Beispiel #1
0
        /// <summary>
        /// Incremental parsing of a set of processed tokens lines changes
        /// </summary>
        internal static IList <DocumentChange <ICodeElementsLine> > ParseProcessedTokensLinesChanges(TextSourceInfo textSourceInfo, ISearchableReadOnlyList <CodeElementsLine> documentLines, IList <DocumentChange <IProcessedTokensLine> > processedTokensLinesChanges, PrepareDocumentLineForUpdate prepareDocumentLineForUpdate, TypeCobolOptions compilerOptions)
        {
            // Collect all changes applied to the processed tokens lines during the incremental scan
            IList <DocumentChange <ICodeElementsLine> > codeElementsLinesChanges = new List <DocumentChange <ICodeElementsLine> >();

            // There are 2 reasons to re-parse a tokens line after a change :
            // 1. The tokens line changed : these lines were already reset during the previous steps
            // 2. If a tokens line that changed was involved in the parsing of a multiline code element, the whole group of lines must be parsed again

            // --- PREPARATION PHASE : identify all parse sections where code elements need to be refreshed ---

            IList <ParseSection> refreshParseSections = null;

            // Iterate over all processed tokens changes detected by the PreprocessorStep :
            // - refresh all the adjacent lines participating in a CodeElement
            // - register the start and stop token for all sections of the document which need to be parsed again
            if (processedTokensLinesChanges != null)
            {
                // If the document was cleared, everything must be parsed again
                if (processedTokensLinesChanges[0].Type != DocumentChangeType.DocumentCleared)
                {
                    refreshParseSections = new List <ParseSection>();

                    ParseSection lastParseSection = null;
                    foreach (DocumentChange <IProcessedTokensLine> tokensChange in processedTokensLinesChanges)
                    {
                        if (lastParseSection == null || tokensChange.LineIndex > lastParseSection.StopLineIndex)
                        {
                            lastParseSection = CheckIfAdjacentLinesNeedRefresh(tokensChange.Type, tokensChange.LineIndex, documentLines, prepareDocumentLineForUpdate, codeElementsLinesChanges, lastParseSection);
                            refreshParseSections.Add(lastParseSection);
                        }
                    }
                }
            }

            // --- INITIALIZE ANTLR CodeElements parser ---

            // Create a token iterator on top of pre-processed tokens lines
            ITokensLinesIterator tokensIterator = ProcessedTokensDocument.GetProcessedTokensIterator(textSourceInfo, documentLines);

            // Create an Antlr compatible token source on top of the token iterator
            TokensLinesTokenSource tokenSource = new TokensLinesTokenSource(
                textSourceInfo.Name,
                tokensIterator);

            // Init parser
            TokensLinesTokenStream tokenStream = new TokensLinesTokenStream(tokenSource, Token.CHANNEL_SourceTokens);
            CodeElementsParser     cobolParser = new CodeElementsParser(tokenStream);
            // REVERT TO STD PARSER ==> TracingCobolParser cobolParser = new TracingCobolParser(tokenStream);

            // Customize error recovery strategy
            IAntlrErrorStrategy cobolErrorStrategy = new CodeElementErrorStrategy();

            cobolParser.ErrorHandler = cobolErrorStrategy;

            // Register all parse errors in a list in memory
            ParserDiagnosticErrorListener errorListener = new ParserDiagnosticErrorListener();

            cobolParser.RemoveErrorListeners();
            cobolParser.AddErrorListener(errorListener);

            // Prepare to analyze the parse tree
            ParseTreeWalker    walker             = new ParseTreeWalker();
            CodeElementBuilder codeElementBuilder = new CodeElementBuilder();

            codeElementBuilder.Dispatcher = new CodeElementDispatcher();
            codeElementBuilder.Dispatcher.CreateListeners();

