Remove dartc optimizing backend.

dart/compiler/java/com/google/dart/compiler/backend/js/ClosureJsBackend.java

Index: dart/compiler/java/com/google/dart/compiler/backend/js/ClosureJsBackend.java
diff --git a/dart/compiler/java/com/google/dart/compiler/backend/js/ClosureJsBackend.java b/dart/compiler/java/com/google/dart/compiler/backend/js/ClosureJsBackend.java
deleted file mode 100644
index c72c7f991872fbb21e179881667ee1cdefbb15c1..0000000000000000000000000000000000000000
--- a/dart/compiler/java/com/google/dart/compiler/backend/js/ClosureJsBackend.java
+++ /dev/null
@@ -1,664 +0,0 @@
-// Copyright (c) 2011, 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.
-
-package com.google.dart.compiler.backend.js;
-
-import com.google.common.base.Preconditions;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
-import com.google.common.io.CharStreams;
-import com.google.common.io.Closeables;
-import com.google.common.io.LimitInputStream;
-import com.google.dart.compiler.DartCompilationError;
-import com.google.dart.compiler.DartCompilerContext;
-import com.google.dart.compiler.DartSource;
-import com.google.dart.compiler.LibrarySource;
-import com.google.dart.compiler.Source;
-import com.google.dart.compiler.ast.DartUnit;
-import com.google.dart.compiler.ast.LibraryNode;
-import com.google.dart.compiler.ast.LibraryUnit;
-import com.google.dart.compiler.backend.js.ast.JsProgram;
-import com.google.dart.compiler.common.SourceInfo;
-import com.google.dart.compiler.metrics.CompilerMetrics;
-import com.google.dart.compiler.resolver.CoreTypeProvider;
-import com.google.javascript.jscomp.CheckLevel;
-import com.google.javascript.jscomp.CompilationLevel;
-import com.google.javascript.jscomp.Compiler;
-import com.google.javascript.jscomp.CompilerInput;
-import com.google.javascript.jscomp.CompilerOptions;
-import com.google.javascript.jscomp.DiagnosticGroups;
-import com.google.javascript.jscomp.JSError;
-import com.google.javascript.jscomp.JSModule;
-import com.google.javascript.jscomp.JSSourceFile;
-import com.google.javascript.jscomp.PropertyRenamingPolicy;
-import com.google.javascript.jscomp.Result;
-import com.google.javascript.jscomp.SourceAst;
-import com.google.javascript.jscomp.SourceMap.DetailLevel;
-import com.google.javascript.jscomp.SourceMap.Format;
-import com.google.javascript.jscomp.VariableRenamingPolicy;
-import com.google.javascript.jscomp.WarningLevel;
-
-import java.io.BufferedInputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.Reader;
-import java.io.StringReader;
-import java.io.StringWriter;
-import java.io.Writer;
-import java.net.URI;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-import java.util.zip.ZipEntry;
-import java.util.zip.ZipInputStream;
-
-/**
- * A compiler backend that produces raw Javascript.
- * @author johnlenz@google.com (John Lenz)
- */
-public class ClosureJsBackend extends AbstractJsBackend {
-  private static final String EXTENSION_OPT_JS = "opt.js";
-  private static final String EXTENSION_OPT_JS_SRC_MAP = "opt.js.map";
-
-  // A map of possible input sources to use when building the optimized output.
-  private Map<String, DartUnit> dartSrcToUnitMap = Maps.newHashMap();
-  private long totalJsOutputCharCount;
-
-  // Generate "readable" output for debugging
-  private final boolean generateHumanReadableOutput;
-  // Generate "good" instead of "best" output.
-  private final boolean fastOutput;
-  // TODO(johnlenz): Currently we can only support incremential builds
-  // if we aren't building source maps.
-  private final boolean incremental;
-
-  // Validate the generated JavaScript
-  private final boolean validate;
-
-  // Whether the generated code is "checked".
-  private final boolean checkedMode;
-
-  public ClosureJsBackend() {
-    this(false, false);
-  }
-
-  /**
-   * @param generateHumanReadableOutput - generates human readable javascript output.
