Remove backends.

compiler/java/com/google/dart/compiler/backend/js/ast/JsScope.java

Index: compiler/java/com/google/dart/compiler/backend/js/ast/JsScope.java
diff --git a/compiler/java/com/google/dart/compiler/backend/js/ast/JsScope.java b/compiler/java/com/google/dart/compiler/backend/js/ast/JsScope.java
deleted file mode 100644
index 0344842aa6140dcad04ae08a13b0fdaf445a1369..0000000000000000000000000000000000000000
--- a/compiler/java/com/google/dart/compiler/backend/js/ast/JsScope.java
+++ /dev/null
@@ -1,301 +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.ast;
-
-import com.google.common.collect.Interner;
-import com.google.common.collect.Interners;
-import com.google.dart.compiler.util.Lists;
-import com.google.dart.compiler.util.Maps;
-
-import java.io.Serializable;
-import java.util.Collections;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
-
-/**
- * A scope is a factory for creating and allocating
- * {@link com.google.dart.compiler.backend.js.ast.JsName}s. A JavaScript AST is
- * built in terms of abstract name objects without worrying about obfuscation,
- * keyword/identifier blacklisting, and so on.
- *
- * <p>
- *
- * Scopes are associated with
- * {@link com.google.dart.compiler.backend.js.ast.JsFunction}s, but the two are
- * not equivalent. Functions <i>have</i> scopes, but a scope does not
- * necessarily have an associated Function. Examples of this include the
- * {@link com.google.dart.compiler.backend.js.ast.JsRootScope} and synthetic
- * scopes that might be created by a client.
- *
- * <p>
- *
- * Scopes can have parents to provide constraints when allocating actual
- * identifiers for names. Specifically, names in child scopes are chosen such
- * that they do not conflict with names in their parent scopes. The ultimate
- * parent is usually the global scope (see
- * {@link com.google.dart.compiler.backend.js.ast.JsProgram#getRootScope()}),
- * but parentless scopes are useful for managing names that are always accessed
- * with a qualifier and could therefore never be confused with the global scope
- * hierarchy.
- */
-public class JsScope implements Serializable {
-
-  private List<JsScope> children = Collections.emptyList();
-  private final String description;
-  private Map<String, JsName> names = Collections.emptyMap();
-  private JsScope parent;
-  protected int tempIndex = 0;
-  private final String scopeId;
-  private static Interner<String> interner = Interners.newWeakInterner();
-
- /*
-  * Create a scope with parent.
-  */
- public JsScope(JsScope parent, String description) {
-   this(parent, description, null);
- }
-
-  /**
-   * Create a scope with parent.
-   */
-  public JsScope(JsScope parent, String description, String scopeId) {
-    assert (parent != null);
-    this.scopeId = scopeId;
-    this.description = interner.intern(description);
-    this.parent = parent;
-    parent.children = Lists.add(parent.children, this);
-  }
-
-  /**
-   * Rebase the function to a new scope.
-   * @param newParent The scope to add the function to.
-   */
-  public void rebase(JsScope newParent) {
-    detachFromParent();
-    parent = newParent;
-    parent.children = Lists.add(parent.children, this);
-  }
-
-  /**
-   * Rebase the function's children to a new scope.
-   * @param newParent
-   */
-  public void rebaseChildScopes(JsScope newParent) {
-    if (newParent == this) {
-      return;
-    }
-    parent.children = Lists.addAll(parent.children, children);
-    for (JsScope child : children) {
-      child.parent = newParent;
-    }
-    children = Collections.emptyList();
-  }
-
-  /**
-   * Subclasses can detach and become parentless.
-   */
-  protected void detachFromParent() {
-    JsScope oldParent = parent;
-
-    oldParent.children = Lists.remove(
-        parent.children, oldParent.children.indexOf(this));
-
-    parent = null;
-  }
-
-  /**
-   * Subclasses can be parentless.
-   */
-  protected JsScope(String description) {
-    this.description = description;
-    this.parent = null;
-    this.scopeId = null;
-  }
-
-  /**
-   * Gets a name object associated with the specified ident in this scope,
-   * creating it if necessary.<br/>
-   * If the JsName does not exist yet, a new JsName is created. The ident,
-   * short name, and original name of the newly created JsName are equal to
-   * the given ident.
-   *
-   * @param ident An identifier that is unique within this scope.
-   */
-  public JsName declareName(String ident) {
-    JsName name = findExistingNameNoRecurse(ident);
-    if (name != null) {
-      return name;
-    }
-    return doCreateName(ident, ident, ident);
-  }
-
-  /**
-   * Creates a new variable with an unique ident in this scope.
-   * The generated JsName is guaranteed to have an identifier (but not short
-   * name) that does not clash with any existing variables in the scope.
-   * Future declarations of variables might however clash with the temporary
-   * (unless they use this function).