            // --- INCREMENTAL PARSING ---

            // In case of incremental parsing, parse only the code sections we need to refresh
            IEnumerator <ParseSection> parseSectionsEnumerator = null;
            ParseSection currentParseSection = null;

            if (refreshParseSections != null)
            {
                // Get the first code section we need to refresh
                parseSectionsEnumerator = refreshParseSections.GetEnumerator();
                parseSectionsEnumerator.MoveNext();
                currentParseSection = parseSectionsEnumerator.Current;

                // Seek just before the next code element starting token
                tokenStream.SeekToToken(currentParseSection.StartToken);
                tokenStream.StartLookingForStopToken(currentParseSection.StopToken);
            }

            // Parse a list of code elements for each parse section while advancing in the underlying token stream
            do
            {
                // Reset parsing error diagnostics
                cobolErrorStrategy.Reset(cobolParser);

                // Try to parse code elements :
                // - starting with the current parse section Start token
                // - ending with the current parse section Stop token
                CodeElementsParser.CobolCodeElementsContext codeElementsParseTree = null;
                try {
                    codeElementsParseTree = cobolParser.cobolCodeElements();
                } catch (Exception e) {
                    var currentToken = (Token)cobolParser.CurrentToken;
                    CodeElementsLine codeElementsLine = GetCodeElementsLineForToken(currentToken);
                    codeElementsLine.AddParserDiagnostic(new TokenDiagnostic(MessageCode.ImplementationError, currentToken, currentToken.Line, e));
                }

                if (codeElementsParseTree != null)
                {
                    // If the parse tree is not empty
                    if (codeElementsParseTree.codeElement() != null && codeElementsParseTree.codeElement().Length > 0)
                    {
                        // Analyze the parse tree for each code element
                        foreach (var codeElementParseTree in codeElementsParseTree.codeElement())
                        {
                            // Get the first line that was parsed
                            var tokenStart = (Token)codeElementParseTree.Start;
                            CodeElementsLine codeElementsLine = GetCodeElementsLineForToken(tokenStart);

                            // Register that this line was updated
                            // COMMENTED FOR THE SAKE OF PERFORMANCE -- SEE ISSUE #160
                            //int updatedLineIndex = documentLines.IndexOf(codeElementsLine, codeElementsLine.InitialLineIndex);
                            //codeElementsLinesChanges.Add(new DocumentChange<ICodeElementsLine>(DocumentChangeType.LineUpdated, updatedLineIndex, codeElementsLine));
                            codeElementsLinesChanges.Add(new DocumentChange <ICodeElementsLine>(DocumentChangeType.LineUpdated, codeElementsLine.InitialLineIndex, codeElementsLine));

                            // Visit the parse tree to build a first class object representing the code elements
                            try { walker.Walk(codeElementBuilder, codeElementParseTree); }
                            catch (Exception ex)
                            {
                                var code = MessageCode.ImplementationError;
                                int line = 0; int start = 0; int stop = 0;
                                if (codeElementsLine.SourceTokens != null && codeElementsLine.SourceTokens.Count > 0)
                                {
                                    start = codeElementsLine.SourceTokens[0].StartIndex;
                                    stop  = codeElementsLine.SourceTokens[codeElementsLine.SourceTokens.Count - 1].StopIndex;
                                }
                                codeElementsLine.AddParserDiagnostic(new ParserDiagnostic(ex.ToString(), start, stop, line, null, code));
                            }
                            CodeElement codeElement = codeElementBuilder.CodeElement;
                            if (codeElement != null)
                            {
                                // Attach consumed tokens and main document line numbers information to the code element
                                if (codeElement.ConsumedTokens.Count == 0)
                                {     // ISSUE #204:
                                    if (tokenStream.Lt(1) != null)
                                    { // if not end of file,
                                        // add next token to ConsumedTokens to know where is the CodeElement in error
                                        codeElement.ConsumedTokens.Add((Token)tokenStream.Lt(1));
                                        // this alter CodeElements semantics: in addition to matched tokens,
                                        // it includes the first token in error if no token has been matched
                                    }
                                }

