public function serialize(ControlFlowGraph $graph)
{
$dot = "digraph G {\n";
$this->ids = new \SplObjectStorage();
$this->idCount = 0;
$dot .= " " . $this->getId($graph->getImplicitReturn()) . " [shape=box,label=\"implicit return\",style=filled]\n";
$entryPoint = $graph->getEntryPoint();
$nodes = $graph->getNodes();
foreach ($nodes as $astNode) {
$node = $nodes[$astNode];
$id = $this->getId($node);
$dot .= sprintf(' %s [shape=box,label="%s"', $id, str_replace('"', '\\"', NodeUtil::getStringRepr($astNode)));
if ($node === $entryPoint) {
$dot .= ",style=filled";
}
$dot .= "]\n";
foreach ($node->getOutEdges() as $edge) {
$dot .= sprintf(" %s -> %s", $id, $this->getId($edge->getDest()));
switch ($edge->getType()) {
case GraphEdge::TYPE_ON_FALSE:
$dot .= ' [label="false"]';
break;
case GraphEdge::TYPE_ON_TRUE:
$dot .= ' [label="true"]';
break;
case GraphEdge::TYPE_ON_EX:
$dot .= ' [label="exception"]';
break;
}
$dot .= "\n";
}
}
$dot .= "}";
return $dot;
}
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);
}
}
private function connectToPossibleExceptionHandler(\PHPParser_Node $cfgNode, \PHPParser_Node $target)
{
if (!self::mayThrowException($target)) {
return;
}
if ($this->exceptionHandlers->isEmpty()) {
return;
}
foreach ($this->exceptionHandlers as $handler) {
assert($handler instanceof \PHPParser_Node_Stmt_TryCatch);
$catches = $handler->catches;
$this->graph->connectIfNotConnected($cfgNode, GraphEdge::TYPE_ON_EX, $catches[0]);
break;
}
}
public function testComputeFixedPoint()
{
$graph = new ControlFlowGraph($entry = $this->getAstNode());
$node1 = $this->getAstNode();
$graph->connect($entry, null, $node1);
$node2 = $this->getAstNode();
$graph->connect($node1, null, $node2);
$node3 = $this->getAstNode();
$graph->connect($node3, null, $node2);
$node4 = $this->getAstNode();
$graph->connect($node2, null, $node4);
$callback = $this->getMock('Scrutinizer\\PhpAnalyzer\\ControlFlow\\EdgeCallbackInterface');
$t = new FixedPointGraphTraversal($callback);
$callback->expects($this->at(0))->method('traverseEdge')->with($entry, null, $node1)->will($this->returnValue(true));
$callback->expects($this->at(1))->method('traverseEdge')->with($node1, null, $node2)->will($this->returnValue(false));
$t->computeFixedPointWithEntry($graph, $entry);
}
public function testBranchedSimpleIf()
{
// if (a) { a = 0; } else { b = 0; } c = b;
$a = new Variable('a');
$b = new Variable('b');
$c = new Variable('c');
$inst1 = new BranchInstruction($a);
$inst2 = ArithmeticInstruction::newAssignNumberToVariableInstruction($a, 0);
$inst3 = ArithmeticInstruction::newAssignNumberToVariableInstruction($b, 0);
$inst4 = ArithmeticInstruction::newAssignVariableToVariableInstruction($c, $b);
$cfg = new ControlFlowGraph($inst1);
$cfg->connectIfNotConnected($inst1, GraphEdge::TYPE_ON_TRUE, $inst2);
$cfg->connectIfNotConnected($inst1, GraphEdge::TYPE_ON_FALSE, $inst3);
$cfg->connectIfNotConnected($inst2, GraphEdge::TYPE_UNCOND, $inst4);
$cfg->connectIfNotConnected($inst3, GraphEdge::TYPE_UNCOND, $inst4);
$n1 = $cfg->getNode($inst1);
$n2 = $cfg->getNode($inst2);
$n3 = $cfg->getNode($inst3);
$n4 = $cfg->getNode($inst4);
$constProp = new BranchedDummyConstPropagation($cfg);
$constProp->analyze();
// We cannot conclude anything from if(a).
$this->verifyInHas($n1, $a, null);
$this->verifyInHas($n1, $b, null);
$this->verifyInHas($n1, $c, null);
// Nothing is known on the true branch.
$this->verifyInHas($n2, $a, null);
$this->verifyInHas($n2, $b, null);
$this->verifyInHas($n2, $c, null);
// Verify that we have a = 0 on the false branch.
$this->verifyInHas($n3, $a, 0);
$this->verifyInHas($n3, $b, null);
$this->verifyInHas($n3, $c, null);
// After the merge we should still have a = 0.
$this->verifyInHas($n4, $a, 0);
}
