Exemple #1
0
  /** 12.6.4 begin 'for-in' statement. */
  @Override
  public void visit(BeginForInNode n, State state) {
    if (!Options.get().isForInSpecializationDisabled()) {
      // 1. Find properties to iterate through
      Value v1 = state.readRegister(n.getObjectRegister());
      state.writeRegister(
          n.getObjectRegister(), v1.makeExtendedScope()); // preserve the register value
      v1 = UnknownValueResolver.getRealValue(v1, state);
      Set<ObjectLabel> objs = Conversion.toObjectLabels(state, n, v1, c);
      State.Properties p = state.getEnumProperties(objs);
      Collection<Value> propertyNameValues = newList(p.toValues());

      // Add the no-iteration case
      propertyNameValues.add(Value.makeNull().makeExtendedScope());

      // 2. Make specialized context for each iteration
      int it = n.getPropertyListRegister();
      //            List<Context> specialized_contexts = newList();
      BasicBlock successor = n.getBlock().getSingleSuccessor();
      for (Value k : propertyNameValues) {
        m.visitPropertyRead(n, objs, k, state, true);
        if (!c.isScanning()) {
          // 2.1 Make specialized context
          State specialized_state = state.clone();
          specialized_state.writeRegister(it, k);
          Context specialized_context =
              c.getAnalysis()
                  .getContextSensitivityStrategy()
                  .makeForInEntryContext(state.getContext(), n, k);
          //                    specialized_contexts.add(specialized_context);
          specialized_state.setContext(specialized_context);
          specialized_state.setBasicBlock(successor);
          // 2.2  Propagate specialized context
          c.propagateToFunctionEntry(
              n, state.getContext(), specialized_state, specialized_context, successor);
        }
      }
      if (!c.isScanning()) {
        // TODO: could kill flow to specializations if covered by other context
        // List<Context> previousSpecializations = c.getAnalysis().getForInSpecializations(n,
        // s.getContext());
        // if (previousSpecializations != null && (p.isArray() || p.isNonArray())) {
        //    previousSpecializations.forEach(c -> {
        //        // covered.setToNone();
        //    });
        //  }

        // TODO: could kill null flow unless all iterations has reached at least one EndForInNode
      }
      state.setToNone();
    } else { // fall back to simple mode without context specialization
      Value v1 = state.readRegister(n.getObjectRegister());
      state.writeRegister(
          n.getObjectRegister(), v1.makeExtendedScope()); // preserve the register value
      v1 = UnknownValueResolver.getRealValue(v1, state);
      Set<ObjectLabel> objs = Conversion.toObjectLabels(state, n, v1, c);
      Properties p = state.getEnumProperties(objs);
      Value proplist = p.toValue().joinNull();
      m.visitPropertyRead(n, objs, proplist, state, true);
      state.writeRegister(n.getPropertyListRegister(), proplist);
    }
  }