Remove backends.

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

Index: compiler/java/com/google/dart/compiler/backend/js/ScopeRootInfo.java
diff --git a/compiler/java/com/google/dart/compiler/backend/js/ScopeRootInfo.java b/compiler/java/com/google/dart/compiler/backend/js/ScopeRootInfo.java
deleted file mode 100644
index e3681b92d540b50513067c69378db45c054a20cd..0000000000000000000000000000000000000000
--- a/compiler/java/com/google/dart/compiler/backend/js/ScopeRootInfo.java
+++ /dev/null
@@ -1,533 +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.collect.Lists;
-import com.google.common.collect.Maps;
-import com.google.common.collect.Sets;
-import com.google.dart.compiler.ast.DartBlock;
-import com.google.dart.compiler.ast.DartCatchBlock;
-import com.google.dart.compiler.ast.DartClass;
-import com.google.dart.compiler.ast.DartClassMember;
-import com.google.dart.compiler.ast.DartContext;
-import com.google.dart.compiler.ast.DartExpression;
-import com.google.dart.compiler.ast.DartField;
-import com.google.dart.compiler.ast.DartForInStatement;
-import com.google.dart.compiler.ast.DartForStatement;
-import com.google.dart.compiler.ast.DartFunction;
-import com.google.dart.compiler.ast.DartFunctionExpression;
-import com.google.dart.compiler.ast.DartFunctionObjectInvocation;
-import com.google.dart.compiler.ast.DartIdentifier;
-import com.google.dart.compiler.ast.DartInitializer;
-import com.google.dart.compiler.ast.DartMethodDefinition;
-import com.google.dart.compiler.ast.DartNode;
-import com.google.dart.compiler.ast.DartParameter;
-import com.google.dart.compiler.ast.DartThisExpression;
-import com.google.dart.compiler.ast.DartTypeParameter;
-import com.google.dart.compiler.ast.DartUnit;
-import com.google.dart.compiler.ast.DartVariable;
-import com.google.dart.compiler.backend.js.ast.JsName;
-import com.google.dart.compiler.backend.js.ast.JsScope;
-import com.google.dart.compiler.common.Symbol;
-import com.google.dart.compiler.resolver.Element;
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.Deque;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-/**
- * Information relating to a methods scope, symbols, and closures
- */
-class ScopeRootInfo {
-  /**
-   * Defines a relationship between a DartSymbol and a scope.
-   */
-  static class DartScope {
-    /**
-     * A simple class for storing information about a symbol, specifically
-     * whether the symbol is referenced by a closure.
-     */
-    static class DartSymbolInfo {
-      private final DartScope owningScope;
-      private boolean referencedFromClosure = false;
-
-      public DartSymbolInfo(DartScope owningScope) {
-        this.owningScope = owningScope;
-      }
-
-      public DartScope getOwningScope() {
-        return owningScope;
-      }
-
-      public boolean isReferencedFromClosure() {
-        return referencedFromClosure;
-      }
-
-      public void setReferencedFromClosure(boolean referencedFromClosure) {
-        this.referencedFromClosure = referencedFromClosure;
-      }
-    }
-
-    private final DartScope parent;
-    private Map<Symbol, DartScope.DartSymbolInfo> symbols = Maps.newLinkedHashMap();
-    private Map<JsScope, JsName> jsAliasNames = Maps.newHashMap();
-    // The scope's depth from the initial method definition scope.
-    private final int depth;
-
-    public DartScope(DartScope parent) {
-      this.parent = parent;
-      this.depth = (parent != null) ? parent.getDepth() + 1 : 0;
-    }
-
-    public void declare(Symbol symbol) {
-      symbols.put(symbol, new DartSymbolInfo(this));
-    }
-
-    public int getDepth() {
-      return depth;
-    }
-
-    public DartScope getParent() {
-      return parent;
-    }
-
-    public DartScope findSymbolScope(Symbol symbol) {
-      DartScope current = this;
-      while (current != null) {
-        DartScope.DartSymbolInfo info = current.getSymbolInfo(symbol);
-        if (info != null) {
-          return current;
-        }
-        current = current.getParent();
-      }
-      return null;
-    }
-
-    public DartScope.DartSymbolInfo getSymbolInfo(Symbol symbol) {
-      return this.symbols.get(symbol);
-    }
-    
-    public Map<Symbol, DartScope.DartSymbolInfo> getSymbols() {
-      return symbols;
-    }
-
-    public boolean definesClosureReferencedSymbols() {
-      for (DartScope.DartSymbolInfo symbol : symbols.values()) {
-        if (symbol.isReferencedFromClosure()) {
-          return true;
-        }
-      }
-      return false;
-    }
-
-    private String getScopeAliasName() {
-      return "dartc_scp$" + depth;
-    }
-
-    /**
-     * Returns the alias-object-JsName of this DartScope in the given JsScope. If none exists yet,
-     * creates a new one.