                                //TODO Issue #384 to discuss if this code should stay here:
                                //This should be in a Checker, but "codeElement.ConsumedTokens" is only set after all the checkers have been called
                                //Rule TCLIMITATION_NO_CE_ACROSS_SOURCES
                                if (codeElement.IsAcrossSourceFile())
                                {
                                    DiagnosticUtils.AddError(codeElement, "A Cobol statement cannot be across 2 sources files (eg. Main program and a COPY)", MessageCode.TypeCobolParserLimitation);
                                }

                                // Add code element to the list
                                codeElementsLine.AddCodeElement(codeElement);
                                if (codeElement.Diagnostics != null)
                                {
                                    foreach (Diagnostic d in codeElement.Diagnostics)
                                    {
                                        codeElementsLine.AddParserDiagnostic(d);
                                    }
                                }
                            }
                        }
                    }
                    // If the parse tree contains errors
                    if (codeElementsParseTree.Diagnostics != null)
                    {
                        foreach (ParserDiagnostic d in codeElementsParseTree.Diagnostics)
                        {
                            if (d.OffendingSymbol != null)
                            {
                                CodeElementsLine codeElementsLine = GetCodeElementsLineForToken((Token)d.OffendingSymbol);
                                codeElementsLine.AddParserDiagnostic(d);
                            }
                        }
                    }
                }

                // In case of incremental parsing, directly jump to next parse section in the token stream
                // Else, simply start parsing the next CodeElement beginning with the next token
                if (currentParseSection != null)
                {
                    // Adavance to the next ParseSection
                    if (parseSectionsEnumerator.MoveNext())
                    {
                        currentParseSection = parseSectionsEnumerator.Current;
                        tokenStream.SeekToToken(currentParseSection.StartToken);
                        tokenStream.StartLookingForStopToken(currentParseSection.StopToken);
                    }
                    // No more section to parse
                    else
                    {
                        break;
                    }
                }
            }while (tokenStream.La(1) >= 0);

            return(codeElementsLinesChanges);
        }
Beispiel #2
0
        /// <summary>
        /// Incremental parsing of a set of processed tokens lines changes
        /// </summary>
        internal static IList <DocumentChange <ICodeElementsLine> > ParseProcessedTokensLinesChanges(TextSourceInfo textSourceInfo, ISearchableReadOnlyList <CodeElementsLine> documentLines, IList <DocumentChange <IProcessedTokensLine> > processedTokensLinesChanges, PrepareDocumentLineForUpdate prepareDocumentLineForUpdate, TypeCobolOptions compilerOptions, PerfStatsForParserInvocation perfStatsForParserInvocation)
        {
            // Collect all changes applied to the processed tokens lines during the incremental scan
            IList <DocumentChange <ICodeElementsLine> > codeElementsLinesChanges = new List <DocumentChange <ICodeElementsLine> >();

            // There are 2 reasons to re-parse a tokens line after a change :
            // 1. The tokens line changed : these lines were already reset during the previous steps
            // 2. If a tokens line that changed was involved in the parsing of a multiline code element, the whole group of lines must be parsed again

            // --- PREPARATION PHASE : identify all parse sections where code elements need to be refreshed ---

            IList <ParseSection> refreshParseSections       = null;
            ParseSection         largestRefreshParseSection = null;

            // Iterate over all processed tokens changes detected by the PreprocessorStep :
            // - refresh all the adjacent lines participating in a CodeElement
            // - register the start and stop token for all sections of the document which need to be parsed again
            if (processedTokensLinesChanges != null && processedTokensLinesChanges.Count > 0)
            {
                // If the document was cleared, everything must be parsed again
                if (processedTokensLinesChanges[0].Type != DocumentChangeType.DocumentCleared)
                {
                    refreshParseSections = new List <ParseSection>();

