Refactor location computation in dart2js mirrors.

sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart

Index: sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
diff --git a/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart b/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
index 0962c2de7729639f83dfc6b95d3ec3883624e948..7e7e4823367cf371c83a62f6c71971203534cd3f 100644
--- a/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
+++ b/sdk/lib/_internal/compiler/implementation/mirrors/dart2js_mirror.dart
@@ -433,12 +433,40 @@ abstract class Dart2JsMirror implements Mirror {
   Dart2JsMirrorSystem get mirrors;
 }
 
-abstract class Dart2JsDeclarationMirror
-    implements Dart2JsMirror, DeclarationMirror {
+abstract class Dart2JsDeclarationMirror extends Dart2JsMirror
+    implements DeclarationMirror {
 
   bool get isTopLevel => owner != null && owner is LibraryMirror;
 
   bool get isPrivate => _isPrivate(simpleName);
+
+  /**
+   * Returns the first token for the source of this declaration.
+   */
+  Token getBeginToken();
+
+  /**
+   * Returns the last token for the source of this declaration.
+   */
+  Token getEndToken();
+
+  /**
+   * Returns the script for the source of this declaration.
+   */
+  Script getScript();
+
+  SourceLocation get location {
+    Token beginToken = getBeginToken();
+    Script script = getScript();
+    SourceSpan span;
+    if (beginToken == null) {
+      span = new SourceSpan(script.uri, 0, 0);
+    } else {
+      Token endToken = getEndToken();
+      span = mirrors.compiler.spanFromTokens(beginToken, endToken, script.uri);
+    }
+    return new Dart2JsSourceLocation(script, span);
+  }
 }
 
 abstract class Dart2JsMemberMirror extends Dart2JsElementMirror
@@ -477,9 +505,30 @@ abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
 
   String get displayName => simpleName;
 
-  SourceLocation get location => new Dart2JsSourceLocation(
-      _element.getCompilationUnit().script,
-      mirrors.compiler.spanFromElement(_element));
+  Token getBeginToken() {
+    if (!_element.metadata.isEmpty) {
+      for (MetadataAnnotation metadata in _element.metadata) {
+        if (metadata.beginToken != null) {
+          return metadata.beginToken;
+        }
+      }
+    }
+    Node node = _element.parseNode(mirrors.compiler);

[ahe, 2013/01/03 18:58:21]

This is brittle as it can cause a parse error.  Ideally, you'd be able to
extract a span directly from the element.  For example, PartialClassElement has
two fields, beginToken and endToken.

The "original" partial elements (PartialFunctionElement and PartialClassElement
both record both begin and end tokens.  Partial elements that have been added
later do not (PartialTypedefElement and PartialMetadataAnnotation).  However, it
should be easy to fix that.

[Johnni Winther, 2013/01/04 09:57:55]

Added a TODO.

+    if (node == null) {
+      return _element.position();
+    }
+    return node.getBeginToken();
+  }
+
+  Token getEndToken() {
+    Node node = _element.parseNode(mirrors.compiler);
+    if (node == null) {
+      return _element.position();
+    }
+    return node.getBeginToken();
+  }
+
+  Script getScript() => _element.getCompilationUnit().script;
 
   String toString() => _element.toString();
 
@@ -499,21 +548,11 @@ abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
   }
 }
 
-abstract class Dart2JsProxyMirror extends Dart2JsDeclarationMirror {
-  final Dart2JsMirrorSystem mirrors;
-
-  Dart2JsProxyMirror(this.mirrors);
-
-  String get displayName => simpleName;
-
-  int get hashCode => qualifiedName.hashCode;
-}
-
 //------------------------------------------------------------------------------
 // Mirror system implementation.
 //------------------------------------------------------------------------------
 
-class Dart2JsMirrorSystem implements MirrorSystem, Dart2JsMirror {
+class Dart2JsMirrorSystem implements MirrorSystem {
   final api.Compiler compiler;
   Map<String, Dart2JsLibraryMirror> _libraries;
   Map<LibraryElement, Dart2JsLibraryMirror> _libraryMap;
@@ -679,15 +718,20 @@ class Dart2JsLibraryMirror extends Dart2JsContainerMirror
     return new ImmutableMapWrapper<String, ClassMirror>(_classes);
   }
 
-  SourceLocation get location {
-    var script = _library.getCompilationUnit().script;
-    SourceSpan span;
+  Token getBeginToken() {

[ahe, 2013/01/03 18:58:21]

Document what you do here.

