Fix symbols with missing properties

Author: dudikeleti

tracer/src/Datadog.Trace/Debugger/Symbols/Model/Scope.cs

@@ -14,7 +14,7 @@ internal record struct Scope
 {
     [JsonProperty("scope_type")]
     [JsonConverter(typeof(StringEnumConverter), converterParameters: typeof(SnakeCaseNamingStrategy))]
-    internal ScopeType ScopeType { get; set; }
+    internal ScopeType? ScopeType { get; set; }
 
     [JsonProperty("name")]
     internal string? Name { get; set; }

tracer/src/Datadog.Trace/Debugger/Symbols/Model/Symbol.cs

@@ -20,10 +20,10 @@ internal record struct Symbol
 
     [JsonProperty("symbol_type")]
     [JsonConverter(typeof(StringEnumConverter), converterParameters: typeof(SnakeCaseNamingStrategy))]
-    internal SymbolType SymbolType { get; set; }
+    internal SymbolType? SymbolType { get; set; }
 
     [JsonProperty("line")]
-    internal int Line { get; set; }
+    internal int? Line { get; set; }
 
     [JsonProperty("language_specifics")]
     internal LanguageSpecifics? LanguageSpecifics { get; set; }

tracer/src/Datadog.Trace/Debugger/Symbols/SymbolExtractor.cs

@@ -408,6 +408,11 @@ private Symbol[] GetFieldSymbols(FieldDefinitionHandleCollection fieldsCollectio
                 }
 
                 var fieldName = Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.AsSpan(MetadataReader.GetString(fieldDef.Name));
+                if (fieldName.IsEmpty)
+                {
+                    continue;
+                }
+
                 if (fieldName[0] == '<')
                 {
                     // properties
@@ -418,13 +423,19 @@ private Symbol[] GetFieldSymbols(FieldDefinitionHandleCollection fieldsCollectio
                     }
                 }
 
+                var fieldNameAsString = fieldName.ToString();
+                if (string.IsNullOrEmpty(fieldNameAsString))
+                {
+                    continue;
+                }
+
                 var accessModifiers = (fieldDef.Attributes & System.Reflection.FieldAttributes.FieldAccessMask) > 0 ? new[] { MethodAccess[Convert.ToUInt16(fieldDef.Attributes & System.Reflection.FieldAttributes.FieldAccessMask)] } : null;
                 var fieldAttributes = ((int)fieldDef.Attributes & 0x0070) > 0 ? new[] { FieldAttributes[Convert.ToUInt16((int)fieldDef.Attributes & 0x0070)] } : null;
                 var ls = new LanguageSpecifics() { AccessModifiers = accessModifiers, Annotations = fieldAttributes };
 
                 fieldSymbols[index] = new Symbol
                 {
-                    Name = fieldName.ToString(),
+                    Name = fieldNameAsString,
                     Type = fieldTypeName,
                     SymbolType = ((fieldDef.Attributes & System.Reflection.FieldAttributes.Static) != 0) ? SymbolType.StaticField : SymbolType.Field,
                     Line = UnknownFieldAndArgLine,

tracer/src/Datadog.Trace/Debugger/Symbols/SymbolPdbExtractor.cs

@@ -157,6 +157,11 @@ protected override bool TryCreateMethodScopeForGeneratedMethod(MethodDefinition
             foreach (var fieldHandle in fields)
             {
                 var field = MetadataReader.GetFieldDefinition(fieldHandle);
+                if (field.Name.IsNil)
+                {
+                    continue;
+                }
+
                 var fieldName = MetadataReader.GetString(field.Name);
                 var span = Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.AsSpan(fieldName);
                 if (Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.IndexOf(span, generatedClassPrefix, StringComparison.Ordinal) == 0)
@@ -171,7 +176,7 @@ protected override bool TryCreateMethodScopeForGeneratedMethod(MethodDefinition
                 }
 
                 var localName = Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.AsSpan(MetadataReader.GetString(field.Name));
-                if (localName[0] != '<')
+                if (localName.IsEmpty || localName[0] != '<')
                 {
                     continue;
                 }
@@ -183,6 +188,10 @@ protected override bool TryCreateMethodScopeForGeneratedMethod(MethodDefinition
                 }
 
                 var name = localName.ToString();
+                if (string.IsNullOrEmpty(name))
+                {
+                    continue;
+                }
 
                 if (IsArgument(methodScope.Symbols, name, type))
                 {
@@ -229,6 +238,11 @@ protected override bool TryCreateMethodScopeForGeneratedMethod(MethodDefinition
             foreach (var local in localScope.Locals)
             {
                 var nameAsSpan = Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.AsSpan(local.Name);
+                if (nameAsSpan.IsEmpty)
+                {
+                    continue;
+                }
+
                 if (Datadog.Trace.VendoredMicrosoftCode.System.MemoryExtensions.IndexOf(nameAsSpan, generatedClassPrefix, StringComparison.Ordinal) > 0)
                 {
                     var cdi = DatadogMetadataReader.GetAsyncAndClosureCustomDebugInfo(rowId);