                    ParseSection lastParseSection = null;
                    foreach (DocumentChange <IProcessedTokensLine> tokensChange in processedTokensLinesChanges)
                    {
                        if (lastParseSection == null || tokensChange.LineIndex > lastParseSection.StopLineIndex)
                        {
                            lastParseSection = CheckIfAdjacentLinesNeedRefresh(tokensChange.Type, tokensChange.LineIndex, documentLines, prepareDocumentLineForUpdate, codeElementsLinesChanges, lastParseSection);
                            refreshParseSections.Add(lastParseSection);
                        }
                    }
                }
            }
            if (refreshParseSections != null)
            {
                //After getting all the parts refreshed, get the largest part that has been refreshed
                var minParseSection = refreshParseSections.OrderBy(p => p.StartLineIndex).First();
                var maxParseSection = refreshParseSections.OrderByDescending(p => p.StopLineIndex).First();
                largestRefreshParseSection = new ParseSection(minParseSection.StartLineIndex,
                                                              minParseSection.StartToken, maxParseSection.StopLineIndex, maxParseSection.StopToken,
                                                              maxParseSection.StopTokenIsFirstTokenOfTheLine);
            }


            // --- INITIALIZE ANTLR CodeElements parser ---

            // Create a token iterator on top of pre-processed tokens lines
            ITokensLinesIterator tokensIterator = ProcessedTokensDocument.GetProcessedTokensIterator(textSourceInfo, documentLines);

            // Create an Antlr compatible token source on top of the token iterator
            TokensLinesTokenSource tokenSource = new TokensLinesTokenSource(
                textSourceInfo.Name,
                tokensIterator);

            // Init parser
            TokensLinesTokenStream tokenStream = new TokensLinesTokenStream(tokenSource, Token.CHANNEL_SourceTokens);
            CodeElementsParser     cobolParser = new CodeElementsParser(tokenStream);

            // REVERT TO STD PARSER ==> TracingCobolParser cobolParser = new TracingCobolParser(tokenStream);

            // Optionnaly activate Antlr Parser performance profiling
            // WARNING : use this in a single-treaded context only (uses static field)
            if (AntlrPerformanceProfiler == null && perfStatsForParserInvocation.ActivateDetailedAntlrPofiling)
            {
                AntlrPerformanceProfiler = new AntlrPerformanceProfiler(cobolParser);
            }
            if (AntlrPerformanceProfiler != null)
            {
                // Replace the generated parser by a subclass which traces all rules invocations
                cobolParser = new CodeElementsTracingParser(tokenStream);

                var tokensCountIterator = ProcessedTokensDocument.GetProcessedTokensIterator(textSourceInfo, documentLines);
                AntlrPerformanceProfiler.BeginParsingFile(textSourceInfo, tokensCountIterator);
            }

            // Customize error recovery strategy
            IAntlrErrorStrategy cobolErrorStrategy = new CodeElementErrorStrategy();

            cobolParser.ErrorHandler = cobolErrorStrategy;

            // Register all parse errors in a list in memory
            ParserDiagnosticErrorListener errorListener = new ParserDiagnosticErrorListener();

            cobolParser.RemoveErrorListeners();
            cobolParser.AddErrorListener(errorListener);

            // Prepare to analyze the parse tree
            ParseTreeWalker    walker             = new ParseTreeWalker();
            CodeElementBuilder codeElementBuilder = new CodeElementBuilder();

            codeElementBuilder.Dispatcher = new CodeElementDispatcher();
            codeElementBuilder.Dispatcher.CreateListeners();

            // --- INCREMENTAL PARSING ---

            // In case of incremental parsing, parse only the code sections we need to refresh

            if (largestRefreshParseSection != null)
            {
                // Seek just before the next code element starting token
                tokenStream.SeekToToken(largestRefreshParseSection.StartToken);
                tokenStream.StartLookingForStopToken(largestRefreshParseSection.StopToken);

                //Remove all the code elements for the future line to parse.