[Johnni Winther, 2013/01/04 09:57:55]

Done.

     if (_library.libraryTag != null) {
-      span = mirrors.compiler.spanFromNode(_library.libraryTag, script.uri);
-    } else {
-      span = new SourceSpan(script.uri, 0, 0);
+      return _library.libraryTag.getBeginToken();
+    } else if (!_library.tags.isEmpty) {
+      return _library.tags.reverse().head.getBeginToken();
     }
-    return new Dart2JsSourceLocation(script, span);
+    return null;
+  }
+
+  Token getEndToken() {
+    if (!_library.tags.isEmpty) {
+      return _library.tags.head.getEndToken();
+    }
+    return null;
   }
 }
 
@@ -869,18 +913,6 @@ class Dart2JsClassMirror extends Dart2JsContainerMirror
 
   String get qualifiedName => '${library.qualifiedName}.${simpleName}';
 
-  SourceLocation get location {
-    if (_class is PartialClassElement) {
-      var node = _class.parseNode(mirrors.compiler);
-      if (node != null) {
-        var script = _class.getCompilationUnit().script;
-        var span = mirrors.compiler.spanFromNode(node, script.uri);
-        return new Dart2JsSourceLocation(script, span);
-      }
-    }
-    return super.location;
-  }
-
   void _ensureMembers() {
     if (_members == null) {
       _members = <String, Dart2JsMemberMirror>{};
@@ -1005,16 +1037,6 @@ class Dart2JsTypedefMirror extends Dart2JsTypeElementMirror
 
   String get qualifiedName => '${library.qualifiedName}.${simpleName}';
 
-  SourceLocation get location {
-    var node = _typedef.element.parseNode(_diagnosticListener);
-    if (node != null) {
-      var script = _typedef.element.getCompilationUnit().script;
-      var span = mirrors.compiler.spanFromNode(node, script.uri);
-      return new Dart2JsSourceLocation(script, span);
-    }
-    return super.location;
-  }
-
   LibraryMirror get library => _library;
 
   bool get isTypedef => true;
@@ -1123,22 +1145,16 @@ class Dart2JsTypeVariableMirror extends Dart2JsTypeElementMirror
 // Types
 //------------------------------------------------------------------------------
 
-abstract class Dart2JsTypeElementMirror extends Dart2JsProxyMirror
+abstract class Dart2JsTypeElementMirror extends Dart2JsElementMirror
     implements Dart2JsTypeMirror {
   final DartType _type;
-  List<InstanceMirror> _metadata;
 
-  Dart2JsTypeElementMirror(Dart2JsMirrorSystem system, this._type)
-    : super(system);
+  Dart2JsTypeElementMirror(Dart2JsMirrorSystem system, DartType type)
+    : super(system, type.element),
+      this._type = type;
 
   String get simpleName => _type.name.slowToString();
 
-  SourceLocation get location {
-    var script = _type.element.getCompilationUnit().script;
-    return new Dart2JsSourceLocation(script,
-        mirrors.compiler.spanFromElement(_type.element));
-  }
-
   DeclarationMirror get owner => library;
 
   LibraryMirror get library {
@@ -1157,7 +1173,7 @@ abstract class Dart2JsTypeElementMirror extends Dart2JsProxyMirror
 
   bool get isFunction => false;
 
-  String toString() => _type.element.toString();
+  String toString() => _type.toString();
 
   Map<String, MemberMirror> get members => const <String, MemberMirror>{};
 
@@ -1172,20 +1188,6 @@ abstract class Dart2JsTypeElementMirror extends Dart2JsProxyMirror
   Map<String, VariableMirror> get variables => const <String, VariableMirror>{};
 
   ClassMirror get defaultFactory => null;
-
-  // TODO(johnniwinther): Should a type show the metadata of its declaration?
-  List<InstanceMirror> get metadata {
-    if (_metadata == null) {
-      var _metadata = <InstanceMirror>[];
-      for (MetadataAnnotation metadata in _type.element.metadata) {
-        metadata.ensureResolved(mirrors.compiler);
-        _metadata.add(
-            _convertConstantToInstanceMirror(mirrors, metadata.value));
-      }
-    }
-    // TODO(johnniwinther): Return an unmodifiable list instead.
-    return new List<InstanceMirror>.from(_metadata);
-  }
 }
 
 class Dart2JsInterfaceTypeMirror extends Dart2JsTypeElementMirror
@@ -1566,17 +1568,6 @@ class Dart2JsMethodMirror extends Dart2JsMemberMirror
   bool get isSetter => _kind == Dart2JsMethodKind.SETTER;
 
   bool get isOperator => _kind == Dart2JsMethodKind.OPERATOR;
-
-  SourceLocation get location {
-    var node = _function.parseNode(_diagnosticListener);
-    if (node != null) {
-      var script = _function.getCompilationUnit().script;
-      var span = mirrors.compiler.spanFromNode(node, script.uri);
-      return new Dart2JsSourceLocation(script, span);
-    }
-    return super.location;
-  }
-
 }
 
 class Dart2JsFieldMirror extends Dart2JsMemberMirror implements VariableMirror {
@@ -1607,18 +1598,6 @@ class Dart2JsFieldMirror extends Dart2JsMemberMirror implements VariableMirror {
   TypeMirror get type => _convertTypeToTypeMirror(mirrors,
       _variable.computeType(mirrors.compiler),
       mirrors.compiler.types.dynamicType);
-
-  SourceLocation get location {
-    var script = _variable.getCompilationUnit().script;
-    var node = _variable.variables.parseNode(_diagnosticListener);
-    if (node != null) {
-      var span = mirrors.compiler.spanFromNode(node, script.uri);
-      return new Dart2JsSourceLocation(script, span);
-    } else {
-      var span = mirrors.compiler.spanFromElement(_variable);
-      return new Dart2JsSourceLocation(script, span);
-    }
-  }
 }
 
 ////////////////////////////////////////////////////////////////////////////////