Migrate DDC to the new analysis driver.

pkg/dev_compiler/lib/src/compiler/error_helpers.dart

 // Copyright (c) 2016, 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.
 
 import 'package:analyzer/analyzer.dart' show AnalysisError, ErrorSeverity;
 import 'package:analyzer/source/error_processor.dart' show ErrorProcessor;
-import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
+import 'package:analyzer/src/generated/engine.dart' show AnalysisOptions;
+import 'package:analyzer/src/generated/source.dart';
 import 'package:path/path.dart' as path;
 
-// TODO(jmesserly): this code was taken from analyzer_cli.
-// It really should be in some common place so we can share it.
-// TODO(jmesserly): this shouldn't depend on `context` but we need it to compute
-// `errorSeverity` due to some APIs that need fixing.
-void sortErrors(AnalysisContext context, List<AnalysisError> errors) {
+/// TODO(jmesserly): this code was taken from analyzer_cli.
+/// It really should be in some common place so we can share it.
+/// TODO(jmesserly): this shouldn't depend on `context` but we need it to compute
+/// `errorSeverity` due to some APIs that need fixing.
+void sortErrors(AnalysisOptions analysisOptions, List<AnalysisError> errors) {
   errors.sort((AnalysisError error1, AnalysisError error2) {
     // severity
-    var severity1 = errorSeverity(context, error1);
-    var severity2 = errorSeverity(context, error2);
+    var severity1 = errorSeverity(analysisOptions, error1);
+    var severity2 = errorSeverity(analysisOptions, error2);
     int compare = severity2.compareTo(severity1);
     if (compare != 0) return compare;
 
     // path
     compare = Comparable.compare(error1.source.fullName.toLowerCase(),
         error2.source.fullName.toLowerCase());
     if (compare != 0) return compare;
 
     // offset
     compare = error1.offset - error2.offset;
     if (compare != 0) return compare;
 
     // compare message, in worst case.
     return error1.message.compareTo(error2.message);
   });
 }
 
-// TODO(jmesserly): this was from analyzer_cli, we should factor it differently.
-String formatError(AnalysisContext context, AnalysisError error) {
-  var severity = errorSeverity(context, error);
+/// TODO(jmesserly): this was from analyzer_cli, we should factor it differently.
+String formatError(
+    AnalysisOptions analysisOptions, LineInfo lineInfo, AnalysisError error) {
+  var severity = errorSeverity(analysisOptions, error);
   // Skip hints, some like TODOs are not useful.
   if (severity.ordinal <= ErrorSeverity.INFO.ordinal) return null;
 
-  var lineInfo = context.computeLineInfo(error.source);
   var location = lineInfo.getLocation(error.offset);
 
   // [warning] 'foo' is not a... (/Users/.../tmp/foo.dart, line 1, col 2)
   return (new StringBuffer()
         ..write('[${severity.displayName}] ')
         ..write(error.message)
         ..write(' (${path.prettyUri(error.source.uri)}')
         ..write(', line ${location.lineNumber}, col ${location.columnNumber})'))
       .toString();
 }
 
-ErrorSeverity errorSeverity(AnalysisContext context, AnalysisError error) {
+ErrorSeverity errorSeverity(
+    AnalysisOptions analysisOptions, AnalysisError error) {
   // TODO(jmesserly): this Analyzer API totally bonkers, but it's what
   // analyzer_cli and server use.
   //
   // Among the issues with ErrorProcessor.getProcessor:
   // * it needs to be called per-error, so it's a performance trap.
   // * it can return null
   // * using AnalysisError directly is now suspect, it's a correctness trap
-  // * it requires an AnalysisContext
-  return ErrorProcessor
-          .getProcessor(context.analysisOptions, error)
-          ?.severity ??
+  return ErrorProcessor.getProcessor(analysisOptions, error)?.severity ??
       error.errorCode.errorSeverity;
 }