-   */
-  public ClosureJsBackend(boolean checkedMode, boolean generateHumanReadableOutput) {
-    // Current default settings
-    this(false, false, true, checkedMode, generateHumanReadableOutput);
-  }
-
-  public ClosureJsBackend(boolean fastOutput,
-                          boolean incremental,
-                          boolean validate,
-                          boolean checkedMode,
-                          boolean generateHumanReadableOutput) {
-    this.fastOutput = fastOutput;
-    // can't currently produce a valid source map incrementally
-    this.incremental = incremental;
-    this.validate = validate;
-    this.checkedMode = checkedMode;
-    this.generateHumanReadableOutput = generateHumanReadableOutput;
-  }
-
-  @Override
-  public boolean isOutOfDate(DartSource src, DartCompilerContext context) {
-    if (!incremental) {
-      return true;
-    } else {
-      return super.isOutOfDate(src, context);
-    }
-  }
-
-  @Override
-  public void compileUnit(DartUnit unit, DartSource src,
-      DartCompilerContext context, CoreTypeProvider typeProvider) throws IOException {
-    if (!incremental) {
-      dartSrcToUnitMap.put(src.getName(), unit);
-    } else {
-      super.compileUnit(unit, src, context, typeProvider);
-    }
-  }
-
-  private Map<String, CompilerInput> createClosureJsAst(Map<String,JsProgram> parts, Source source) {
-    String name = source.getName();
-    Preconditions.checkState(name != null && !name.isEmpty(), "A source name is required");
-
-    Map<String, CompilerInput> translatedParts = new HashMap<String, CompilerInput>();
-    for (Map.Entry<String,JsProgram> part : parts.entrySet()) {
-      String partName = part.getKey();
-      String inputName = name + ':' + partName;
-      SourceAst sourceAst = new ClosureJsAst(part.getValue(), inputName, source, validate);
-      CompilerInput input = new CompilerInput(sourceAst, false);
-      translatedParts.put(part.getKey(), input);
-    }
-    return translatedParts;
-  }
-
-  private class DepsWritingCallback implements DepsCallback {
-    private final DartCompilerContext context;
-    private final CoreTypeProvider typeProvider;
-    private final List<CompilerInput> inputs;
-    private final Map<String, Source> sourcesByName;
-    private final Map<DartUnit, Map<String, CompilerInput>> translatedUnits = Maps.newHashMap();
-
-    DepsWritingCallback(
-        DartCompilerContext context,
-        CoreTypeProvider typeProvider,
-        List<CompilerInput> inputs,
-        Map<String, Source> sourcesByName) {
-      this.context = context;
-      this.typeProvider = typeProvider;
-      this.inputs = inputs;
-      this.sourcesByName = sourcesByName;
-    }
-
-    @Override
-    public void visitNative(LibraryUnit libUnit, LibraryNode node)
-        throws IOException {
-      String name = node.getText();
-      DartSource nativeSrc = libUnit.getSource().getSourceFor(name);
-      StringWriter w = new StringWriter();
-      Reader r = nativeSrc.getSourceReader();
-      CharStreams.copy(r, w);
-      inputs.add(new CompilerInput(createSource(name, w), false));
-    }
-
-    @Override
-    public void visitPart(Part part) throws IOException {
-      DartSource src = part.unit.getSource();
-      if (!incremental) {
-        Map<String, CompilerInput> translatedParts = translatedUnits.get(part.unit);
-        if (translatedParts == null) {
-          assert !sourcesByName.containsKey(src.getName());
-          sourcesByName.put(src.getName(), src);
-          Preconditions.checkNotNull(part.unit, "src: " + src.getName());
-          translatedParts = translateUnit(part.unit, src, context, typeProvider);
-          Preconditions.checkState(!translatedUnits.containsKey(part.unit));
-          translatedUnits.put(part.unit, translatedParts);
-        }
-        inputs.add(translatedParts.get(part.part));
-        return;
-      }
-
-      Reader r = context.getArtifactReader(src, part.part, EXTENSION_JS);
-      if (r == null) {
-        return;
-      }
-      StringWriter w = new StringWriter();
-      CharStreams.copy(r, w);
-      String inputName = src.getName() + ':' + part.part;
-      inputs.add(new CompilerInput(createSource(inputName, w), false));
-    }
-
-    private JSSourceFile createSource(String name, Writer w) {
-      return JSSourceFile.fromCode(name, w.toString());
-    }
-  }
-
-  private void packageAppOptimized(LibrarySource app,
-                                   Collection<LibraryUnit> libraries,
-                                   DartCompilerContext context,
-                                   CoreTypeProvider typeProvider)
-      throws IOException {
-
-    List<CompilerInput> inputs = Lists.newLinkedList();
-    Map<String, Source> sourcesByName = Maps.newHashMap();
-    DepsWritingCallback callback = new DepsWritingCallback(
-        context, typeProvider, inputs, sourcesByName);
-    DependencyBuilder.build(context.getAppLibraryUnit(), callback);
-
-    // Lastly, add the entry point.
