Sorted out log levels for syntax errors.

Author: MDoerner

Rubberduck.Parsing/Symbols/SyntaxErrorException.cs

@@ -1,6 +1,5 @@
 using System;
 using Antlr4.Runtime;
-using NLog;
 
 namespace Rubberduck.Parsing.Symbols
 {
@@ -11,8 +10,6 @@ namespace Rubberduck.Parsing.Symbols
     [Serializable]
     public class SyntaxErrorException : Exception
     {
-        private static readonly Logger Logger = LogManager.GetCurrentClassLogger();
-
         public SyntaxErrorException(SyntaxErrorInfo info)
             : this(info.Message, info.Exception, info.OffendingSymbol, info.LineNumber, info.Position) { }
 
@@ -22,17 +19,27 @@ public SyntaxErrorException(string message, RecognitionException innerException,
             _token = offendingSymbol;
             _line = line;
             _position = position;
-            Logger.Debug(innerException == null ? "" : innerException.ToString());
-            Logger.Debug("Token: {0} (L{1}C{2})", offendingSymbol.Text, line, position);
+            _innerException = innerException;
         }
 
         private readonly IToken _token;
-        public IToken OffendingSymbol { get { return _token; } }
+        public IToken OffendingSymbol => _token;
 
         private readonly int _line;
-        public int LineNumber { get { return _line; } }
+        public int LineNumber => _line;
 
         private readonly int _position;
-        public int Position { get { return _position; } }
+        public int Position => _position;
+
+        private readonly RecognitionException _innerException;
+
+        public override string ToString()
+        {
+            var exceptionText = 
+$@"RecognitionException: {_innerException?.ToString() ?? string.Empty}
+Token: {_token.Text} (L{_line}C{_position})
+{base.ToString()}";
+            return exceptionText;
+        }
     }
 }

Rubberduck.Parsing/VBA/ComponentParseTask.cs

@@ -87,7 +87,7 @@ public void Start(CancellationToken cancellationToken)
             }
             catch (COMException exception)
             {
-                Logger.Error(exception, $"Exception thrown in thread {Thread.CurrentThread.ManagedThreadId} while parsing module {_qualifiedName.Name}, ParseTaskID {_taskId}.");
+                Logger.Error(exception, $"COM Exception thrown in thread {Thread.CurrentThread.ManagedThreadId} while parsing module {_qualifiedName.Name}, ParseTaskID {_taskId}.");
                 var failedHandler = ParseFailure;
                 failedHandler?.Invoke(this, new ParseFailureArgs
                 {
@@ -96,8 +96,8 @@ public void Start(CancellationToken cancellationToken)
             }
             catch (SyntaxErrorException exception)
             {
-                Logger.Warn($"Syntax error; offending token '{exception.OffendingSymbol.Text}' at line {exception.LineNumber}, column {exception.Position} in module {_qualifiedName}.");
-                Logger.Error(exception, $"Exception thrown in thread {Thread.CurrentThread.ManagedThreadId}, ParseTaskID {_taskId}.");
+                Logger.Error($"Syntax error; offending token '{exception.OffendingSymbol.Text}' at line {exception.LineNumber}, column {exception.Position} in module {_qualifiedName}.");
+                Logger.Debug(exception, $"SyntaxErrorException thrown in thread {Thread.CurrentThread.ManagedThreadId}, ParseTaskID {_taskId}.");
                 var failedHandler = ParseFailure;
                 failedHandler?.Invoke(this, new ParseFailureArgs
                 {
@@ -115,7 +115,7 @@ public void Start(CancellationToken cancellationToken)
             }
             catch (Exception exception)
             {
-                Logger.Error(exception, $"Exception thrown in thread {Thread.CurrentThread.ManagedThreadId} while parsing module {_qualifiedName.Name}, ParseTaskID {_taskId}.");
+                Logger.Error(exception, $" Unexpected exception thrown in thread {Thread.CurrentThread.ManagedThreadId} while parsing module {_qualifiedName.Name}, ParseTaskID {_taskId}.");
                 var failedHandler = ParseFailure;
                 failedHandler?.Invoke(this, new ParseFailureArgs
                 {

Rubberduck.Parsing/VBA/VBAModuleParser.cs

@@ -4,6 +4,7 @@
 using NLog;
 using Rubberduck.Parsing.Grammar;
 using System;
+using Rubberduck.Parsing.Symbols;
 
 namespace Rubberduck.Parsing.VBA
 {
@@ -22,9 +23,19 @@ public sealed class VBAModuleParser
                 parser.Interpreter.PredictionMode = PredictionMode.Sll;
                 tree = parser.startRule();
             }
-            catch (Exception ex)
+            catch (SyntaxErrorException syntaxErrorException)
             {
-                Logger.Warn(ex, "SLL mode failed in module {0}. Retrying using LL.", moduleName);
+                Logger.Warn($"SLL mode failed in module {moduleName} at symbol {syntaxErrorException.OffendingSymbol.Text} at L{syntaxErrorException.LineNumber}C{syntaxErrorException.Position}. Retrying using LL.");
+                Logger.Debug(syntaxErrorException, "SLL mode exception");
+                moduleTokens.Reset();
+                parser.Reset();
+                parser.Interpreter.PredictionMode = PredictionMode.Ll;
+                tree = parser.startRule();
+            }
+            catch (Exception exception)
+            {
+                Logger.Warn($"SLL mode failed in module {moduleName}. Retrying using LL.");
+                Logger.Debug(exception, "SLL mode exception");
                 moduleTokens.Reset();
                 parser.Reset();
                 parser.Interpreter.PredictionMode = PredictionMode.Ll;