                for (int i = largestRefreshParseSection.StartLineIndex;
                     i < (largestRefreshParseSection.StopLineIndex == documentLines.Count - 1 && largestRefreshParseSection.StopToken == null //If the last index is equals to number of line in document, make sure to also reset the last line, otherwise, reset lines normally.
                        ? largestRefreshParseSection.StopLineIndex + 1
                        : largestRefreshParseSection.StopLineIndex);
                     i++)
                {
                    if (documentLines[i].CodeElements != null)
                    {
                        documentLines[i].ResetCodeElements();
                    }
                }
            }



            // Reset parsing error diagnostics
            cobolErrorStrategy.Reset(cobolParser);

            // Try to parse code elements :
            // - starting with the current parse section Start token
            // - ending with the current parse section Stop token
            CodeElementsParser.CobolCodeElementsContext codeElementsParseTree = null;
            try
            {
                perfStatsForParserInvocation.OnStartAntlrParsing();
                if (AntlrPerformanceProfiler != null)
                {
                    AntlrPerformanceProfiler.BeginParsingSection();
                }
                codeElementsParseTree = cobolParser.cobolCodeElements();
                if (AntlrPerformanceProfiler != null)
                {
                    AntlrPerformanceProfiler.EndParsingSection(codeElementsParseTree.ChildCount);
                }
                perfStatsForParserInvocation.OnStopAntlrParsing(
                    AntlrPerformanceProfiler != null
                        ? (int)AntlrPerformanceProfiler.CurrentFileInfo.DecisionTimeMs
                        : 0,
                    AntlrPerformanceProfiler != null
                        ? AntlrPerformanceProfiler.CurrentFileInfo.RuleInvocations.Sum()
                        : 0);
            }
            catch (Exception e)
            {
                var currentToken = (Token)cobolParser.CurrentToken;
                CodeElementsLine codeElementsLine = GetCodeElementsLineForToken(currentToken);
                if (codeElementsLine != null)
                {
                    codeElementsLine.AddParserDiagnostic(new TokenDiagnostic(MessageCode.ImplementationError,
                                                                             currentToken, currentToken.Line, e));
                }
            }

            if (codeElementsParseTree != null)
            {
                // If the parse tree is not empty
                if (codeElementsParseTree.codeElement() != null && codeElementsParseTree.codeElement().Length > 0)
                {
                    // Analyze the parse tree for each code element
                    foreach (var codeElementParseTree in codeElementsParseTree.codeElement())
                    {
                        // Get the first line that was parsed
                        var tokenStart = (Token)codeElementParseTree.Start;
                        CodeElementsLine codeElementsLine = GetCodeElementsLineForToken(tokenStart);
                        if (codeElementsLine == null)
                        {
                            continue;
                        }

                        // Register that this line was updated
                        // COMMENTED FOR THE SAKE OF PERFORMANCE -- SEE ISSUE #160
                        //int updatedLineIndex = documentLines.IndexOf(codeElementsLine, codeElementsLine.LineIndex);
                        //codeElementsLinesChanges.Add(new DocumentChange<ICodeElementsLine>(DocumentChangeType.LineUpdated, updatedLineIndex, codeElementsLine));
                        codeElementsLinesChanges.Add(
                            new DocumentChange <ICodeElementsLine>(DocumentChangeType.LineUpdated,
                                                                   codeElementsLine.LineIndex, codeElementsLine));