-     *
-     * @param jsScope
-     * @return the JsName representing the alias object for this DartScope.
-     */
-    public JsName getAliasForJsScope(JsScope jsScope) {
-      JsName result = findAliasForJsScope(jsScope);
-      if (result == null) {
-        result = jsScope.declareFreshName(getScopeAliasName());
-        jsAliasNames.put(jsScope, result);
-      }
-      return result;
-    }
-
-    /**
-     * Returns the alias-object-JsName of this DartScope in the given JsScope. If none exists yet,
-     * null is returned.
-     *
-     * @param jsScope
-     * @return the JsName representing the alias object for this DartScope.
-     */
-    public JsName findAliasForJsScope(JsScope jsScope) {
-      return jsAliasNames.get(jsScope);
-    }
-  }
-  
-  /**
-   * A simple class to keep track of the scope referenced by a closure,
-   * also whether the closure references "this".
-   */
-  public static class ClosureInfo {
-    final Set<DartScope> referencedScopes = Sets.newHashSet();
-
-    boolean referencesThis = false;
-
-    public List<DartScope> getSortedReferencedScopeList() {
-      ArrayList<DartScope> sortedScopes = Lists.newArrayList(
-          referencedScopes);
-      Collections.sort(sortedScopes, new Comparator<DartScope>(){
-        @Override
-        public int compare(DartScope s1, DartScope s2) {
-          return s1.getDepth() - s2.getDepth();
-        }});
-      return sortedScopes;
-    }
-  }
-
-  /**
-   * A generic helper class for visiting DartScope definitions.
-   */
-  static private abstract class DartScopesVisitor extends NormalizedVisitor {
-
-    // A place to store the constructor initializer list to the initializers
-    // can be visited within the scope of the constructor's parameters.
-    private List<DartInitializer> pendingConstructorInitList = null;
-
-    @Override
-    public boolean visit(DartUnit x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartClass x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartMethodDefinition x, DartContext ctx) {
-      this.pendingConstructorInitList = x.getInitializers();
-      accept(x.getFunction());
-      return false;
-    }
-
-    @Override
-    public void endVisit(DartMethodDefinition x, DartContext ctx) {
-      assert this.pendingConstructorInitList == null;
-    }
-
-    @Override
-    public boolean visit(DartFunctionExpression x, DartContext ctx) {
-      // For function statements, the function's name belong in the outer scope.
-      // For function expressions, it is part of the function's own scope.
-      if (!x.isStatement()) {
-        return enterScope(x, ctx);
-      }
-      return true;
-    }
-
-    @Override
-    public boolean visit(DartFunction x, DartContext ctx) {
-      boolean enter = enterScope(x, ctx);
-      if (enter) {
-        // Save and clear the cached init lists before processing
-        // any function as default parameters or in init list.
-        List<DartInitializer> inits = pendingConstructorInitList;
-        pendingConstructorInitList = null;
-        acceptList(x.getParams());
-        if (inits != null) {
-          acceptList(inits);
-        }
-        if (x.getBody() != null) {
-          accept(x.getBody());
-        }
-      }
-      return false;
-    }
-
-    @Override
-    public boolean visit(DartBlock x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartCatchBlock x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartForInStatement x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartForStatement x, DartContext ctx) {
-      return enterScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartUnit x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartClass x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartFunctionExpression x, DartContext ctx) {
-      if (!x.isStatement()) {
-        exitScope(x, ctx);
-      }
-    }
-
-    @Override
-    public void endVisit(DartFunction x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartBlock x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartCatchBlock x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartForStatement x, DartContext ctx) {
-      exitScope(x, ctx);
-    }
-
-    abstract boolean enterScope(DartNode x, DartContext ctx);
-    abstract void exitScope(DartNode x, DartContext ctx);
-  }
-
-  /**
-   * Build a set of ClosureInfo objects for the method,
-   * find and mark any variable referenced by a closure.
