Custom formatter cleanup Fix case where displaying a class constructor generated unreadable huge ou…

pkg/dev_compiler/lib/src/compiler/code_generator.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.
 
 import 'dart:collection' show HashMap, HashSet;
 import 'dart:math' show min, max;
 
 import 'package:analyzer/analyzer.dart' hide ConstantEvaluator;
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 173 matching lines @@
   /// Takes the metadata for the build unit, as well as resolved trees and
   /// errors, and computes the output module code and optionally the source map.
   JSModuleFile compile(BuildUnit unit, List<CompilationUnit> compilationUnits,
       List<String> errors) {
     _buildUnit = unit;
     _libraryRoot = _buildUnit.libraryRoot;
     if (!_libraryRoot.endsWith(separator)) {
       _libraryRoot += separator;
     }
 
-    var module = _emitModule(compilationUnits);
+    var module = _emitModule(compilationUnits, unit.name);
     var dartApiSummary = _summarizeModule(compilationUnits);
 
     return new JSModuleFile(unit.name, errors, options, module, dartApiSummary);
   }
 
   List<int> _summarizeModule(List<CompilationUnit> units) {
     if (!options.summarizeApi) return null;
 
     if (!units.any((u) => resolutionMap
         .elementDeclaredByCompilationUnit(u)
@@ skipping 25 matching lines @@
             context.declaredVariables.get,
             true)
         .forEach(assembler.addLinkedLibrary);
 
     var bundle = assembler.assemble();
     // Preserve only API-level information in the summary.
     bundle.flushInformative();
     return bundle.toBuffer();
   }
 
-  JS.Program _emitModule(List<CompilationUnit> compilationUnits) {
+  JS.Program _emitModule(List<CompilationUnit> compilationUnits, String name) {
     if (_moduleItems.isNotEmpty) {
       throw new StateError('Can only call emitModule once.');
     }
 
     // Transform the AST to make coercions explicit.
     compilationUnits = CoercionReifier.reify(compilationUnits);
 
     if (compilationUnits.any((u) => _isDartRuntime(
         resolutionMap.elementDeclaredByCompilationUnit(u).library))) {
       // Don't allow these to be renamed when we're building the SDK.
@@ skipping 62 matching lines @@
     // This is done by forward declaring items.
     compilationUnits.forEach(_finishDeclarationsInUnit);
 
     // Declare imports
     _finishImports(items);
 
     // Discharge the type table cache variables and
     // hoisted definitions.
     items.addAll(_typeTable.discharge());
 
+    // Track the module name for each library in the module.
+    // This data is only required for debugging.
+    _moduleItems.add(js.statement('#.trackLibraries(#, #);',
+        [_runtimeModule, js.string(name), _librariesDebuggerObject()]));
+
     // Add the module's code (produced by visiting compilation units, above)
     _copyAndFlattenBlocks(items, _moduleItems);
 
     // Build the module.
     return new JS.Program(items, name: _buildUnit.name);
   }
 
+  JS.ObjectInitializer _librariesDebuggerObject() {
+    var properties = <JS.Property>[];
+    _libraries.forEach((library, value) {
+      // TODO(jacobr): we could specify a short library name instead of the
+      // full library uri if we wanted to save space.
+      properties.add(new JS.Property(
+          js.string(jsLibraryDebuggerName(_libraryRoot, library)), value));
+    });
+    return new JS.ObjectInitializer(properties);
+  }
+
   List<String> _getJSName(Element e) {
     if (e.library == null ||
         findAnnotation(e.library, isPublicJSAnnotation) == null) {
       return null;
     }
 
     var libraryJSName = getAnnotationName(e.library, isPublicJSAnnotation);
     var libraryPrefix = <String>[];
     if (libraryJSName != null && libraryJSName.isNotEmpty) {
       libraryPrefix.addAll(libraryJSName.split('.'));
@@ skipping 110 matching lines @@
       //
       //     import {foo} from 'foo';         // if no rename needed
       //     import {foo as foo$} from 'foo'; // if rename was needed
       //
       var imports =
           libraries.map((l) => new JS.NameSpecifier(_imports[l])).toList();
       if (module == coreModuleName) {
         imports.add(new JS.NameSpecifier(_runtimeModule));
         imports.add(new JS.NameSpecifier(_extensionSymbolsModule));
       }
+
       items.add(new JS.ImportDeclaration(
           namedImports: imports, from: js.string(module, "'")));
     });
   }
 
   /// Collect toplevel elements and nodes we need to emit, and returns
   /// an ordered map of these.
   static void _collectElements(
       CompilationUnit unit, Map<Element, AstNode> map) {
     for (var declaration in unit.declarations) {
@@ skipping 5376 matching lines @@
     qualifiedPath =
         uri.path.substring(libraryRoot.length).replaceAll('/', separator);
   } else {
     // We don't have a unique name.
     throw 'Invalid library root. $libraryRoot does not contain ${uri
         .toFilePath()}';
   }
   return pathToJSIdentifier(qualifiedPath);
 }
 
+/// Debugger friendly name for a Dart Library.
+String jsLibraryDebuggerName(String libraryRoot, LibraryElement library) {
+  var uri = library.source.uri;
+  // For package: and dart: uris show the entire
+  if (uri.scheme == 'dart' || uri.scheme == 'package') return uri.toString();
+
+  if (!uri.toFilePath().startsWith(libraryRoot)) {
+    throw 'Invalid library root. $libraryRoot does not contain ${uri
+        .toFilePath()}';
+  }
+  // Relative path to the library.
+  return uri.path.substring(libraryRoot.length);
+}
+
+String jsDebuggingLibraryName(String libraryRoot, LibraryElement library) {
+  var uri = library.source.uri;
+  if (uri.scheme == 'dart') {
+    return uri.path;
+  }
+  // TODO(vsm): This is not necessarily unique if '__' appears in a file name.
+  var separator = '__';
+  String qualifiedPath;
+  if (uri.scheme == 'package') {
+    // Strip the package name.
+    // TODO(vsm): This is not unique if an escaped '/'appears in a filename.
+    // E.g., "foo/bar.dart" and "foo$47bar.dart" would collide.
+    qualifiedPath = uri.pathSegments.skip(1).join(separator);
+  } else if (uri.toFilePath().startsWith(libraryRoot)) {
+    qualifiedPath =
+        uri.path.substring(libraryRoot.length).replaceAll('/', separator);
+  } else {
+    // We don't have a unique name.
+    throw 'Invalid library root. $libraryRoot does not contain ${uri
+        .toFilePath()}';
+  }
+  return pathToJSIdentifier(qualifiedPath);
+}
+
 /// Shorthand for identifier-like property names.
 /// For now, we emit them as strings and the printer restores them to
 /// identifiers if it can.
 // TODO(jmesserly): avoid the round tripping through quoted form.
 JS.LiteralString _propertyName(String name) => js.string(name, "'");
 
 // TODO(jacobr): we would like to do something like the following
 // but we don't have summary support yet.
 // bool _supportJsExtensionMethod(AnnotatedNode node) =>
 //    _getAnnotation(node, "SupportJsExtensionMethod") != null;
@@ skipping 35 matching lines @@
   if (targetIdentifier.staticElement is! PrefixElement) return false;
   var prefix = targetIdentifier.staticElement as PrefixElement;
 
   // The library the prefix is referring to must come from a deferred import.
   var containingLibrary = resolutionMap
       .elementDeclaredByCompilationUnit(target.root as CompilationUnit)
       .library;
   var imports = containingLibrary.getImportsWithPrefix(prefix);
   return imports.length == 1 && imports[0].isDeferred;
 }