-    inputs.add(getCompilerInputForEntry(context));
-
-    // Currently, there is only a single module, add all the sources to it.
-    JSModule mainModule = new JSModule("main");
-    for (CompilerInput input : inputs) {
-      if (input != null) {
-        mainModule.add(input);
-      }
-    }
-
-    Writer out = context.getArtifactWriter(app, "", getAppExtension());
-    boolean failed = true;
-    try {
-      compileModule(app, context, mainModule, sourcesByName, out);
-      failed = false;
-    } finally {
-      Closeables.close(out, failed);
-    }
-  }
-
-  private Map<String, CompilerInput> translateUnit(
-      DartUnit unit, DartSource src, DartCompilerContext context, CoreTypeProvider typeProvider) {
-    Map<String, JsProgram> parts = translateToJS(unit, context, typeProvider);
-
-    // Translate the AST and cache it for later use.
-    return createClosureJsAst(parts, src);
-  }
-
-  private CompilerInput getCompilerInputForEntry(DartCompilerContext context)
-      throws IOException {
-    StringWriter entry = new StringWriter();
-    writeEntryPointCall(getMangledEntryPoint(context), entry);
-    return new CompilerInput(
-        JSSourceFile.fromCode("entry", entry.toString()), false);
-  }
-
-  class MockSource implements Source {
-    private String sourceName;
-
-    MockSource(String sourceName) {
-      this.sourceName = sourceName;
-    }
-
-    @Override
-    public boolean exists() {
-      return true;
-    }
-
-    @Override
-    public long getLastModified() {
-      return 0;
-    }
-
-    @Override
-    public String getName() {
-      return sourceName;
-    }
-
-    @Override
-    public Reader getSourceReader() {
-      return new StringReader("");
-    }
-
-    @Override
-    public URI getUri() {
-      return null;
-    }
-  }
-
-  // Stub source info object for reporting errors coming from the Closure Compiler
-  static class JSErrorSourceInfo implements SourceInfo {
-    final JSError error;
-    final Source source;
-
-    JSErrorSourceInfo(JSError error, Source source) {
-      this.error = error;
-      this.source = source;
-    }
-
-    @Override
-    public Source getSource() {
-      return source;
-    }
-
-    @Override
-    public int getSourceColumn() {
-      return error.getCharno();
-    }
-
-    @Override
-    public int getSourceLength() {
-      return -1;
-    }
-
-    @Override
-    public int getSourceLine() {
-      return error.lineNumber;
-    }
-
-    @Override
-    public int getSourceStart() {
-      return -1;
-    }
-  }
-
-  private void compileModule(
-      LibrarySource src, DartCompilerContext context,
-      JSModule module,
-      Map<String, Source> sourcesByName,
-      Writer out) throws IOException {
-    // Turn off Closure Compiler logging
-    CompilerOptions options = getClosureCompilerOptions(context);
-    Logger.getLogger("com.google.javascript.jscomp").setLevel(Level.OFF);
-
-    Compiler compiler = new Compiler();
-
-    List<JSSourceFile> externs = getDefaultExterns();
-    List<JSModule> modules = Lists.newLinkedList();
-    modules.add(module);
-    compiler.disableThreads();
-    Result result = compiler.compileModules(externs, modules, options);
-
-    if (processResults(src, context, compiler, result, module, out) != 0) {
-      for (JSError error : result.errors) {
-        // Use the real dart source object when we can.
