import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
CollectDefines(AbstractCompiler compiler, List<Name> listOfDefines) {
  this.compiler = compiler;
  this.allDefines = Maps.newHashMap();

  assignableDefines = Maps.newHashMap();
  assignAllowed = new ArrayDeque<Integer>();
  assignAllowed.push(1);

  // Create a map of references to defines keyed by node for easy lookup
  allRefInfo = Maps.newHashMap();
  for (Name name : listOfDefines) {
    if (name.declaration != null) {
      allRefInfo.put(name.declaration.node,
                     new RefInfo(name.declaration, name));
    }
    if (name.refs != null) {
      for (Ref ref : name.refs) {
        // If there's a TWIN def, only put one of the twins in.
        if (ref.getTwin() == null || !ref.getTwin().isSet()) {
          allRefInfo.put(ref.node, new RefInfo(ref, name));
        }
      }
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Runs through all namespaces (prefixes of classes and enums), and checks if
 * any of them have been used in an unsafe way.
 */
private void checkNamespaces() {
  for (Name name : nameMap.values()) {
    if (name.isNamespace() && name.refs != null &&
        (name.aliasingGets > 0 || name.localSets + name.globalSets > 1)) {
      boolean initialized = name.declaration != null;
      for (Ref ref : name.refs) {
        if (ref.type == Ref.Type.SET_FROM_GLOBAL ||
            ref.type == Ref.Type.SET_FROM_LOCAL) {
          if (initialized) {
            warnAboutNamespaceRedefinition(name, ref);
          }

          initialized = true;
        } else if (ref.type == Ref.Type.ALIASING_GET) {
          warnAboutNamespaceAliasing(name, ref);
        }
      }
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
private void validateName(Name name, boolean isDefined) {
  // If the name is not defined, emit warnings for each reference. While
  // we're looking through each reference, check all the module dependencies.
  Ref declaration = name.declaration;
  if (!isDefined) {
    if (declaration != null) {
      reportRefToUndefinedName(name, declaration);
    }
  }

  if (name.refs != null) {
    JSModuleGraph moduleGraph = compiler.getModuleGraph();
    for (Ref ref : name.refs) {
      if (!isDefined) {
        reportRefToUndefinedName(name, ref);
      } else {
        if (declaration != null &&
            ref.module != declaration.module &&
            !moduleGraph.dependsOn(ref.module, declaration.module)) {
          reportBadModuleReference(name, ref);
        }
      }
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration1() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.declaration);
  assertEquals(2, n.globalSets);
  assertEquals(1, n.refs.size());

  n.removeRef(set1);

  assertEquals(set2, n.declaration);
  assertEquals(1, n.globalSets);
  assertEquals(0, n.refs.size());
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration2() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_LOCAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.declaration);
  assertEquals(1, n.globalSets);
  assertEquals(1, n.localSets);
  assertEquals(1, n.refs.size());

  n.removeRef(set1);

  assertEquals(null, n.declaration);
  assertEquals(0, n.globalSets);
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration1() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.getDeclaration());
  assertEquals(2, n.globalSets);
  assertEquals(2, n.getRefs().size());

  n.removeRef(set1);

  assertEquals(set2, n.getDeclaration());
  assertEquals(1, n.globalSets);
  assertEquals(1, n.getRefs().size());
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration2() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_LOCAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.getDeclaration());
  assertEquals(1, n.globalSets);
  assertEquals(1, n.localSets);
  assertEquals(2, n.getRefs().size());

  n.removeRef(set1);

  assertEquals(null, n.getDeclaration());
  assertEquals(0, n.globalSets);
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Returns true if the alias is possibly defined in the global scope, which we handle with more
 * caution than with locally scoped variables. May return false positives.
 *
 * @param alias An aliasing get.
 * @return If the alias is possibly defined in the global scope.
 */
private boolean mayBeGlobalAlias(Ref alias) {
  // Note: alias.scope is the closest scope in which the aliasing assignment occurred.
  // So for "if (true) { var alias = aliasedVar; }", the alias.scope would be the IF block scope.
  if (alias.scope.isGlobal()) {
    return true;
  }
  // If the scope in which the alias is assigned is not global, look up the LHS of the assignment.
  Node aliasParent = alias.node.getParent();
  if (!aliasParent.isAssign() && !aliasParent.isName()) {
    // Only handle variable assignments and initializing declarations.
    return true;
  }
  Node aliasLhsNode = aliasParent.isName() ? aliasParent : aliasParent.getFirstChild();
  if (!aliasLhsNode.isName()) {
    // Only handle assignments to simple names, not qualified names or GETPROPs.
    return true;
  }
  String aliasVarName = aliasLhsNode.getString();
  Var aliasVar = alias.scope.getVar(aliasVarName);
  if (aliasVar != null) {
    return aliasVar.isGlobal();
  }
  return true;
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration1() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.getDeclaration());
  assertEquals(2, n.globalSets);
  assertThat(n.getRefs()).hasSize(2);