-   */
-  private static class ClosureRefenceMapBuilder extends ScopeRootInfo.DartScopesVisitor {
-    private final Map<DartNode, DartScope> scopes;
-    private Deque<DartScope> scopeStack = Lists.newLinkedList();
-    private final Map<DartFunction, ScopeRootInfo.ClosureInfo> closures = Maps.newHashMap();
-    private Deque<DartFunction> closureStack = Lists.newLinkedList();
-    private final boolean respectInlinableModifier;
-    
-    ClosureRefenceMapBuilder(Map<DartNode, DartScope> scopes, boolean respectInlinableModifier) {
-      this.scopes = scopes;
-      this.respectInlinableModifier = respectInlinableModifier;
-    }
-
-    @Override
-    boolean enterScope(DartNode x, DartContext ctx) {
-      scopeStack.push(scopes.get(x));
-      return true;
-    }
-
-    @Override
-    void exitScope(DartNode x, DartContext ctx) {
-      scopeStack.pop();
-    }
-
-    @Override
-    public boolean visit(DartFunctionObjectInvocation x, DartContext ctx) {
-      DartExpression target = x.getTarget();
-      if (target instanceof DartFunctionExpression) {
-        DartFunctionExpression functionExpression = (DartFunctionExpression) target;
-        if (respectInlinableModifier && 
-            functionExpression.getSymbol().getModifiers().isInlinable()) {
-          acceptList(x.getArgs());
-          return traverseFunction(functionExpression.getFunction(), ctx);
-        }
-      }
-      return super.visit(x, ctx);
-    }
-
-    // Inlined from DartFunction#traverse(DartVisitor, DartContext).
-    private boolean traverseFunction(DartFunction function, DartContext ctx) {
-      for (DartParameter parameter : function.getParams()) {
-        doTraverse(parameter, ctx);
-      }
-      if (function.getBody() != null) {
-        doTraverse(function.getBody(), ctx);
-      }
-      // Ignore the return type.
-      return false;
-    }
-
-    @Override
-    public boolean visit(DartFunction x, DartContext ctx) {
-      this.closures.put(x, new ClosureInfo());
-      this.closureStack.push(x);
-      return super.visit(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartFunction x, DartContext ctx) {
-      closureStack.pop();
-      super.endVisit(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartIdentifier x, DartContext ctx) {
-      processSymbol(x.getTargetSymbol());
-      super.endVisit(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartThisExpression x, DartContext ctx) {
-      for (DartFunction closure : closureStack) {
-        ScopeRootInfo.ClosureInfo info = closures.get(closure);
-        info.referencesThis = true;
-      }
-    }
-
-    private void processSymbol(Symbol targetSymbol) {
-      if (targetSymbol != null) {
-        DartNode node = targetSymbol.getNode();
-        if (node instanceof DartClassMember<?>) {
-          // Special case: implicit instance/static member references.
-          DartClassMember<?> member = (DartClassMember<?>) node;
-          if (!member.getModifiers().isStatic()) {
-            // A member reference implies a reference to the current "this"
-            // object, the closure will need to pass it through.
-            for (DartFunction closure : closureStack) {
-              ScopeRootInfo.ClosureInfo info = closures.get(closure);
-              info.referencesThis = true;
-            }
-          }
-        }
-
-        if (closureStack.size() > 0) {
-          DartScope currentScope = this.scopeStack.peek();
-          DartScope symbolScope = currentScope.findSymbolScope(targetSymbol);
-          if (symbolScope != null) {
-            boolean referencedFromClosure = false;
-            for (DartFunction closure : closureStack) {
-              DartScope closureScope = scopes.get(closure);
-              // For each of the closures, determine if the value is defined
-              // outside outside the current closure, if so record its use.
-              if (symbolScope.getDepth() < closureScope.getDepth()) {
-                ScopeRootInfo.ClosureInfo info = closures.get(closure);
-                info.referencedScopes.add(symbolScope);
-                referencedFromClosure = true;
-              }
-            }
-            if (referencedFromClosure) {
-              symbolScope.getSymbolInfo(targetSymbol)
-                  .setReferencedFromClosure(true);
-            }
-          }
-        }
-      }
-    }
-  }
-
-  /**
-   * Build the DartScope objects for a method.