-        Source source = sourcesByName.get(error.sourceName);
-        if (source == null) {
-          // This might be a compiler generate source, whatever it is
-          // report it.
-          source = new MockSource(error.sourceName);
-        }
-        System.err.println("error optimizing:" + error.toString());
-        DartCompilationError dartError =
-            new DartCompilationError(new JSErrorSourceInfo(error, source),
-                ClosureJsErrorCode.INTERNAL_ERROR,
-                error.description);
-        context.onError(dartError);
-      }
-    }
-
-    out.close();
-  }
-
-  /**
-   * Processes the results of the compile job, and returns an error code.
-   */
-  private int processResults(LibrarySource src, DartCompilerContext context, Compiler compiler,
-      Result result, JSModule module, Writer out)
-      throws IOException {
-    if (result.success) {
-      // TODO(johnlenz): Append directly to the writer.
-      String output = compiler.toSource(module);
-      out.append(output);
-      out.append('\n');
-
-      if (generateSourceMap(context)) {
-        Writer srcMapOut = context.getArtifactWriter(src, "", getSourceMapExtension());
-        boolean failed = true;
-        try {
-          compiler.getSourceMap().appendTo(srcMapOut, module.getName());
-          failed = false;
-        } finally {
-          Closeables.close(srcMapOut, failed);
-        }
-      }
-      totalJsOutputCharCount = output.length();
-    }
-
-    // return 0 if no errors, the error count otherwise
-    return Math.min(result.errors.length, 0x7f);
-  }
-
-  private CompilerOptions getClosureCompilerOptions(DartCompilerContext context) {
-    CompilerOptions options = new CompilerOptions();
-    options.setCodingConvention(new ClosureJsCodingConvention());
-
-    // Set the optimization passes that we want.
-    if (fastOutput) {
-      options.smartNameRemoval = true;
-      options.collapseProperties = true;
-      options.removeUnusedPrototypeProperties = true;
-      options.removeUnusedVars = true;
-      options.setRenamingPolicy(VariableRenamingPolicy.ALL, PropertyRenamingPolicy.ALL_UNQUOTED);
-      // On by default
-      options.setReplaceIdGenerators(false);
-   } else {
-      CompilationLevel.ADVANCED_OPTIMIZATIONS.setOptionsForCompilationLevel(options);
-      options.setAssumeStrictThis(true);
-      // TODO(johnlenz): try out experimential inlining
-      // options.setAssumeClosuresOnlyCaptureReferences(true);
-
-      // TODO(johnlenz): rewriteFunctionExpressions kills the Richards benchmark,
-      // it needs some better heuristics.
-      options.rewriteFunctionExpressions = false;
-
-      // AliasKeywords has a runtime performance hit, disable it.
-      options.aliasKeywords = false;
-
-      // slow for little value
-      options.setPropertyAffinity(false);
-
-      // TODO(johnlenz): These passes use SimpleDefinitionFinder or equivalent, and operate
-      // based on property name, not object type. DisambiguateProperties helps but is not
-      // a complete fix even with complete type information.
-      // See http://code.google.com/p/closure-compiler/issues/detail?id=437.
-      // We need to develop a plan for how to deal with them.
-
-      options.computeFunctionSideEffects = false;
-      options.devirtualizePrototypeMethods = true;
-      options.inlineGetters = true;
-
-      // TODO(johnlenz): Some DOM definitions look like unused prototype property
-      // definitions because they are only referenced using dynamically generated
-      // names.
-      options.removeUnusedPrototypePropertiesInExterns = false;
-    }
-
-    if (generateSourceMap(context)) {
-      options.sourceMapOutputPath = "placeholder"; // anything will do
-      options.sourceMapDetailLevel = DetailLevel.SYMBOLS;
-      options.sourceMapFormat = Format.V3;
-    }
-
-    // Turn off the default checks.
-
-    // Dart doesn't currently need the Closure Library checks
-    // or optimizations.
-    options.closurePass = false;
-
-    // Disable type warnings as we don't provide any type information.
