/** 11.1.2 assignment with right-hand-side identifier reference. */
@Override
public void visit(ReadVariableNode n, State state) {
String varname = n.getVariableName();
Value v;
if (varname.equals("this")) {
// 11.1.1 read 'this' from the execution context
v = state.readThis();
m.visitReadThis(n, v, state, InitialStateBuilder.GLOBAL);
} else { // ordinary variable
int result_base_reg = n.getResultBaseRegister();
Set<ObjectLabel> base_objs = null;
if (c.isScanning() || result_base_reg != AbstractNode.NO_VALUE) base_objs = newSet();
v = state.readVariable(varname, base_objs);
m.visitPropertyRead(n, base_objs, Value.makeTemporaryStr(varname), state, true);
m.visitVariableAsRead(n, v, state);
m.visitVariableOrProperty(varname, n.getSourceLocation(), v, state.getContext(), state);
m.visitReadNonThisVariable(n, v);
if (v.isMaybeAbsent()) Exceptions.throwReferenceError(state, c);
if (v.isNotPresent() && !Options.get().isPropagateDeadFlow()) {
state.setToNone();
return;
}
if (result_base_reg != AbstractNode.NO_VALUE)
state.writeRegister(result_base_reg, Value.makeObject(base_objs)); // see 10.1.4
m.visitRead(n, v, state);
m.visitReadVariable(n, v, state); // TODO: combine some of these m.visitXYZ methods?
}
if (v.isNotPresent() && !Options.get().isPropagateDeadFlow()) {
state.setToNone();
return;
}
if (n.getResultRegister() != AbstractNode.NO_VALUE)
state.writeRegister(n.getResultRegister(), v.restrictToNotAbsent());
}
/** 12.6.4 end of loop of 'for-in' statement. */
@Override
public void visit(EndForInNode n, State state) {
if (!Options.get().isForInSpecializationDisabled()) {
if (!c.isScanning()) {
// 1. Find successor block, context and base-state
BasicBlock successor = state.getBasicBlock().getSingleSuccessor();
for (Pair<NodeAndContext<Context>, Context> ncc :
c.getAnalysisLatticeElement()
.getCallGraph()
.getSources(BlockAndContext.makeEntry(n.getBlock(), state.getContext()))) {
State nonSpecializedMergeState = state.clone();
Context nonSpecializedContext = ncc.getFirst().getContext();
// 2. Use State.mergeFunctionReturn to do the merge
State forInBeginState =
c.getAnalysisLatticeElement()
.getState(
n.getBlock().getEntryBlock().getEntryPredecessorBlock(),
nonSpecializedContext);
State forInEntryState =
c.getAnalysisLatticeElement()
.getState(n.getBlock().getEntryBlock(), state.getContext());
Value returnValue =
nonSpecializedMergeState.mergeFunctionReturn(
forInBeginState,
forInBeginState,
forInEntryState,
nonSpecializedMergeState.getSummarized(),
nonSpecializedMergeState.readRegister(AbstractNode.RETURN_REG));
nonSpecializedMergeState.setContext(nonSpecializedContext);
nonSpecializedMergeState.writeRegister(AbstractNode.RETURN_REG, returnValue);
if (state.hasExceptionRegisterValue()) {
nonSpecializedMergeState.writeRegister(
AbstractNode.EXCEPTION_REG, state.readRegister(AbstractNode.EXCEPTION_REG));
}
// 3. Propagate only to the non-specialized successor
nonSpecializedMergeState.setBasicBlock(n.getBlock().getSingleSuccessor());
c.propagateToBasicBlock(nonSpecializedMergeState, successor, nonSpecializedContext);
}
state.setToNone();
}
}
}
/** 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);
}
}