  n.removeRef(set1);

  assertEquals(set2, n.getDeclaration());
  assertEquals(1, n.globalSets);
  assertThat(n.getRefs()).hasSize(1);
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
public void testRemoveDeclaration2() {
  Name n = new Name("a", null, false);
  Ref set1 = createNodelessRef(Ref.Type.SET_FROM_GLOBAL);
  Ref set2 = createNodelessRef(Ref.Type.SET_FROM_LOCAL);

  n.addRef(set1);
  n.addRef(set2);

  assertEquals(set1, n.getDeclaration());
  assertEquals(1, n.globalSets);
  assertEquals(1, n.localSets);
  assertThat(n.getRefs()).hasSize(2);

  n.removeRef(set1);

  assertNull(n.getDeclaration());
  assertEquals(0, n.globalSets);
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Finds all defines, and creates a {@link DefineInfo} data structure for
 * each one.
 * @return A map of {@link DefineInfo} structures, keyed by name.
 */
private Map<String, DefineInfo> collectDefines(Node root,
    GlobalNamespace namespace) {
  // Find all the global names with a @define annotation
  List<Name> allDefines = Lists.newArrayList();
  for (Name name : namespace.getNameIndex().values()) {
    if (name.docInfo != null && name.docInfo.isDefine()) {
      allDefines.add(name);
    } else if (name.refs != null) {
      for (Ref ref : name.refs) {
        Node n = ref.node;
        Node parent = ref.node.getParent();
        JSDocInfo info = n.getJSDocInfo();
        if (info == null &&
            parent.getType() == Token.VAR && parent.hasOneChild()) {
          info = parent.getJSDocInfo();
        }

        if (info != null && info.isDefine()) {
          allDefines.add(name);
          break;
        }
      }
    }
  }

  CollectDefines pass = new CollectDefines(compiler, allDefines);
  NodeTraversal.traverse(compiler, root, pass);
  return pass.getAllDefines();
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Gets the parent node of the value for any assignment to a Name.
 * For example, in the assignment
 * {@code var x = 3;}
 * the parent would be the NAME node.
 */
private static Node getValueParent(Ref ref) {
  // there are two types of declarations: VARs and ASSIGNs
  return ref.node.getParent() != null &&
      ref.node.getParent().getType() == Token.VAR ?
      ref.node : ref.node.getParent();
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * For each qualified name N in the global scope, we check if:
 * (a) No ancestor of N is ever aliased or assigned an unknown value type.
 *     (If N = "a.b.c", "a" and "a.b" are never aliased).
 * (b) N has exactly one write, and it lives in the global scope.
 * (c) N is aliased in a local scope.
 *
 * If (a) is true, then GlobalNamespace must know all the writes to N.
 * If (a) and (b) are true, then N cannot change during the execution of
 *    a local scope.
 * If (a) and (b) and (c) are true, then the alias can be inlined if the
 *    alias obeys the usual rules for how we decide whether a variable is
 *    inlineable.
 * @see InlineVariables
 */
private void inlineAliases(GlobalNamespace namespace) {
  // Invariant: All the names in the worklist meet condition (a).
  Deque<Name> workList = new ArrayDeque<Name>(namespace.getNameForest());
  while (!workList.isEmpty()) {
    Name name = workList.pop();

    if (name.globalSets == 1 && name.localSets == 0 &&
        name.aliasingGets > 0) {
      // {@code name} meets condition (b). Find all of its local aliases
      // and try to inline them.
      List<Ref> refs = Lists.newArrayList(name.refs);
      for (Ref ref : refs) {
        if (ref.type == Type.ALIASING_GET && ref.scope.isLocal()) {
          // {@code name} meets condition (c). Try to inline it.
          if (inlineAliasIfPossible(ref, namespace)) {
            name.removeRef(ref);
          }
        }
      }
    }