                        perfStatsForParserInvocation.OnStartTreeBuilding();
                        // Visit the parse tree to build a first class object representing the code elements
                        try
                        {
                            walker.Walk(codeElementBuilder, codeElementParseTree);
                        }
                        catch (Exception ex)
                        {
                            var code  = MessageCode.ImplementationError;
                            int line  = 0;
                            int start = 0;
                            int stop  = 0;
                            if (codeElementsLine.SourceTokens != null && codeElementsLine.SourceTokens.Count > 0)
                            {
                                start = codeElementsLine.SourceTokens[0].StartIndex;
                                stop  =
                                    codeElementsLine.SourceTokens[codeElementsLine.SourceTokens.Count - 1].StopIndex;
                            }
                            codeElementsLine.AddParserDiagnostic(new ParserDiagnostic(ex.ToString(), start, stop,
                                                                                      line, null, code, ex));
                        }
                        CodeElement codeElement = codeElementBuilder.CodeElement;
                        if (codeElement != null)
                        {
                            // Attach consumed tokens and main document line numbers information to the code element
                            if (codeElement.ConsumedTokens.Count == 0)
                            {
// ISSUE #204:
                                var tempToken = tokenStream.Lt(1);
                                if (tempToken != null && tempToken != Token.END_OF_FILE)
                                {
// if not end of file,
                                    // add next token to ConsumedTokens to know where is the CodeElement in error
                                    codeElement.ConsumedTokens.Add((Token)tempToken);
                                    // this alter CodeElements semantics: in addition to matched tokens,
                                    // it includes the first token in error if no token has been matched
                                }
                            }

                            //TODO Issue #384 to discuss if this code should stay here:
                            //This should be in a Checker, but "codeElement.ConsumedTokens" is only set after all the checkers have been called
                            //Rule TCLIMITATION_NO_CE_ACROSS_SOURCES
                            if (codeElement.IsAcrossSourceFile())
                            {
                                DiagnosticUtils.AddError(codeElement,
                                                         "A Cobol statement cannot be across 2 sources files (eg. Main program and a COPY)",
                                                         MessageCode.TypeCobolParserLimitation);
                            }

                            // Add code element to the list
                            codeElementsLine.AddCodeElement(codeElement);
                        }
                    }
                }
                // If the parse tree contains errors
                if (codeElementsParseTree.Diagnostics != null)
                {
                    foreach (ParserDiagnostic d in codeElementsParseTree.Diagnostics)
                    {
                        if (d.OffendingSymbol != null)
                        {
                            CodeElementsLine codeElementsLine =
                                GetCodeElementsLineForToken((Token)d.OffendingSymbol);
                            if (codeElementsLine != null)
                            {
                                codeElementsLine.AddParserDiagnostic(d);
                            }
                        }
                    }
                }
                perfStatsForParserInvocation.OnStopTreeBuilding();
            }


            if (AntlrPerformanceProfiler != null)
            {
                AntlrPerformanceProfiler.EndParsingFile(cobolParser.ParseInfo.DecisionInfo, (int)(cobolParser.ParseInfo.GetTotalTimeInPrediction() / 1000000));
            }

            return(codeElementsLinesChanges);
        }
        /// <summary>
        /// Incremental parsing of a set of processed tokens lines changes
        /// </summary>
        internal static IList<DocumentChange<ICodeElementsLine>> ParseProcessedTokensLinesChanges(TextSourceInfo textSourceInfo, ISearchableReadOnlyList<CodeElementsLine> documentLines, IList<DocumentChange<IProcessedTokensLine>> processedTokensLinesChanges, PrepareDocumentLineForUpdate prepareDocumentLineForUpdate, TypeCobolOptions compilerOptions)
        {
            // Collect all changes applied to the processed tokens lines during the incremental scan
            IList<DocumentChange<ICodeElementsLine>> codeElementsLinesChanges = new List<DocumentChange<ICodeElementsLine>>();

            // There are 2 reasons to re-parse a tokens line after a change :
            // 1. The tokens line changed : these lines were already reset during the previous steps
            // 2. If a tokens line that changed was involved in the parsing of a multiline code element, the whole group of lines must be parsed again

            // --- PREPARATION PHASE : identify all parse sections where code elements need to be refreshed ---

            IList<ParseSection> refreshParseSections = null;

            // Iterate over all processed tokens changes detected by the PreprocessorStep :
            // - refresh all the adjacent lines participating in a CodeElement
            // - register the start and stop token for all sections of the document which need to be parsed again
            if (processedTokensLinesChanges != null)
            {
                // If the document was cleared, everything must be parsed again
                if (processedTokensLinesChanges[0].Type != DocumentChangeType.DocumentCleared)
                {
                    refreshParseSections = new List<ParseSection>();