-   */
-  static private class MethodScopeMapBuilder extends ScopeRootInfo.DartScopesVisitor {
-    private Map<DartNode, DartScope> scopes = Maps.newLinkedHashMap();
-    private Deque<DartScope> scopeStack = Lists.newLinkedList();
-
-    @Override
-    boolean enterScope(DartNode x, DartContext ctx) {
-      scopeStack.push(new DartScope(scopeStack.peek()));
-      scopes.put(x, scopeStack.peek());
-      return true;
-    }
-
-    @Override
-    void exitScope(DartNode x, DartContext ctx) {
-      scopeStack.pop();
-    }
-
-    // TODO(johnlenz): Handle catch exception declarations.
-
-    @Override
-    public void endVisit(DartParameter x, DartContext ctx) {
-      DartScope currentScope = scopeStack.peek();
-      currentScope.declare(x.getSymbol());
-      super.endVisit(x, ctx);
-    }
-
-    @Override
-    public void endVisit(DartVariable x, DartContext ctx) {
-      DartScope currentScope = scopeStack.peek();
-      currentScope.declare(x.getSymbol());
-      super.endVisit(x, ctx);
-    }
-
-    @Override
-    public boolean visit(DartFunctionExpression x, DartContext ctx) {
-      DartScope currentScope = scopeStack.peek();
-      boolean visit = super.visit(x, ctx);
-      if (!x.isStatement()) {
-        // Declare the symbol in the new scope
-        currentScope = scopeStack.peek();
-      }
-      currentScope.declare(x.getSymbol());
-      return visit;
-    }
-  }
-
-  private final DartClassMember<?> classMember;
-  private final Map<Symbol, DartScope.DartSymbolInfo> symbols = Maps.newHashMap();
-  private final Map<DartFunction, ScopeRootInfo.ClosureInfo> closures;
-  private final Map<DartNode, DartScope> scopes;
-  private int closureIds = 0;
-
-  static ScopeRootInfo makeScopeInfo(DartMethodDefinition x, boolean respectInlinableModifier) {
-    return makeScopeInfoImpl(x, respectInlinableModifier);
-  }
-
-  static ScopeRootInfo makeScopeInfo(DartField x, boolean respectInlinableModifier) {
-    return makeScopeInfoImpl(x, respectInlinableModifier);
-  }
-
-  private static ScopeRootInfo makeScopeInfoImpl(DartClassMember<?> x, 
-      boolean respectInlinableModifier) {
-    ScopeRootInfo.MethodScopeMapBuilder scopeBuilder = new MethodScopeMapBuilder();
-    scopeBuilder.accept(x);
-    ScopeRootInfo.ClosureRefenceMapBuilder closureBuilder = new ClosureRefenceMapBuilder(
-        scopeBuilder.scopes, respectInlinableModifier);
-    closureBuilder.accept(x);
-    return new ScopeRootInfo(x, scopeBuilder.scopes, closureBuilder.closures);
-  }
-
-  ScopeRootInfo(
-      DartClassMember<?> x, Map<DartNode, DartScope> scopes,
-      Map<DartFunction, ScopeRootInfo.ClosureInfo> closures) {
-    this.classMember = x;
-    this.closures = closures;
-    this.scopes = scopes;
-    for (DartScope scope : scopes.values()) {
-      this.symbols.putAll(scope.getSymbols());
-    }
-  }
-
-  Element getContainingElement() {
-    return classMember.getSymbol();
-  }
-
-  DartClassMember<?> getContainingClassMember() {
-    return classMember;
-  }
-
-  DartScope.DartSymbolInfo getSymbolInfo(Symbol targetSymbol) {
-    return symbols.get(targetSymbol);
-  }
-
-  public ScopeRootInfo.ClosureInfo getClosureInfo(DartFunction x) {
-    return closures.get(x);
-  }
-
-  public DartScope getScope(DartNode x) {
-    return scopes.get(x);
-  }
-
-  /**
-   * @return A name for a closure unique within this method.
-   */
-  public String getNextClosureName() {
-    return "c" + closureIds++;
-  }
-}