add --x-package-warnings-prefix option to dartanalyzer

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/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer_cli/src/options.dart';
 
 /// Returns the given error's severity.
 ProcessedSeverity _identity(AnalysisError error) =>
     new ProcessedSeverity(error.errorCode.errorSeverity);
 
 String _pluralize(String word, int count) => count == 1 ? word : word + "s";
 
 /// Returns desired severity for the given [error] (or `null` if it's to be
 /// suppressed).
 typedef ProcessedSeverity _SeverityProcessor(AnalysisError error);
 
 /// Analysis statistics counter.
 class AnalysisStats {
+  /// The total number of diagnostics sent to [formatErrors].
+  int unfilteredCount;
+
   int errorCount;
   int hintCount;
   int lintCount;
   int warnCount;
 
   AnalysisStats() {
     init();
   }
 
+  /// The total number of diagnostics reported to the user.
+  int get filteredCount => errorCount + warnCount + hintCount + lintCount;
+
   /// (Re)set initial values.
   void init() {
+    unfilteredCount = 0;
     errorCount = 0;
     hintCount = 0;
     lintCount = 0;
     warnCount = 0;
   }
 
   /// Print statistics to [out].
   void print(StringSink out) {
     var hasErrors = errorCount != 0;
     var hasWarns = warnCount != 0;
@@ skipping 110 matching lines @@
 
       // [warning] 'foo' is not a... (/Users/.../tmp/foo.dart, line 1, col 2)
       out.write('[$errorType] ${error.message} ');
       out.write('(${source.fullName}');
       out.write(', line ${location.lineNumber}, col ${location.columnNumber})');
     }
     out.writeln();
   }
 
   void formatErrors(List<AnalysisErrorInfo> errorInfos) {
+    stats.unfilteredCount += errorInfos.length;
+
     var errors = new List<AnalysisError>();
     var errorToLine = new Map<AnalysisError, LineInfo>();
     for (AnalysisErrorInfo errorInfo in errorInfos) {
       for (AnalysisError error in errorInfo.errors) {
         if (computeSeverity(error) != null) {
           errors.add(error);
           errorToLine[error] = errorInfo.lineInfo;
         }
       }
     }
@@ skipping 49 matching lines @@
     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]);
 }