Java DiGraphNode.getAnnotation方法代码示例

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
protected void joinInputs(DiGraphNode<N, Branch> node) {
  BranchedFlowState<L> state = node.getAnnotation();
  List<DiGraphNode<N, Branch>> predNodes =
      getCfg().getDirectedPredNodes(node);
  List<L> values = new ArrayList<L>(predNodes.size());

  for (DiGraphNode<N, Branch> predNode : predNodes) {
    BranchedFlowState<L> predNodeState = predNode.getAnnotation();

    L in = predNodeState.out.get(
        getCfg().getDirectedSuccNodes(predNode).indexOf(node));

    values.add(in);
  }
  if (getCfg().getEntry() == node) {
    state.setIn(createEntryLattice());
  } else if (!values.isEmpty()) {
    state.setIn(joinOp.apply(values));
  }
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (parent == null) {
    return;
  }
  if (n.isFunction() || n.isScript()) {
    return;
  }

  DiGraphNode<Node, Branch> gNode = cfg.getDirectedGraphNode(n);
  if (gNode == null) { // Not in CFG.
    return;
  }
  if (gNode.getAnnotation() != GraphReachability.REACHABLE ||
      (removeNoOpStatements && !NodeUtil.mayHaveSideEffects(n, compiler))) {
    removeDeadExprStatementSafely(n);
    return;
  }

  tryRemoveUnconditionalBranching(n);
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (parent == null || n.isFunction() || n.isScript()) {
    return;
  }
  DiGraphNode<Node, Branch> gNode = cfg.getDirectedGraphNode(n);
  if (gNode == null) { // Not in CFG.
    return;
  }
  if (gNode.getAnnotation() != GraphReachability.REACHABLE
      || !NodeUtil.mayHaveSideEffects(n, compiler)) {
    removeDeadExprStatementSafely(n);
    return;
  }
  tryRemoveUnconditionalBranching(n);
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
protected void joinInputs(DiGraphNode<N, Branch> node) {
  BranchedFlowState<L> state = node.getAnnotation();
  List<DiGraphNode<N, Branch>> predNodes =
      getCfg().getDirectedPredNodes(node);
  List<L> values = new ArrayList<>(predNodes.size());

  for (DiGraphNode<N, Branch> predNode : predNodes) {
    BranchedFlowState<L> predNodeState = predNode.getAnnotation();

    L in = predNodeState.out.get(
        getCfg().getDirectedSuccNodes(predNode).indexOf(node));

    values.add(in);
  }
  if (getCfg().getEntry() == node) {
    state.setIn(createEntryLattice());
  } else if (!values.isEmpty()) {
    state.setIn(joinOp.apply(values));
  }
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (parent == null || n.isFunction() || n.isScript()) {
    return;
  }
  DiGraphNode<Node, Branch> gNode = cfg.getDirectedGraphNode(n);
  if (gNode == null) { // Not in CFG.
    return;
  }
  if (gNode.getAnnotation() != GraphReachability.REACHABLE ||
      (removeNoOpStatements && !NodeUtil.mayHaveSideEffects(n, compiler))) {
    removeDeadExprStatementSafely(n);
    return;
  }
  tryRemoveUnconditionalBranching(n);
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
/**
 * Performs a single flow through a node.
 *
 * @return {@code true} if the flow state differs from the previous state.
 */
protected boolean flow(DiGraphNode<N, Branch> node) {
  FlowState<L> state = node.getAnnotation();
  if (isForward()) {
    L outBefore = state.out;
    state.out = flowThrough(node.getValue(), state.in);
    return !outBefore.equals(state.out);
  } else {
    L inBefore = state.in;
    state.in = flowThrough(node.getValue(), state.out);
    return !inBefore.equals(state.in);
  }
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
/**
 * Returns the lattice element at the exit point. Needs to be overridden
 * because we use a BranchedFlowState instead of a FlowState; ugh.
 */
@Override
L getExitLatticeElement() {
  DiGraphNode<N, Branch> node = getCfg().getImplicitReturn();
  BranchedFlowState<L> state = node.getAnnotation();
  return state.getIn();
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
/**
 * Try to remove useless assignments from a control flow graph that has been
 * annotated with liveness information.
 *
 * @param t The node traversal.
 * @param cfg The control flow graph of the program annotated with liveness
 *        information.
 */
private void tryRemoveDeadAssignments(NodeTraversal t,
    ControlFlowGraph<Node> cfg) {
  List<DiGraphNode<Node, Branch>> nodes = cfg.getDirectedGraphNodes();

