import com.google.javascript.jscomp.GlobalNamespace.Ref.Type; //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.Type; //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.Type; //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);
    }
  }
}
 

import com.google.javascript.jscomp.GlobalNamespace.Ref.Type; //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.aliasingGets > 0 || name.localSets + name.globalSets > 1 ||
         name.deleteProps > 0)) {
      boolean initialized = name.getDeclaration() != null;
      for (Ref ref : name.getRefs()) {
        if (ref == name.getDeclaration()) {
          continue;
        }

        if (ref.type == Ref.Type.DELETE_PROP) {
          if (initialized) {
            warnAboutNamespaceRedefinition(name, ref);
          }
        } else 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.Type; //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. (d) N is aliased in global scope
 *
 * <p>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. If (a) and (b) and (d) are true, then inline the alias if possible (if
 * it is assigned exactly once unconditionally).
 *
 * <p>For (a), (b), and (c) are true and the alias is of a constructor, we may also partially
 * inline the alias - i.e. replace some references with the constructor but not all - since
 * constructor properties are always collapsed, so we want to be more aggressive about removing
 * aliases.
 *
 * @see InlineVariables
 */
private void inlineAliases(GlobalNamespace namespace) {
  // Invariant: All the names in the worklist meet condition (a).
  Deque<Name> workList = new ArrayDeque<>(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.inExterns && 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 = new ArrayList<>(name.getRefs());
      for (Ref ref : refs) {
        Scope hoistScope = ref.scope.getClosestHoistScope();
        if (ref.type == Type.ALIASING_GET && !mayBeGlobalAlias(ref) && ref.getTwin() == null) {
          // {@code name} meets condition (c). Try to inline it.
          // TODO(johnlenz): consider picking up new aliases at the end
          // of the pass instead of immediately like we do for global
          // inlines.
          if (inlineAliasIfPossible(name, ref, namespace)) {
            name.removeRef(ref);
          }
        } else if (ref.type == Type.ALIASING_GET
            && hoistScope.isGlobal()
            && ref.getTwin() == null) { // ignore aliases in chained assignments
          if (inlineGlobalAliasIfPossible(name, ref, namespace)) {
            name.removeRef(ref);
          }
        }
      }
    }

    if (!name.inExterns && name.type == Name.Type.CLASS) {
      List<Name> subclasses = name.subclasses;
      if (subclasses != null && name.props != null) {
        for (Name subclass : subclasses) {
          for (Name prop : name.props) {
            rewriteAllSubclassInheritedAccesses(name, subclass, prop, namespace);
          }
        }
      }
    }

    // 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.type == Name.Type.CLASS)
        && 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.Type; //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.
 * (d) N is aliased in global 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.
 * If (a) and (b) and (d) are true, then inline the alias if possible (if
 * it is assigned exactly once unconditionally).
 * @see InlineVariables
 */
private void inlineAliases(GlobalNamespace namespace) {
  // Invariant: All the names in the worklist meet condition (a).
  Deque<Name> workList = new ArrayDeque<>(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.inExterns && 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.
          // TODO(johnlenz): consider picking up new aliases at the end
          // of the pass instead of immediately like we do for global
          // inlines.
          if (inlineAliasIfPossible(ref, namespace)) {
            name.removeRef(ref);
          }
        } else if (ref.type == Type.ALIASING_GET
            && ref.scope.isGlobal()
            && ref.getTwin() == null) {  // ignore aliases in chained assignments
          if (inlineGlobalAliasIfPossible(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.Type; //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.
 * (d) N is aliased in global 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.
 * If (a) and (b) and (d) are true, then inline the alias if possible (if
 * it is assigned exactly once unconditionally).
 * @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.inExterns && 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.
          // TODO(johnlenz): consider picking up new aliases at the end
          // of the pass instead of immediately like we do for global
          // inlines.
          if (inlineAliasIfPossible(ref, namespace)) {
            name.removeRef(ref);
          }
        } else if (ref.type == Type.ALIASING_GET
            && ref.scope.isGlobal()
            && ref.getTwin() == null) {  // ignore aliases in chained assignments
          if (inlineGlobalAliasIfPossible(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);
    }
  }
}