    // Check if {@code name} has any aliases left after the
    // local-alias-inlining above.
    if ((name.type == Name.Type.OBJECTLIT ||
         name.type == Name.Type.FUNCTION) &&
        name.aliasingGets == 0 && name.props != null) {
      // All of {@code name}'s children meet condition (a), so they can be
      // added to the worklist.
      workList.addAll(name.props);
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Flattens all references to a collapsible property of a global name except
 * its initial definition.
 *
 * @param n A global property name (e.g. "a.b" or "a.b.c.d")
 * @param alias The flattened name (e.g. "a$b" or "a$b$c$d")
 */
private void flattenReferencesTo(Name n, String alias) {
  if (n.refs != null) {
    String originalName = n.fullName();
    for (Ref r : n.refs) {
      Node rParent = r.node.getParent();

      // There are two cases when we shouldn't flatten a reference:
      // 1) Object literal keys, because duplicate keys show up as refs.
      // 2) References inside a complex assign. (a = x.y = 0). These are
      //    called TWIN references, because they show up twice in the
      //    reference list. Only collapse the set, not the alias.
      if (!NodeUtil.isObjectLitKey(r.node, rParent) &&
          (r.getTwin() == null || r.isSet())) {
        flattenNameRef(alias, r.node, rParent, originalName);
      }
    }
  }

  // Flatten all occurrences of a name as a prefix of its subnames. For
  // example, if {@code n} corresponds to the name "a.b", then "a.b" will be
  // replaced with "a$b" in all occurrences of "a.b.c", "a.b.c.d", etc.
  if (n.props != null) {
    for (Name p : n.props) {
      flattenPrefixes(alias, p, 1);
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Flattens all occurrences of a name as a prefix of subnames beginning
 * with a particular subname.
 *
 * @param n A global property name (e.g. "a.b.c.d")
 * @param alias A flattened prefix name (e.g. "a$b")
 * @param depth The difference in depth between the property name and
 *    the prefix name (e.g. 2)
 */
private void flattenPrefixes(String alias, Name n, int depth) {
  // Only flatten the prefix of a name declaration if the name being
  // initialized is fully qualified (i.e. not an object literal key).
  String originalName = n.fullName();
  if (n.declaration != null && n.declaration.node != null &&
      n.declaration.node.getType() == Token.GETPROP) {
    flattenNameRefAtDepth(alias, n.declaration.node, depth, originalName);
  }

  if (n.refs != null) {
    for (Ref r : n.refs) {

      // References inside a complex assign (a = x.y = 0)
      // have twins. We should only flatten one of the twins.
      if (r.getTwin() == null || r.isSet()) {
        flattenNameRefAtDepth(alias, r.node, depth, originalName);
      }
    }
  }

  if (n.props != null) {
    for (Name p : n.props) {
      flattenPrefixes(alias, p, depth + 1);
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Updates the first initialization (a.k.a "declaration") of a global name
 * that occurs at a VAR node. See comment for
 * {@link #updateObjLitOrFunctionDeclaration}.
 *
 * @param n An object representing a global name (e.g. "a")
 */
private void updateObjLitOrFunctionDeclarationAtVarNode(Name n) {
  Ref ref = n.declaration;
  String name = ref.node.getString();
  Node rvalue = ref.node.getFirstChild();
  Node varNode = ref.node.getParent();
  Node gramps = varNode.getParent();

  boolean isObjLit = rvalue.getType() == Token.OBJECTLIT;
  int numChanges = 0;

  if (isObjLit) {
    boolean discardKeys = n.aliasingGets == 0;
    numChanges += declareVarsForObjLitValues(
        n, name, rvalue, varNode, gramps.getChildBefore(varNode),
        gramps, discardKeys);
  }

  numChanges += addStubsForUndeclaredProperties(n, name, gramps, varNode);

  if (isObjLit && n.canEliminate()) {
    varNode.removeChild(ref.node);
    if (!varNode.hasChildren()) {
      gramps.removeChild(varNode);
    }
    numChanges++;

