter_constraints(constraints, 3));
+                trapFile.Emit(Tuples.general_type_parameter_constraints(constraints, 3));
 
             if(symbol.HasUnmanagedTypeConstraint)
-                Context.Emit(Tuples.general_type_parameter_constraints(constraints, 4));
+                trapFile.Emit(Tuples.general_type_parameter_constraints(constraints, 4));
 
             ITypeSymbol baseType = symbol.HasValueTypeConstraint ?
                     Context.Compilation.GetTypeByMetadataName(valueTypeName) :
                     Context.Compilation.ObjectType;
 
             if(symbol.ReferenceTypeConstraintNullableAnnotation == NullableAnnotation.Annotated)
-                Context.Emit(Tuples.general_type_parameter_constraints(constraints, 5));
+                trapFile.Emit(Tuples.general_type_parameter_constraints(constraints, 5));
 
             foreach (var abase in symbol.GetAnnotatedTypeConstraints())
             {
                 if (abase.Symbol.TypeKind != TypeKind.Interface)
                     baseType = abase.Symbol;
                 var t = Create(Context, abase.Symbol);
-                Context.Emit(Tuples.specific_type_parameter_constraints(constraints, t.TypeRef));
+                trapFile.Emit(Tuples.specific_type_parameter_constraints(constraints, t.TypeRef));
                 if (abase.Nullability.GetTypeAnnotation() != Kinds.TypeAnnotation.None)
-                    Context.Emit(Tuples.specific_type_parameter_annotation(constraints, t.TypeRef, abase.Nullability.GetTypeAnnotation()));
+                    trapFile.Emit(Tuples.specific_type_parameter_annotation(constraints, t.TypeRef, abase.Nullability.GetTypeAnnotation()));
             }
 
-            Context.Emit(Tuples.types(this, Semmle.Extraction.Kinds.TypeKind.TYPE_PARAMETER, symbol.Name));
+            trapFile.Emit(Tuples.types(this, Semmle.Extraction.Kinds.TypeKind.TYPE_PARAMETER, symbol.Name));
-            Context.Emit(Tuples.extend(this, Create(Context, baseType).TypeRef));
+            trapFile.Emit(Tuples.extend(this, Create(Context, baseType).TypeRef));
 
             Namespace parentNs = Namespace.Create(Context, symbol.TypeParameterKind == TypeParameterKind.Method ? Context.Compilation.GlobalNamespace : symbol.ContainingNamespace);
-            Context.Emit(Tuples.parent_namespace(this, parentNs));
+            trapFile.Emit(Tuples.parent_namespace(this, parentNs));
 
             foreach (var l in symbol.Locations)
             {
-                Context.Emit(Tuples.type_location(this, Context.Create(l)));
+                trapFile.Emit(Tuples.type_location(this, Context.Create(l)));
             }
 
             if (this.IsSourceDeclaration)

csharp/extractor/Semmle.Extraction.CSharp/Entities/Types/TypeParameterConstraints.cs

@@ -1,3 +1,5 @@
+using System.IO;
+
 namespace Semmle.Extraction.CSharp.Entities
 {
     class TypeParameterConstraints : FreshEntity
@@ -6,5 +8,9 @@ namespace Semmle.Extraction.CSharp.Entities
             : base(cx) { }
 
         public override TrapStackBehaviour TrapStackBehaviour => TrapStackBehaviour.NoLabel;
+
+        protected override void Populate(TextWriter trapFile)
+        {
+        }
     }
 }

csharp/extractor/Semmle.Extraction.CSharp/Entities/UserOperator.cs

@@ -10,13 +10,13 @@ namespace Semmle.Extraction.CSharp.Entities
         protected UserOperator(Context cx, IMethodSymbol init)
             : base(cx, init) { }
 
-        public override void Populate()
+        public override void Populate(TextWriter trapFile)
         {
-            PopulateMethod();
+            PopulateMethod(trapFile);
             ExtractModifiers();
 
             var returnType = Type.Create(Context, symbol.ReturnType);
-            Context.Emit(Tuples.operators(this,
+            trapFile.Emit(Tuples.operators(this,
                 symbol.Name,
                 OperatorSymbol(Context, symbol.Name),
                 ContainingType,
@@ -24,7 +24,7 @@ namespace Semmle.Extraction.CSharp.Entities
                 (UserOperator)OriginalDefinition));
 
             foreach (var l in Locations)
-                Context.Emit(Tuples.operator_location(this, l));
+                trapFile.Emit(Tuples.operator_location(this, l));
 
