fixes #29095, machine mode escapes newline/returns

pkg/analyzer_cli/lib/src/error_formatter.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer_cli.src.error_formatter;
 
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer_cli/src/options.dart';
@@ skipping 90 matching lines @@
     }
   }
 }
 
 /// Helper for formatting [AnalysisError]s.
 /// The two format options are a user consumable format and a machine consumable
 /// format.
 class ErrorFormatter {
   static final int _pipeCodeUnit = '|'.codeUnitAt(0);
   static final int _slashCodeUnit = '\\'.codeUnitAt(0);
+  static final int _newline = '\n'.codeUnitAt(0);
+  static final int _return = '\r'.codeUnitAt(0);
 
   final StringSink out;
   final CommandLineOptions options;
   final AnalysisStats stats;
 
   final _SeverityProcessor processSeverity;
 
   ErrorFormatter(this.out, this.options, this.stats,
       [this.processSeverity = _identity]);
 
@@ skipping 16 matching lines @@
         if (severity == ErrorSeverity.WARNING && options.warningsAreFatal) {
           severity = ErrorSeverity.ERROR;
         }
       }
       out.write(severity);
       out.write('|');
       out.write(error.errorCode.type);
       out.write('|');
       out.write(error.errorCode.name);
       out.write('|');
-      out.write(escapePipe(source.fullName));
+      out.write(escapeForMachineMode(source.fullName));
       out.write('|');
       out.write(location.lineNumber);
       out.write('|');
       out.write(location.columnNumber);
       out.write('|');
       out.write(length);
       out.write('|');
-      out.write(escapePipe(error.message));
+      out.write(escapeForMachineMode(error.message));
       out.writeln();
     } else {
       // Get display name.
       String errorType = severity.displayName;
 
       // Translate INFOs into LINTS and HINTS.
       if (severity == ErrorSeverity.INFO) {
         if (error.errorCode.type == ErrorType.HINT ||
             error.errorCode.type == ErrorType.LINT) {
           errorType = error.errorCode.type.displayName;
@@ skipping 79 matching lines @@
         }
       } else if (error.errorCode.type == ErrorType.HINT) {
         stats.hintCount++;
       } else if (error.errorCode.type == ErrorType.LINT) {
         stats.lintCount++;
       }
       formatError(errorToLine, error);
     }
   }
 
-  static String escapePipe(String input) {
+  static String escapeForMachineMode(String input) {
     StringBuffer result = new StringBuffer();
     for (int c in input.codeUnits) {
-      if (c == _slashCodeUnit || c == _pipeCodeUnit) {
-        result.write('\\');
+      if (c == _newline) {
+        result.write(r'\n');
+      } else if (c == _return) {
+        result.write(r'\r');
+      } else {
+        if (c == _slashCodeUnit || c == _pipeCodeUnit) {
+          result.write('\\');
+        }
+        result.writeCharCode(c);
       }
-      result.writeCharCode(c);
     }
     return result.toString();
   }
 }
 
 /// A severity with awareness of whether it was overridden by a processor.
 class ProcessedSeverity {
   ErrorSeverity severity;
   bool overridden;
   ProcessedSeverity(this.severity, [this.overridden = false]);
 }
 
 /// Given an absolute path, return a relative path if the file is contained in
 /// the current directory; return the original path otherwise.
 String _relative(String file) {
   return file.startsWith(path.current) ? path.relative(file) : file;
 }