-    options.setInferTypes(false);
-    options.checkTypes = false;
-    options.setWarningLevel(DiagnosticGroups.CHECK_TYPES, CheckLevel.OFF);
-
-    // Disable other checks, that don't make sense for generated code
-    options.setWarningLevel(DiagnosticGroups.GLOBAL_THIS, CheckLevel.OFF);
-    options.checkSuspiciousCode = false;
-    options.checkGlobalThisLevel = CheckLevel.OFF;
-    options.checkMissingReturn = CheckLevel.OFF;
-    options.checkGlobalNamesLevel = CheckLevel.OFF;
-    options.aggressiveVarCheck = CheckLevel.OFF;
-    options.setWarningLevel(DiagnosticGroups.DEPRECATED, CheckLevel.OFF);
-
-    // Optionally turn on the checks that are useful to Dart
-    if (validate) {
-      options.checkSymbols = true;
-      options.setWarningLevel(DiagnosticGroups.ES5_STRICT, CheckLevel.ERROR);
-      // options.setAggressiveVarCheck(CheckLevel.ERROR);
-    } else {
-      // A lot of warnings don't make sense for generated code, or require type
-      // information. Turn them all off by default and make the ones we care
-      // about errors.
-      WarningLevel.QUIET.setOptionsForWarningLevel(options);
-
-      options.checkSymbols = false;
-      options.setWarningLevel(DiagnosticGroups.ES5_STRICT, CheckLevel.OFF);
-    }
-
-    // To ease debugging, try enabling these options:
-    if (generateHumanReadableOutput) {
-      options.prettyPrint = true;
-      options.generatePseudoNames = true;
-      options.printInputDelimiter = true;
-      options.inputDelimiter = "// Input %name%";
-    }
-    // If those aren't enough, try disabling these:
-    // options.setRenamingPolicy(VariableRenamingPolicy.OFF, PropertyRenamingPolicy.OFF);
-    // options.coalesceVariableNames = false;
-    // options.setShadowVariables(false);
-    // options.inlineFunctions = false;
-
-    /*
-     * NOTE: We turn this off because TypeErrors or anything that relies on a type name will fail
-     * due to the class renaming.
-     */
-    if (checkedMode) {
-      options.setReplaceIdGenerators(false);
-    }
-
-    return options;
-  }
-
-  // The externs expected in externs.zip, in sorted order.
-  private static final List<String> DEFAULT_EXTERNS_NAMES = ImmutableList.of(
-    // JS externs
-    "es3.js",
-    "es5.js",
-    // "json.js", // TODO(johnlenz): add this.
-
-    // Event APIs
-    "w3c_event.js",
-    "w3c_event3.js",
-    "gecko_event.js",
-    "ie_event.js",
-    "webkit_event.js",
-
-    // DOM apis
-    "w3c_dom1.js",
-    "w3c_dom2.js",
-    "w3c_dom3.js",
-    "gecko_dom.js",
-    "ie_dom.js",
-    "webkit_dom.js",
-
-    // CSS apis
-    "w3c_css.js",
-    "gecko_css.js",
-    "ie_css.js",
-    "webkit_css.js",
-
-    // Top-level namespaces
-    "google.js",
-
-    "deprecated.js",
-    "fileapi.js",
-    "flash.js",
-    "gears_symbols.js",
-    "gears_types.js",
-    "gecko_xml.js",
-    "html5.js",
-    "ie_vml.js",
-    "iphone.js",
-    "webstorage.js",
-    "w3c_anim_timing.js",
-    "w3c_css3d.js",
-    "w3c_elementtraversal.js",
-    "w3c_geolocation.js",
-    "w3c_indexeddb.js",
-    "w3c_navigation_timing.js",
-    "w3c_range.js",
-    "w3c_selectors.js",
-    "w3c_xml.js",
-    "window.js",
-    "webkit_notifications.js",
-    "webgl.js");
-
-  // Add a declarations for the V8 logging function.
-  private static final String UNIT_TEST_EXTERN_STUBS = "var write;";
-
-  private static final String CLOSURE_PRIMITIVES = "function JSCompiler_renameProperty() {};";
-
-  // TODO(johnlenz): include json.js in the default set of externs.