             if (IsSourceDeclaration)
             {

csharp/extractor/Semmle.Extraction.CSharp/Entities/UsingDirective.cs

@@ -4,52 +4,61 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Populators;
 using Semmle.Extraction.Entities;
 using System.Collections.Generic;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Entities
 {
     class UsingDirective : FreshEntity
     {
-        readonly UsingDirectiveSyntax node;
+        readonly UsingDirectiveSyntax Node;
+        readonly NamespaceDeclaration Parent;
 
         public UsingDirective(Context cx, UsingDirectiveSyntax usingDirective, NamespaceDeclaration parent)
             : base(cx)
         {
-            node = usingDirective;
+            var trapFile = cx.TrapWriter.Writer;
-            var info = cx.GetModel(node).GetSymbolInfo(usingDirective.Name);
+            Node = usingDirective;
+            Parent = parent;
+            TryPopulate();
+        }
 
-            if (usingDirective.StaticKeyword.Kind() == SyntaxKind.None)
+        protected override void Populate(TextWriter trapFile)
+        {
+            var info = cx.GetModel(Node).GetSymbolInfo(Node.Name);
+
+            if (Node.StaticKeyword.Kind() == SyntaxKind.None)
             {
                 // A normal using
                 var namespaceSymbol = info.Symbol as INamespaceSymbol;
 
                 if (namespaceSymbol == null)
                 {
-                    cx.Extractor.MissingNamespace(usingDirective.Name.ToFullString());
+                    cx.Extractor.MissingNamespace(Node.Name.ToFullString());
-                    cx.ModelError(usingDirective, "Namespace not found");
+                    cx.ModelError(Node, "Namespace not found");
                     return;
                 }
                 else
                 {
                     var ns = Namespace.Create(cx, namespaceSymbol);
-                    cx.Emit(Tuples.using_namespace_directives(this, ns));
+                    trapFile.Emit(Tuples.using_namespace_directives(this, ns));
-                    cx.Emit(Tuples.using_directive_location(this, cx.Create(ReportingLocation)));
+                    trapFile.Emit(Tuples.using_directive_location(this, cx.Create(ReportingLocation)));
                 }
             }
             else
             {
                 // A "using static"
                 Type m = Type.Create(cx, (ITypeSymbol)info.Symbol);
-                cx.Emit(Tuples.using_static_directives(this, m.TypeRef));
+                trapFile.Emit(Tuples.using_static_directives(this, m.TypeRef));
-                cx.Emit(Tuples.using_directive_location(this, cx.Create(ReportingLocation)));
+                trapFile.Emit(Tuples.using_directive_location(this, cx.Create(ReportingLocation)));
             }
 
-            if (parent != null)
+            if (Parent != null)
             {
-                cx.Emit(Tuples.parent_namespace_declaration(this, parent));
+                trapFile.Emit(Tuples.parent_namespace_declaration(this, Parent));
             }
         }
 
-        public sealed override Microsoft.CodeAnalysis.Location ReportingLocation => node.GetLocation();
+        public sealed override Microsoft.CodeAnalysis.Location ReportingLocation => Node.GetLocation();
 
         public IEnumerable<Tuple> GetTuples()
         {

csharp/extractor/Semmle.Extraction.CSharp/Populators/CompilationUnit.cs

@@ -4,6 +4,7 @@ using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Extraction.CSharp.Entities;
 using Semmle.Extraction.Entities;
 using Semmle.Util.Logging;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Populators
 {
@@ -11,11 +12,13 @@ namespace Semmle.Extraction.CSharp.Populators
     {
         protected readonly Context cx;
         protected readonly IEntity parent;
+        protected readonly TextWriter trapFile;
 
-        public TypeContainerVisitor(Context cx, IEntity parent)
+        public TypeContainerVisitor(Context cx, TextWriter trapFile, IEntity parent)
         {
             this.cx = cx;
             this.parent = parent;
+            this.trapFile = trapFile;
         }
 
         public override void DefaultVisit(SyntaxNode node)
@@ -25,27 +28,27 @@ namespace Semmle.Extraction.CSharp.Populators
 
         public override void VisitDelegateDeclaration(DelegateDeclarationSyntax node)
         {
-            Entities.NamedType.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(parent);
+            Entities.NamedType.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
         }
 