-   */
-  public JsName declareFreshName(String shortName) {
-    String ident = shortName;
-    int counter = 0;
-    while (findExistingNameNoRecurse(ident) != null) {
-      ident = shortName + "_" + counter++;
-    }
-    return doCreateName(ident, shortName, shortName);
-  }
-
-  String getNextTempName() {
-    // TODO(ngeoffray): Decide on a convention for temporary variables
-    // introduced by the compiler.
-    return "tmp$" + (scopeId != null ? scopeId + "$" : "") + tempIndex++;
-  }
-
-  /**
-   * Creates a temporary variable with an unique name in this scope.
-   * The generated temporary is guaranteed to have an identifier (but not short
-   * name) that does not clash with any existing variables in the scope.
-   * Future declarations of variables might however clash with the temporary.
-   */
-  public JsName declareTemporary() {
-    return declareFreshName(getNextTempName());
-  }
-
-  /**
-   * Gets a name object associated with the specified ident in this scope,
-   * creating it if necessary.<br/>
-   * If the JsName does not exist yet, a new JsName is created with the given
-   * ident, short name and original name.
-   *
-   * @param ident An identifier that is unique within this scope.
-   * @param shortIdent A "pretty" name that does not have to be unique.
-   * @throws IllegalArgumentException if ident already exists in this scope but
-   *           the requested short name does not match the existing short name.
-   */
-  public JsName declareName(String ident, String shortIdent) {
-    return declareName(ident, shortIdent, ident);
-  }
-
-  /**
-   * Gets a name object associated with the specified ident in this scope,
-   * creating it if necessary.<br/>
-   * If the JsName does not exist yet, a new JsName is created. The original
-   * name stored in the JsName is equal to the (unmangled) specified originalName.
-   *
-   * @param ident An identifier that is unique within this scope.
-   * @param shortIdent A "pretty" name that does not have to be unique.
-   * @param originalName The original name in the source.
-   * @throws IllegalArgumentException if ident already exists in this scope but
-   *           the requested short name does not match the existing short name,
-   *           or the original name does not match the existing original name.
-   */
-  public JsName declareName(String ident, String shortIdent, String originalName) {
-    JsName name = findExistingNameNoRecurse(ident);
-    if (name != null) {
-      if (!name.getShortIdent().equals(shortIdent)
-          || !nullableEquals(name.getOriginalName(), originalName)) {
-        throw new IllegalArgumentException("Requested short name " + shortIdent
-            + " conflicts with preexisting short name " + name.getShortIdent() + " for identifier "
-            + ident);
-      }
-      return name;
-    }
-    return doCreateName(ident, shortIdent, originalName);
-  }
-
-  boolean nullableEquals(String s1, String s2) {
-    return (s1 == null) ? (s2 == null) : s1.equals(s2);
-  }
-
-  /**
-   * Attempts to find the name object for the specified ident, searching in this
-   * scope, and if not found, in the parent scopes.
-   *
-   * @return <code>null</code> if the identifier has no associated name
-   */
-  public final JsName findExistingName(String ident) {
-    JsName name = findExistingNameNoRecurse(ident);
-    if (name == null && parent != null) {
-      return parent.findExistingName(ident);
-    }
-    return name;
-  }
-
-  /**
-   * Attempts to find an unobfuscatable name object for the specified ident,
-   * searching in this scope, and if not found, in the parent scopes.
-   *
-   * @return <code>null</code> if the identifier has no associated name
-   */
-  public final JsName findExistingUnobfuscatableName(String ident) {
-    JsName name = findExistingNameNoRecurse(ident);
-    if (name != null && name.isObfuscatable()) {
-      name = null;
-    }
-    if (name == null && parent != null) {
-      return parent.findExistingUnobfuscatableName(ident);
-    }
-    return name;
-  }
-
-  /**
-   * Returns an iterator for all the names defined by this scope.
-   */
-  public Iterator<JsName> getAllNames() {
-    return names.values().iterator();
-  }
-
-  /**
-   * Returns a list of this scope's child scopes.
-   */
-  public final List<JsScope> getChildren() {
-    return children;
-  }
-
-  /**
-   * Returns the parent scope of this scope, or <code>null</code> if this is the
-   * root scope.
-   */
-  public final JsScope getParent() {
-    return parent;
-  }
-
-  /**
-   * Returns the associated program.
-   */
-  public JsProgram getProgram() {
-    assert (parent != null) : "Subclasses must override getProgram() if they do not set a parent";
-    return parent.getProgram();
-  }
-
-  @Override
-  public final String toString() {
-    if (parent != null) {
-      return description + "->" + parent;
-    } else {
-      return description;
-    }
-  }
-
-  /**
-   * Creates a new name in this scope.
-   */
-  protected JsName doCreateName(String ident, String shortIdent, String originalName) {
-    JsName name = new JsName(this, ident, shortIdent, originalName);
-    names = Maps.putOrdered(names, ident, name);
-    return name;
-  }
-
-  /**
-   * Attempts to find the name object for the specified ident, searching in this
-   * scope only.
-   *
-   * @return <code>null</code> if the identifier has no associated name
-   */
-  protected JsName findExistingNameNoRecurse(String ident) {
-    return names.get(ident);
-  }
-}