  for (DiGraphNode<Node, Branch> cfgNode : nodes) {
    FlowState<LiveVariableLattice> state =
        cfgNode.getAnnotation();
    Node n = cfgNode.getValue();
    if (n == null) {
      continue;
    }
    switch (n.getType()) {
      case Token.IF:
      case Token.WHILE:
      case Token.DO:
        tryRemoveAssignment(t, NodeUtil.getConditionExpression(n), state);
        continue;
      case Token.FOR:
        if (!NodeUtil.isForIn(n)) {
          tryRemoveAssignment(
              t, NodeUtil.getConditionExpression(n), state);
        }
        continue;
      case Token.SWITCH:
      case Token.CASE:
      case Token.RETURN:
        if (n.hasChildren()) {
          tryRemoveAssignment(t, n.getFirstChild(), state);
        }
        continue;
      // TODO(user): case Token.VAR: Remove var a=1;a=2;.....
    }
    
    tryRemoveAssignment(t, n, state);
  }
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
private void discoverBackEdges(DiGraphNode<N, E> u) {
  u.setAnnotation(GRAY);
  for (DiGraphEdge<N, E> e : u.getOutEdges()) {
    if (ignoreEdge(e)) {
      continue;
    }
    DiGraphNode<N, E> v = e.getDestination();
    if (v.getAnnotation() == WHITE) {
      discoverBackEdges(v);
    } else if (v.getAnnotation() == GRAY) {
      e.setAnnotation(BACK_EDGE);
    }
  }
  u.setAnnotation(BLACK);
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
  if (parent == null) {
    return;
  }
  if (n.getType() == Token.FUNCTION || n.getType() == Token.SCRIPT) {
    return;
  }
  // Removes TRYs that had its CATCH removed and/or empty FINALLY.
  // TODO(dcc): Move the parts of this that don't require a control flow
  // graph to PeepholeRemoveDeadCode
  if (n.getType() == Token.TRY) {
    Node body = n.getFirstChild();
    Node catchOrFinallyBlock = body.getNext();
    Node finallyBlock = catchOrFinallyBlock.getNext();

    if (!catchOrFinallyBlock.hasChildren() &&
        (finallyBlock == null || !finallyBlock.hasChildren())) {
      n.removeChild(body);
      parent.replaceChild(n, body);
      compiler.reportCodeChange();
      n = body;
    }
  }
  DiGraphNode<Node, Branch> gNode = curCfg.getDirectedGraphNode(n);
  if (gNode == null) { // Not in CFG.
    return;
  }
  if (gNode.getAnnotation() != GraphReachability.REACHABLE ||
      (removeNoOpStatements && !NodeUtil.mayHaveSideEffects(n))) {
    removeDeadExprStatementSafely(n);
    return;
  }

  tryRemoveUnconditionalBranching(n);
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
/**
 * Try to remove useless assignments from a control flow graph that has been
 * annotated with liveness information.
 *
 * @param t The node traversal.
 * @param cfg The control flow graph of the program annotated with liveness
 *        information.
 */
private void tryRemoveDeadAssignments(NodeTraversal t,
    ControlFlowGraph<Node> cfg) {
  Iterable<DiGraphNode<Node, Branch>> nodes = cfg.getDirectedGraphNodes();

  for (DiGraphNode<Node, Branch> cfgNode : nodes) {
    FlowState<LiveVariableLattice> state =
        cfgNode.getAnnotation();
    Node n = cfgNode.getValue();
    if (n == null) {
      continue;
    }
    switch (n.getType()) {
      case Token.IF:
      case Token.WHILE:
      case Token.DO:
        tryRemoveAssignment(t, NodeUtil.getConditionExpression(n), state);
        continue;
      case Token.FOR:
        if (!NodeUtil.isForIn(n)) {
          tryRemoveAssignment(
              t, NodeUtil.getConditionExpression(n), state);
        }
        continue;
      case Token.SWITCH:
      case Token.CASE:
      case Token.RETURN:
        if (n.hasChildren()) {
          tryRemoveAssignment(t, n.getFirstChild(), state);
        }
        continue;
      // TODO(user): case Token.VAR: Remove var a=1;a=2;.....
    }