    // Clear out the object reference, since we've eliminated it from the
    // parse tree.
    ref.node = null;
  }

  if (numChanges > 0) {
    compiler.reportCodeChange();
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Finds all defines, and creates a {@link DefineInfo} data structure for
 * each one.
 * @return A map of {@link DefineInfo} structures, keyed by name.
 */
private Map<String, DefineInfo> collectDefines(Node root,
    GlobalNamespace namespace) {
  // Find all the global names with a @define annotation
  List<Name> allDefines = Lists.newArrayList();
  for (Name name : namespace.getNameIndex().values()) {
    if (name.docInfo != null && name.docInfo.isDefine()) {
      // Process defines should not depend on check types being enabled,
      // so we look for the JSDoc instead of the inferred type.
      if (isValidDefineType(name.docInfo.getType())) {
        allDefines.add(name);
      } else {
        JSError error = JSError.make(
            name.declaration.sourceName,
            name.declaration.node,
            INVALID_DEFINE_TYPE_ERROR);
        compiler.report(error);
      }
    } else if (name.refs != null) {
      for (Ref ref : name.refs) {
        Node n = ref.node;
        Node parent = ref.node.getParent();
        JSDocInfo info = n.getJSDocInfo();
        if (info == null &&
            parent.getType() == Token.VAR && parent.hasOneChild()) {
          info = parent.getJSDocInfo();
        }

        if (info != null && info.isDefine()) {
          allDefines.add(name);
          break;
        }
      }
    }
  }

  CollectDefines pass = new CollectDefines(compiler, allDefines);
  NodeTraversal.traverse(compiler, root, pass);
  return pass.getAllDefines();
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
CollectDefines(AbstractCompiler compiler, List<Name> listOfDefines) {
  this.compiler = compiler;
  this.allDefines = Maps.newHashMap();

  assignableDefines = Maps.newHashMap();
  assignAllowed = new ArrayDeque<Integer>();
  assignAllowed.push(1);

  // Create a map of references to defines keyed by node for easy lookup
  allRefInfo = Maps.newHashMap();
  for (Name name : listOfDefines) {
    Ref decl = name.getDeclaration();
    if (decl != null) {
      allRefInfo.put(decl.node,
                     new RefInfo(decl, name));
    }
    for (Ref ref : name.getRefs()) {
      if (ref == decl) {
        // Declarations were handled above.
        continue;
      }

      // If there's a TWIN def, only put one of the twins in.
      if (ref.getTwin() == null || !ref.getTwin().isSet()) {
        allRefInfo.put(ref.node, new RefInfo(ref, name));
      }
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * Gets the parent node of the value for any assignment to a Name.
 * For example, in the assignment
 * {@code var x = 3;}
 * the parent would be the NAME node.
 */
private static Node getValueParent(Ref ref) {
  // there are two types of declarations: VARs and ASSIGNs
  return ref.node.getParent() != null &&
      ref.node.getParent().isVar() ?
      ref.node : ref.node.getParent();
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref; //导入依赖的package包/类
/**
 * For each qualified name N in the global scope, we check if:
 * (a) No ancestor of N is ever aliased or assigned an unknown value type.
 *     (If N = "a.b.c", "a" and "a.b" are never aliased).
 * (b) N has exactly one write, and it lives in the global scope.
 * (c) N is aliased in a local scope.
 *
 * If (a) is true, then GlobalNamespace must know all the writes to N.
 * If (a) and (b) are true, then N cannot change during the execution of
 *    a local scope.
 * If (a) and (b) and (c) are true, then the alias can be inlined if the
 *    alias obeys the usual rules for how we decide whether a variable is
 *    inlineable.
 * @see InlineVariables
 */
private void inlineAliases(GlobalNamespace namespace) {
  // Invariant: All the names in the worklist meet condition (a).
  Deque<Name> workList = new ArrayDeque<Name>(namespace.getNameForest());
  while (!workList.isEmpty()) {
    Name name = workList.pop();

    // Don't attempt to inline a getter or setter property as a variable.
    if (name.type == Name.Type.GET || name.type == Name.Type.SET) {
      continue;
    }

    if (name.globalSets == 1 && name.localSets == 0 &&
        name.aliasingGets > 0) {
      // {@code name} meets condition (b). Find all of its local aliases
      // and try to inline them.
      List<Ref> refs = Lists.newArrayList(name.getRefs());
      for (Ref ref : refs) {
        if (ref.type == Type.ALIASING_GET && ref.scope.isLocal()) {
          // {@code name} meets condition (c). Try to inline it.
          if (inlineAliasIfPossible(ref, namespace)) {
            name.removeRef(ref);
          }
        }
      }
    }

    // Check if {@code name} has any aliases left after the
    // local-alias-inlining above.
    if ((name.type == Name.Type.OBJECTLIT ||
         name.type == Name.Type.FUNCTION) &&
        name.aliasingGets == 0 && name.props != null) {
      // All of {@code name}'s children meet condition (a), so they can be
      // added to the worklist.
      workList.addAll(name.props);
    }
  }
}