                    ParseSection lastParseSection = null;
                    foreach (DocumentChange<IProcessedTokensLine> tokensChange in processedTokensLinesChanges)
                    {
                        if (lastParseSection == null || tokensChange.LineIndex > lastParseSection.StopLineIndex)
                        {
                            lastParseSection = CheckIfAdjacentLinesNeedRefresh(tokensChange.Type, tokensChange.LineIndex, documentLines, prepareDocumentLineForUpdate, codeElementsLinesChanges, lastParseSection);
                            refreshParseSections.Add(lastParseSection);
                        }
                    }
                }
            }

            // --- INITIALIZE ANTLR CodeElements parser ---

            // Create a token iterator on top of pre-processed tokens lines
            ITokensLinesIterator tokensIterator = ProcessedTokensDocument.GetProcessedTokensIterator(textSourceInfo, documentLines);

            // Create an Antlr compatible token source on top of the token iterator
            TokensLinesTokenSource tokenSource = new TokensLinesTokenSource(
                textSourceInfo.Name,
                tokensIterator);

            // Init parser
            TokensLinesTokenStream tokenStream = new TokensLinesTokenStream(tokenSource, Token.CHANNEL_SourceTokens);
            TracingCobolParser cobolParser = new TracingCobolParser(tokenStream);
            // -> activate full ambiguities detection
            //parser.Interpreter.PredictionMode = PredictionMode.LlExactAmbigDetection;
            IAntlrErrorStrategy cobolErrorStrategy = new CobolErrorStrategy();
            cobolParser.ErrorHandler = cobolErrorStrategy;

            // Register all parse errors in a list in memory
            DiagnosticSyntaxErrorListener errorListener = new DiagnosticSyntaxErrorListener();
            cobolParser.RemoveErrorListeners();
            cobolParser.AddErrorListener(errorListener);

            // Prepare to analyze the parse tree
            ParseTreeWalker walker = new ParseTreeWalker();
            CodeElementBuilder codeElementBuilder = new CodeElementBuilder();
            codeElementBuilder.Dispatcher = new CodeElementDispatcher();
            codeElementBuilder.Dispatcher.CreateListeners();

            // --- INCREMENTAL PARSING ---

            // In case of incremental parsing, parse only the code sections we need to refresh
            IEnumerator<ParseSection> parseSectionsEnumerator = null;
            ParseSection currentParseSection = null;
            if (refreshParseSections != null)
            {
                // Get the first code section we need to refresh
                parseSectionsEnumerator = refreshParseSections.GetEnumerator();
                parseSectionsEnumerator.MoveNext();
                currentParseSection = parseSectionsEnumerator.Current;

                // Seek just before the next code element starting token
                tokenStream.SeekToToken(currentParseSection.StartToken);
                tokenStream.StartLookingForStopToken(currentParseSection.StopToken);
            }

            // Parse one CodeElement at a time while advancing in the underlying token stream
            do
            {
                // Reset parsing error diagnostics
                //cobolErrorStrategy.Reset(cobolParser);
                errorListener.Diagnostics.Clear();

                // Reset parser traces (consumed tokens)
                cobolParser.ResetTraces();

                // Try to parse a code element starting with the current token
                CodeElementsParser.CodeElementContext codeElementParseTree = cobolParser.codeElement();

                // If the parse tree is not empty
                if (codeElementParseTree.Start.Type > 0)
                {
                    // Get the first line that was parsed
                    var tokenStart = (Token)codeElementParseTree.Start;
                    CodeElementsLine codeElementsLine;

                    var importedToken = tokenStart as ImportedToken;
                    if (importedToken != null)
                    {
                        codeElementsLine = (CodeElementsLine) importedToken.CopyDirective.TextNameSymbol.TokensLine;
                    }
                    else
                    {
                        codeElementsLine = ((CodeElementsLine) tokenStart.TokensLine);
                    }

