private function tryRemoveDeadAssignments(NodeTraversal $t, ControlFlowGraph $cfg)
{
$nodes = $cfg->getDirectedGraphNodes();
foreach ($nodes as $cfgNode) {
$inState = $cfgNode->getAttribute(DataFlowAnalysis::ATTR_FLOW_STATE_IN);
$outState = $cfgNode->getAttribute(DataFlowAnalysis::ATTR_FLOW_STATE_OUT);
$n = $cfgNode->getAstNode();
if (null === $n) {
continue;
}
switch (true) {
case $n instanceof \PHPParser_Node_Stmt_If:
case $n instanceof \PHPParser_Node_Stmt_ElseIf:
case $n instanceof \PHPParser_Node_Stmt_While:
case $n instanceof \PHPParser_Node_Stmt_Do:
case $n instanceof \PHPParser_Node_Stmt_For:
case $n instanceof \PHPParser_Node_Stmt_Switch:
case $n instanceof \PHPParser_Node_Stmt_Case:
if (null !== ($condition = NodeUtil::getConditionExpression($n))) {
$this->tryRemoveAssignment($t, $condition, null, $inState, $outState);
}
continue 2;
case $n instanceof \PHPParser_Node_Stmt_Return:
if (null !== $n->expr) {
$this->tryRemoveAssignment($t, $n->expr, null, $inState, $outState);
}
continue 2;
}
$this->tryRemoveAssignment($t, $n, null, $inState, $outState);
}
}