-  private static final String MISSING_EXTERNS =
-      "var JSON = {};\n" +
-      "/**\n" +
-      " * @param {string} jsonStr The string to parse.\n" +
-      " * @param {(function(string, *) : *)=} opt_reviver\n" +
-      " * @return {*} The JSON object.\n" +
-      " */\n" +
-      "JSON.parse = function(jsonStr, opt_reviver) {};\n" +
-      "\n" +
-      "/**\n" +
-      " * @param {*} jsonObj Input object.\n" +
-      " * @param {(Array.<string>|(function(string, *) : *)|null)=} opt_replacer\n" +
-      " * @param {(number|string)=} opt_space\n" +
-      " * @return {string} json string which represents jsonObj.\n" +
-      " */\n" +
-      "JSON.stringify = function(jsonObj, opt_replacer, opt_space) {};" +
-      "\n";
-
-  /**
-   * @return a mutable list
-   * @throws IOException
-   */
-  private static List<JSSourceFile> getDefaultExterns() throws IOException {
-    Class<ClosureJsBackend> clazz = ClosureJsBackend.class;
-    InputStream input = clazz.getResourceAsStream(
-        "/com/google/javascript/jscomp/externs.zip");
-    if (input == null) {
-      /*
-       * HACK - the open source version of the closure compiler maps the
-       * resource into a different location.
-       */
-      input = clazz.getResourceAsStream("/externs.zip");
-    }
-    ZipInputStream zip = new ZipInputStream(input);
-    Map<String, JSSourceFile> externsMap = Maps.newHashMap();
-    for (ZipEntry entry = null; (entry = zip.getNextEntry()) != null; ) {
-      InputStream entryStream = new BufferedInputStream(
-          new LimitInputStream(zip, entry.getSize()));
-      externsMap.put(entry.getName(),
-          JSSourceFile.fromInputStream(
-              // Give the files an odd prefix, so that they do not conflict
-              // with the user's files.
-              "externs.zip//" + entry.getName(),
-              entryStream));
-    }
-
-    Preconditions.checkState(
-        externsMap.keySet().equals(Sets.newHashSet(DEFAULT_EXTERNS_NAMES)),
-        "Externs zip must match our hard-coded list of externs.");
-
-    // Order matters, so the resources must be added to the result list
-    // in the expected order.
-    List<JSSourceFile> externs = Lists.newArrayList();
-    for (String key : DEFAULT_EXTERNS_NAMES) {
-      externs.add(externsMap.get(key));
-    }
-
-    // Add methods used when running the unit tests.
-    externs.add(JSSourceFile.fromCode("missingExterns", MISSING_EXTERNS));
-
-    // Add methods used when running the unit tests.
-    externs.add(JSSourceFile.fromCode("unitTestStubs", UNIT_TEST_EXTERN_STUBS));
-
-    // Add methods used by Closure Compiler itself.
-    externs.add(JSSourceFile.fromCode("closureCompilerPrimitives", CLOSURE_PRIMITIVES));
-
-    return externs;
-  }
-
-  @Override
-  public void packageApp(LibrarySource app,
-                         Collection<LibraryUnit> libraries,
-                         DartCompilerContext context,
-                         CoreTypeProvider typeProvider)
-      throws IOException {
-    totalJsOutputCharCount = 0;
-    packageAppOptimized(app, libraries, context, typeProvider);
-    CompilerMetrics compilerMetrics = context.getCompilerMetrics();
-    if (compilerMetrics != null) {
-      compilerMetrics.packagedJsApplication(totalJsOutputCharCount, -1);
-    }
-  }
-
-  @Override
-  public String getAppExtension() {
-    return (incremental) ? EXTENSION_APP_JS : EXTENSION_OPT_JS;
-  }
-
-  @Override
-  public String getSourceMapExtension() {
-    return (incremental) ? EXTENSION_APP_JS_SRC_MAP : EXTENSION_OPT_JS_SRC_MAP;
-  }
-
-  @Override
-  protected boolean shouldOptimize() {
-    return (fastOutput) ? false : true;
-  }
-
-  @Override
-  protected boolean generateClosureCompatibleCode() {
-    return true;
-  }
-}