         public override void VisitClassDeclaration(ClassDeclarationSyntax classDecl)
         {
-            Entities.Type.Create(cx, cx.GetModel(classDecl).GetDeclaredSymbol(classDecl)).ExtractRecursive(parent);
+            Entities.Type.Create(cx, cx.GetModel(classDecl).GetDeclaredSymbol(classDecl)).ExtractRecursive(trapFile, parent);
         }
 
         public override void VisitStructDeclaration(StructDeclarationSyntax node)
         {
-            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(parent);
+            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
         }
 
         public override void VisitEnumDeclaration(EnumDeclarationSyntax node)
         {
-            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(parent);
+            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
         }
 
         public override void VisitInterfaceDeclaration(InterfaceDeclarationSyntax node)
         {
-            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(parent);
+            Entities.Type.Create(cx, cx.GetModel(node).GetDeclaredSymbol(node)).ExtractRecursive(trapFile, parent);
         }
 
         public override void VisitAttributeList(AttributeListSyntax node)
@@ -63,8 +66,8 @@ namespace Semmle.Extraction.CSharp.Populators
 
     class TypeOrNamespaceVisitor : TypeContainerVisitor
     {
-        public TypeOrNamespaceVisitor(Context cx, IEntity parent)
+        public TypeOrNamespaceVisitor(Context cx, TextWriter trapFile, IEntity parent)
-            : base(cx, parent) { }
+            : base(cx, trapFile, parent) { }
 
         public override void VisitUsingDirective(UsingDirectiveSyntax usingDirective)
         {
@@ -82,7 +85,7 @@ namespace Semmle.Extraction.CSharp.Populators
     class CompilationUnitVisitor : TypeOrNamespaceVisitor
     {
         public CompilationUnitVisitor(Context cx)
-            : base(cx, null) { }
+            : base(cx, cx.TrapWriter.Writer, null) { }
 
         public override void VisitExternAliasDirective(ExternAliasDirectiveSyntax node)
         {
@@ -120,7 +123,7 @@ namespace Semmle.Extraction.CSharp.Populators
         public static void Extract(Context cx, SyntaxNode unit)
         {
             // Ensure that the file itself is populated in case the source file is totally empty
-            File.Create(cx, unit.SyntaxTree.FilePath);
+            Semmle.Extraction.Entities.File.Create(cx, unit.SyntaxTree.FilePath);
 
             ((CSharpSyntaxNode)unit).Accept(new CompilationUnitVisitor(cx));
         }

csharp/extractor/Semmle.Extraction.CSharp/Populators/Methods.cs

@@ -2,6 +2,7 @@ using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Semmle.Util;
+using System.IO;
 
 namespace Semmle.Extraction.CSharp.Populators
 {
@@ -47,18 +48,18 @@ namespace Semmle.Extraction.CSharp.Populators
             }
         }
 
-        public static void NumberOfLines(this Context cx, ISymbol symbol, IEntity callable)
+        public static void NumberOfLines(this Context cx, TextWriter trapFile, ISymbol symbol, IEntity callable)
         {
             foreach (var decl in symbol.DeclaringSyntaxReferences)
             {
-                cx.NumberOfLines((CSharpSyntaxNode)decl.GetSyntax(), callable);
+                cx.NumberOfLines(trapFile, (CSharpSyntaxNode)decl.GetSyntax(), callable);
             }
         }
 
-        public static void NumberOfLines(this Context cx, CSharpSyntaxNode node, IEntity callable)
+        public static void NumberOfLines(this Context cx, TextWriter trapFile, CSharpSyntaxNode node, IEntity callable)
         {
             var lineCounts = node.Accept(new AstLineCounter());
-            cx.Emit(Tuples.numlines(callable, lineCounts));
+            trapFile.Emit(Tuples.numlines(callable, lineCounts));
         }
     }
 }

csharp/extractor/Semmle.Extraction/Context.cs

@@ -387,8 +387,8 @@ namespace Semmle.Extraction
             }
 
             var a = duplicationGuard ?
-                (Action)(() => WithDuplicationGuard(new Key(entity, this.Create(entity.ReportingLocation)), entity.Populate)) :
+                (Action)(() => WithDuplicationGuard(new Key(entity, this.Create(entity.ReportingLocation)), () => entity.Populate(TrapWriter.Writer))) :
-                (Action)(() => this.Try(null, optionalSymbol, entity.Populate));
+                (Action)(() => this.Try(null, optionalSymbol, () => entity.Populate(TrapWriter.Writer)));
 
             if (deferred)
                 populateQueue.Enqueue(a);