    tryRemoveAssignment(t, n, state);
  }
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
private UndiGraph<Var, Void> computeVariableNamesInterferenceGraph(
    NodeTraversal t, ControlFlowGraph<Node> cfg, Set<Var> escaped) {
  UndiGraph<Var, Void> interferenceGraph =
      new LinkedUndirectedGraph<Var, Void>();
  Scope scope = t.getScope();

  // First create a node for each non-escaped variable.
  for (Iterator<Var> i = scope.getVars(); i.hasNext();) {
    Var v = i.next();
    if (!escaped.contains(v)) {
      
      // TODO(user): In theory, we CAN coalesce function names just like
      // any variables. Our Liveness analysis captures this just like it as
      // described in the specification. However, we saw some zipped and
      // and unzipped size increase after this. We are not totally sure why
      // that is but, for now, we will respect the dead functions and not play
      // around with it.
      if (!NodeUtil.isFunction(v.getParentNode())) {
        interferenceGraph.createNode(v);
      }
    }
  }

  // Go through every single point of the program and look at each variable
  // pairs. If they are both live at the same time, at an edge between them.
  for (DiGraphNode<Node, Branch> cfgNode : cfg.getDirectedGraphNodes()) {
    FlowState<LiveVariableLattice> state = cfgNode.getAnnotation();
    if (cfg.isImplicitReturn(cfgNode)) {
      continue;
    }

    int varsInScope = scope.getVarCount();
    ArrayList<CombinedLiveRangeChecker> rangesToCheck =
        new ArrayList<CombinedLiveRangeChecker>(
            varsInScope * varsInScope);

    for (Iterator<Var> i1 = scope.getVars(); i1.hasNext();) {
      Var v1 = i1.next();
      for (Iterator<Var> i2 = scope.getVars(); i2.hasNext();) {
        Var v2 = i2.next();

        if (v1 == v2 || !interferenceGraph.hasNode(v1) ||
            !interferenceGraph.hasNode(v2)) {
          // Skip nodes that were not added. They are globals and escaped
          // locals. Also avoid merging a variable with itself.
          continue;
        }

        boolean v1OutLive = state.getOut().isLive(v1);
        boolean v2OutLive = state.getOut().isLive(v2);
        // Finally, check the live states and add edge when possible.
        if (v1.getParentNode().getType() == Token.LP &&
            v2.getParentNode().getType() == Token.LP) {
          interferenceGraph.connectIfNotFound(v1, null, v2);
        } else if ((state.getIn().isLive(v1) && state.getIn().isLive(v2)) ||
            (v1OutLive && v2OutLive)) {
          interferenceGraph.connectIfNotFound(v1, null, v2);
        } else {
          LiveRangeChecker checker1 =
              new LiveRangeChecker(v1, v2OutLive ? null : v2);
          LiveRangeChecker checker2 =
              new LiveRangeChecker(v2, v1OutLive ? null : v1);
          rangesToCheck.add(new CombinedLiveRangeChecker(checker1, checker2));
        }
      }
    }

    // Do the collected live range checks.
    checkRanges(rangesToCheck, cfgNode.getValue());
    for (CombinedLiveRangeChecker range : rangesToCheck) {
      range.connectIfCrossed(interferenceGraph);
    }
  }
  return interferenceGraph;
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
private UndiGraph<Var, Void> computeVariableNamesInterferenceGraph(
    NodeTraversal t, ControlFlowGraph<Node> cfg, Set<Var> escaped) {
  UndiGraph<Var, Void> interferenceGraph =
      new LinkedUndirectedGraph<Var, Void>();
  Scope scope = t.getScope();

  // First create a node for each non-escaped variable.
  for (Iterator<Var> i = scope.getVars(); i.hasNext();) {
    Var v = i.next();
    if (!escaped.contains(v)) {