                    // Register that this line was updated
                    // COMMENTED FOR THE SAKE OF PERFORMANCE -- SEE ISSUE #160
                    //int updatedLineIndex = documentLines.IndexOf(codeElementsLine, codeElementsLine.InitialLineIndex);
                    //codeElementsLinesChanges.Add(new DocumentChange<ICodeElementsLine>(DocumentChangeType.LineUpdated, updatedLineIndex, codeElementsLine));
                    codeElementsLinesChanges.Add(new DocumentChange<ICodeElementsLine>(DocumentChangeType.LineUpdated, codeElementsLine.InitialLineIndex, codeElementsLine));

                    // Visit the parse tree to build a first class object representing the code elements
                    try { walker.Walk(codeElementBuilder, codeElementParseTree); }
                    catch (Exception ex) {
                        var code = Diagnostics.MessageCode.ImplementationError;
                        int line = 0; int start = 0; int stop = 0;
                        if (codeElementsLine.SourceTokens != null && codeElementsLine.SourceTokens.Count > 0){
                            start = codeElementsLine.SourceTokens[0].StartIndex;
                            stop = codeElementsLine.SourceTokens[codeElementsLine.SourceTokens.Count-1].StopIndex;
                        }
                        codeElementsLine.AddParserDiagnostic(new ParserDiagnostic(ex.ToString(), start,stop,line, null, code));
                    }
                    CodeElement codeElement = codeElementBuilder.CodeElement;
                    if (codeElement != null)
                    {
                        // Attach consumed tokens and main document line numbers information to the code element
                        codeElement.ConsumedTokens = cobolParser.ConsumedTokens;
                        if (codeElement.ConsumedTokens == null) {// ISSUE #204:
                            if (tokenStream.Lt(1) != null) {// if not end of file,
                                // add next token to ConsumedTokens to know where is the CodeElement in error
                                codeElement.ConsumedTokens.Add((Token)tokenStream.Lt(1));
                                // this alter CodeElements semantics: in addition to matched tokens,
                                // it includes the first token in error if no token has been matched
                            }
                        }

                        //TODO Issue #384 to discuss if this code should stay here:
                        //This should be in a Checker, but "codeElement.ConsumedTokens" is only set after all the checkers have been called
                        //Rule TCLIMITATION_NO_CE_ACROSS_SOURCES
                        if (codeElement.IsAcrossSourceFile()) {
                            DiagnosticUtils.AddError(codeElement, "A Cobol statement cannot be across 2 sources files (eg. Main program and a COPY)", MessageCode.TypeCobolParserLimitation);
                        }

                        // Add code element to the list
                        codeElementsLine.AddCodeElement(codeElement);
                        foreach (ParserDiagnostic d in errorListener.Diagnostics)
                        {
                            codeElement.Diagnostics.Add(d);
                        }
                        foreach (Diagnostic d in codeElement.Diagnostics)
                        {
                            codeElementsLine.AddParserDiagnostic(d);
                        }
                    }
                    else
                    {
                        foreach (ParserDiagnostic d in errorListener.Diagnostics)
                        {
                            codeElementsLine.AddParserDiagnostic(d);
                        }
                    }
                }

                // In case of incremental parsing, directly jump to next parse section in the token stream
                // Else, simply start parsing the next CodeElement beginning with the next token
                if (currentParseSection != null)
                {
                    // Check if we reached the end of the current ParseSection
                    if (tokenStream.StreamReachedStopToken)
                    {

                        // Adavance to the next ParseSection
                        if (parseSectionsEnumerator.MoveNext())
                        {
                            currentParseSection = parseSectionsEnumerator.Current;
                            tokenStream.SeekToToken(currentParseSection.StartToken);
                            tokenStream.StartLookingForStopToken(currentParseSection.StopToken);
                        }
                        // No more section to parse
                        else
                        {
                            break;
                        }
                    }
                }
            }
            while (tokenStream.La(1) >= 0);

            return codeElementsLinesChanges;
        }