Merge pull request #2557 from calumgrant/cs/extractor-label-catch

hvitved · web-flow · commit 665d38647dd5 · 2019-12-20T13:09:21.000+01:00
C# extractor: Catch exceptions when generating trap
diff --git a/csharp/extractor/Semmle.Extraction.CIL/Factories.cs b/csharp/extractor/Semmle.Extraction.CIL/Factories.cs
@@ -28,7 +28,7 @@ public T Populate<T>(T e) where T : IExtractedEntity
             else
             {
                 e.Label = cx.GetNewLabel();
-                cx.DefineLabel(e, cx.TrapWriter.Writer);
+                cx.DefineLabel(e, cx.TrapWriter.Writer, cx.Extractor);
                 ids.Add(e, e.Label);
                 cx.PopulateLater(() =>
                 {
@@ -76,7 +76,7 @@ public PrimitiveType Create(PrimitiveTypeCode code)
             {
                 e = new PrimitiveType(this, code);
                 e.Label = cx.GetNewLabel();
-                cx.DefineLabel(e, cx.TrapWriter.Writer);
+                cx.DefineLabel(e, cx.TrapWriter.Writer, cx.Extractor);
                 primitiveTypes[(int)code] = e;
             }
 
diff --git a/csharp/extractor/Semmle.Extraction/Context.cs b/csharp/extractor/Semmle.Extraction/Context.cs
@@ -57,19 +57,19 @@ public Entity CreateEntity<Type, Entity>(ICachedEntityFactory<Type, Entity> fact
         // A recursion guard against writing to the trap file whilst writing an id to the trap file.
         bool WritingLabel = false;
 
-        public void DefineLabel(IEntity entity, TextWriter trapFile)
+        public void DefineLabel(IEntity entity, TextWriter trapFile, IExtractor extractor)
         {
             if (WritingLabel)
             {
                 // Don't define a label whilst writing a label.
-                PopulateLater(() => DefineLabel(entity, trapFile));
+                PopulateLater(() => DefineLabel(entity, trapFile, extractor));
             }
             else
             {
                 try
                 {
                     WritingLabel = true;
-                    entity.DefineLabel(trapFile);
+                    entity.DefineLabel(trapFile, extractor);
                 }
                 finally
                 {
@@ -102,7 +102,7 @@ public Entity CreateEntity2<Type, Entity>(ICachedEntityFactory<Type, Entity> fac
                     entity.Label = label;
                     entityLabelCache[entity] = label;
 
-                    DefineLabel(entity, TrapWriter.Writer);
+                    DefineLabel(entity, TrapWriter.Writer, Extractor);
 
                     if (entity.NeedsPopulation)
                         Populate(init as ISymbol, entity);
@@ -148,7 +148,7 @@ private Entity CreateNonNullEntity<Type, Entity>(ICachedEntityFactory<Type, Enti
 
                 objectEntityCache[init] = entity;
 
-                DefineLabel(entity, TrapWriter.Writer);
+                DefineLabel(entity, TrapWriter.Writer, Extractor);
                 if (entity.NeedsPopulation)
                     Populate(init as ISymbol, entity);
 
diff --git a/csharp/extractor/Semmle.Extraction/Entity.cs b/csharp/extractor/Semmle.Extraction/Entity.cs
@@ -1,4 +1,5 @@
 using Microsoft.CodeAnalysis;
+using System;
 using System.IO;
 
 namespace Semmle.Extraction
@@ -141,11 +142,19 @@ public static Entity CreateEntity<Type, Entity>(this ICachedEntityFactory<Type,
         public static Entity CreateEntity2<Type, Entity>(this ICachedEntityFactory<Type, Entity> factory, Context cx, Type init)
             where Entity : ICachedEntity => cx.CreateEntity2(factory, init);
 
