Implement modular compilation

lib/src/compiler/error_helpers.dart

-// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// 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, StaticWarningCode;
+import 'package:analyzer/source/error_processor.dart' show ErrorProcessor;
 import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
-import 'package:analyzer/src/generated/error.dart';
-import 'package:logging/logging.dart';
 import 'package:path/path.dart' as path;
-import 'package:analyzer/source/error_processor.dart';
 
-final _checkerLogger = new Logger('dev_compiler.checker');
+// 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) {
+  errors.sort((AnalysisError error1, AnalysisError error2) {
+    // severity
+    var severity1 = errorSeverity(context, error1);
+    var severity2 = errorSeverity(context, error2);
+    int compare = severity2.compareTo(severity1);
+    if (compare != 0) return compare;
 
-/// Collects errors, and then sorts them and sends them
-class ErrorCollector implements AnalysisErrorListener {
-  final AnalysisContext _context;
-  final AnalysisErrorListener listener;
-  final List<AnalysisError> _errors = [];
+    // path
+    compare = Comparable.compare(error1.source.fullName.toLowerCase(),
+        error2.source.fullName.toLowerCase());
+    if (compare != 0) return compare;
 
-  ErrorCollector(this._context, this.listener);
+    // offset
+    compare = error1.offset - error2.offset;
+    if (compare != 0) return compare;
 
-  /// Flushes errors to the log. Until this is called, errors are buffered.
-  void flush() {
-    // TODO(jmesserly): this code was taken from analyzer_cli.
-    // sort errors
-    _errors.sort((AnalysisError error1, AnalysisError error2) {
-      // severity
-      var severity1 = errorSeverity(_context, error1);
-      var severity2 = errorSeverity(_context, error2);
-      int compare = severity2.compareTo(severity1);
-      if (compare != 0) return compare;
+    // compare message, in worst case.
+    return error1.message.compareTo(error2.message);
+  });
+}
 
-      // path
-      compare = Comparable.compare(error1.source.fullName.toLowerCase(),
-          error2.source.fullName.toLowerCase());
-      if (compare != 0) return compare;
+// TODO(jmesserly): this was from analyzer_cli, we should factor it differently.
+String formatError(AnalysisContext context, AnalysisError error) {
+  var severity = errorSeverity(context, error);
+  // Skip hints, some like TODOs are not useful.
+  if (severity.ordinal <= ErrorSeverity.INFO.ordinal) return null;
 
-      // offset
-      compare = error1.offset - error2.offset;
-      if (compare != 0) return compare;
+  var lineInfo = context.computeLineInfo(error.source);
+  var location = lineInfo.getLocation(error.offset);
 
-      // compare message, in worst case.
-      return error1.message.compareTo(error2.message);
-    });
-
-    _errors.forEach(listener.onError);
-    _errors.clear();
-  }
-
-  void onError(AnalysisError error) {
-    _errors.add(error);
-  }
+  // [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) {
   var code = error.errorCode;
   if (code is StaticWarningCode) {
     // TODO(jmesserly): many more warnings need to be promoted for soundness.
     // Also code generation will blow up finding null types/elements for many
     // of these, or we rely on them to produce valid optimizations.
     switch (code.name) {
       case 'AMBIGUOUS_IMPORT':
@@ skipping 111 matching lines @@
   // 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, error)?.severity ??
       error.errorCode.errorSeverity;
 }
-
-/// Simple reporter that logs checker messages as they are seen.
-class LogReporter implements AnalysisErrorListener {
-  final AnalysisContext _context;
-  final bool useColors;
-  final List<AnalysisError> _errors = [];
-
-  LogReporter(this._context, {this.useColors: false});
-
-  void onError(AnalysisError error) {
-    var level = _severityToLevel[errorSeverity(_context, error)];
-
-    // TODO(jmesserly): figure out what to do with the error's name.
-    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)
-    var text = new StringBuffer()
-      ..write('[${error.errorCode.name}] ')
-      ..write(error.message)
-      ..write(' (${path.prettyUri(error.source.uri)}')
-      ..write(', line ${location.lineNumber}, col ${location.columnNumber})');
-
-    // TODO(jmesserly): just print these instead of sending through logger?
-    _checkerLogger.log(level, text);
-  }
-}
-
-// TODO(jmesserly): remove log levels, instead just use severity.
-const _severityToLevel = const {
-  ErrorSeverity.ERROR: Level.SEVERE,
-  ErrorSeverity.WARNING: Level.WARNING,
-  ErrorSeverity.INFO: Level.INFO
-};