/**
* Removes unreferenced arguments from a function declaration and when possible the function's
* callSites.
*
* @param fnScope The scope inside the function
*/
private void removeUnreferencedFunctionArgs(Scope fnScope) {
// TODO(johnlenz): Update type registry for function signature changes.
Node function = fnScope.getRootNode();
Preconditions.checkState(function.getType() == Token.FUNCTION);
if (NodeUtil.isGetOrSetKey(function.getParent())) {
// The parameters object literal setters can not be removed.
return;
}
Node argList = getFunctionArgList(function);
boolean modifyCallers = modifyCallSites && callSiteOptimizer.canModifyCallers(function);
if (!modifyCallers) {
// Strip unreferenced args off the end of the function declaration.
Node lastArg;
while ((lastArg = argList.getLastChild()) != null) {
Var var = fnScope.getVar(lastArg.getString());
if (!referenced.contains(var)) {
Preconditions.checkNotNull(var == null);
argList.removeChild(lastArg);
compiler.reportCodeChange();
} else {
break;
}
}
} else {
callSiteOptimizer.optimize(fnScope, referenced);
}
}
@Override
public void process(Node externs, Node root, SimpleDefinitionFinder defFinder) {
if (modifyCallSites) {
Preconditions.checkNotNull(defFinder);
callSiteOptimizer = new CallSiteOptimizer(compiler, defFinder);
}
traverseAndRemoveUnusedReferences(root);
if (callSiteOptimizer != null) {
callSiteOptimizer.applyChanges();
}
}