-        public static void DefineLabel(this IEntity entity, TextWriter trapFile)
+        public static void DefineLabel(this IEntity entity, TextWriter trapFile, IExtractor extractor)
         {
             trapFile.WriteLabel(entity);
             trapFile.Write("=");
-            entity.WriteQuotedId(trapFile);
+            try
+            {
+                entity.WriteQuotedId(trapFile);
+            }
+            catch(Exception ex)  // lgtm[cs/catch-of-all-exceptions]
+            {
+                trapFile.WriteLine("\"");
+                extractor.Message(new Message("Unhandled exception generating id", entity.ToString(), null, ex.StackTrace.ToString()));
+            }
             trapFile.WriteLine();
         }
 
diff --git a/csharp/extractor/Semmle.Extraction/TrapExtensions.cs b/csharp/extractor/Semmle.Extraction/TrapExtensions.cs
@@ -19,6 +19,12 @@ public static void WriteLabel(this TextWriter trapFile, IEntity entity)
 
         public static void WriteSubId(this TextWriter trapFile, IEntity entity)
         {
+            if (entity is null)
+            {
+                trapFile.Write("<null>");
+                return;
+            }
+
             trapFile.Write('{');
             trapFile.WriteLabel(entity);
             trapFile.Write('}');

Original file line number	Diff line number	Diff line change
`@@ -28,7 +28,7 @@ public T Populate<T>(T e) where T : IExtractedEntity`
`28`	`28`	`else`
`29`	`29`	`{`
`30`	`30`	`e.Label = cx.GetNewLabel();`
`31`		`- cx.DefineLabel(e, cx.TrapWriter.Writer);`
	`31`	`+ cx.DefineLabel(e, cx.TrapWriter.Writer, cx.Extractor);`
`32`	`32`	`ids.Add(e, e.Label);`
`33`	`33`	`cx.PopulateLater(() =>`
`34`	`34`	`{`
`@@ -76,7 +76,7 @@ public PrimitiveType Create(PrimitiveTypeCode code)`
`76`	`76`	`{`
`77`	`77`	`e = new PrimitiveType(this, code);`
`78`	`78`	`e.Label = cx.GetNewLabel();`
`79`		`- cx.DefineLabel(e, cx.TrapWriter.Writer);`
	`79`	`+ cx.DefineLabel(e, cx.TrapWriter.Writer, cx.Extractor);`
`80`	`80`	`primitiveTypes[(int)code] = e;`
`81`	`81`	`}`
`82`	`82`
Original file line number	Diff line number	Diff line change
`@@ -57,19 +57,19 @@ public Entity CreateEntity<Type, Entity>(ICachedEntityFactory<Type, Entity> fact`
`57`	`57`	`// A recursion guard against writing to the trap file whilst writing an id to the trap file.`
`58`	`58`	`bool WritingLabel = false;`
`59`	`59`
`60`		`- public void DefineLabel(IEntity entity, TextWriter trapFile)`
	`60`	`+ public void DefineLabel(IEntity entity, TextWriter trapFile, IExtractor extractor)`
`61`	`61`	`{`
`62`	`62`	`if (WritingLabel)`
`63`	`63`	`{`
`64`	`64`	`// Don't define a label whilst writing a label.`
`65`		`- PopulateLater(() => DefineLabel(entity, trapFile));`
	`65`	`+ PopulateLater(() => DefineLabel(entity, trapFile, extractor));`
`66`	`66`	`}`
`67`	`67`	`else`
`68`	`68`	`{`
`69`	`69`	`try`
`70`	`70`	`{`
`71`	`71`	`WritingLabel = true;`
`72`		`- entity.DefineLabel(trapFile);`
	`72`	`+ entity.DefineLabel(trapFile, extractor);`
`73`	`73`	`}`
`74`	`74`	`finally`
`75`	`75`	`{`
`@@ -102,7 +102,7 @@ public Entity CreateEntity2<Type, Entity>(ICachedEntityFactory<Type, Entity> fac`
`102`	`102`	`entity.Label = label;`
`103`	`103`	`entityLabelCache[entity] = label;`
`104`	`104`
`105`		`- DefineLabel(entity, TrapWriter.Writer);`
	`105`	`+ DefineLabel(entity, TrapWriter.Writer, Extractor);`
`106`	`106`
`107`	`107`	`if (entity.NeedsPopulation)`
`108`	`108`	`Populate(init as ISymbol, entity);`
`@@ -148,7 +148,7 @@ private Entity CreateNonNullEntity<Type, Entity>(ICachedEntityFactory<Type, Enti`
`148`	`148`
`149`	`149`	`objectEntityCache[init] = entity;`
`150`	`150`
`151`		`- DefineLabel(entity, TrapWriter.Writer);`
	`151`	`+ DefineLabel(entity, TrapWriter.Writer, Extractor);`
`152`	`152`	`if (entity.NeedsPopulation)`
`153`	`153`	`Populate(init as ISymbol, entity);`
`154`	`154`