      // TODO(user): In theory, we CAN coalesce function names just like
      // any variables. Our Liveness analysis captures this just like it as
      // described in the specification. However, we saw some zipped and
      // and unzipped size increase after this. We are not totally sure why
      // that is but, for now, we will respect the dead functions and not play
      // around with it.
      if (!NodeUtil.isFunction(v.getParentNode())) {
        interferenceGraph.createNode(v);
      }
    }
  }

  // Go through every single point of the program and look at each variable
  // pairs. If they are both live at the same time, at an edge between them.
  for (DiGraphNode<Node, Branch> cfgNode : cfg.getDirectedGraphNodes()) {
    FlowState<LiveVariableLattice> state = cfgNode.getAnnotation();
    if (cfg.isImplicitReturn(cfgNode)) {
      continue;
    }

    int varsInScope = scope.getVarCount();
    ArrayList<CombinedLiveRangeChecker> rangesToCheck =
        new ArrayList<CombinedLiveRangeChecker>(
            varsInScope * varsInScope);

    for (Iterator<Var> i1 = scope.getVars(); i1.hasNext();) {
      Var v1 = i1.next();
      for (Iterator<Var> i2 = scope.getVars(); i2.hasNext();) {
        Var v2 = i2.next();

        if (v1 == v2 || !interferenceGraph.hasNode(v1) ||
            !interferenceGraph.hasNode(v2)) {
          // Skip nodes that were not added. They are globals and escaped
          // locals. Also avoid merging a variable with itself.
          continue;
        }

        boolean v1OutLive = state.getOut().isLive(v1);
        boolean v2OutLive = state.getOut().isLive(v2);
        // Finally, check the live states and add edge when possible.
        if (v1.getParentNode().getType() == Token.LP &&
            v2.getParentNode().getType() == Token.LP) {
          interferenceGraph.connectIfNotFound(v1, null, v2);
        } else if ((state.getIn().isLive(v1) && state.getIn().isLive(v2)) ||
            (v1OutLive && v2OutLive)) {
          interferenceGraph.connectIfNotFound(v1, null, v2);
        } else {
          LiveRangeChecker checker1 =
              new LiveRangeChecker(v1, v2OutLive ? null : v2);
          LiveRangeChecker checker2 =
              new LiveRangeChecker(v2, v1OutLive ? null : v1);
          rangesToCheck.add(new CombinedLiveRangeChecker(checker1, checker2));
        }
      }
    }

    // Do the collected live range checks.
    checkRanges(rangesToCheck, cfgNode.getValue());
    for (CombinedLiveRangeChecker range : rangesToCheck) {
      range.connectIfCrossed(interferenceGraph);
    }
  }
  return interferenceGraph;
}
 

import com.google.javascript.jscomp.graph.DiGraph.DiGraphNode; //导入方法依赖的package包/类
/**
 * Try to remove useless assignments from a control flow graph that has been
 * annotated with liveness information.
 *
 * @param t The node traversal.
 * @param cfg The control flow graph of the program annotated with liveness
 *        information.
 */
private void tryRemoveDeadAssignments(NodeTraversal t,
    ControlFlowGraph<Node> cfg,
    Map<String, Var> allVarsInFn) {
  Iterable<DiGraphNode<Node, Branch>> nodes = cfg.getDirectedGraphNodes();

  for (DiGraphNode<Node, Branch> cfgNode : nodes) {
    FlowState<LiveVariableLattice> state =
        cfgNode.getAnnotation();
    Node n = cfgNode.getValue();
    if (n == null) {
      continue;
    }
    switch (n.getToken()) {
      case IF:
      case WHILE:
      case DO:
        tryRemoveAssignment(t, NodeUtil.getConditionExpression(n), state, allVarsInFn);
        continue;
      case FOR:
      case FOR_IN:
      case FOR_OF:
        if (n.isVanillaFor()) {
          tryRemoveAssignment(t, NodeUtil.getConditionExpression(n), state, allVarsInFn);
        }
        continue;
      case SWITCH:
      case CASE:
      case RETURN:
        if (n.hasChildren()) {
          tryRemoveAssignment(t, n.getFirstChild(), state, allVarsInFn);
        }
        continue;
        // TODO(user): case VAR: Remove var a=1;a=2;.....
      default:
        break;
    }

    tryRemoveAssignment(t, n, state, allVarsInFn);
  }
}