public void Dominates()
{
var cfg = new Graph();
cfg.Nodes.Add("1");
cfg.Nodes.Add("2");
cfg.Nodes.Add("3");
cfg.Nodes.Add("4");
cfg.Edges.Add("1", "2");
cfg.Edges.Add("2", "3");
cfg.Edges.Add("3", "4");
var info = new DominatorInfo(cfg.Nodes["1"]);
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["1"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["2"], cfg.Nodes["1"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["3"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["3"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["2"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["4"], cfg.Nodes["4"]));
}
public void LoopFrontiers()
{
var info = new DominatorInfo(LoopGraph.Nodes["1"]);
var frontier = new HashSet <Node>(new[] { LoopGraph.Nodes["2"] });
Assert.Equal(frontier, info.GetDominanceFrontier(LoopGraph.Nodes["2"]));
Assert.Equal(frontier, info.GetDominanceFrontier(LoopGraph.Nodes["3"]));
}
public void LoopHeader()
{
var cfg = LoopGraph;
var info = new DominatorInfo(cfg.Nodes["1"]);
Assert.True(info.IsLoopHeader(cfg.Nodes["2"]));
Assert.False(info.IsLoopHeader(cfg.Nodes["1"]));
}
public void LoopDominators()
{
var info = new DominatorInfo(LoopGraph.Nodes["1"]);
Assert.Equal(LoopGraph.Nodes["1"], info.GetImmediateDominator(LoopGraph.Nodes["1"]));
Assert.Equal(LoopGraph.Nodes["1"], info.GetImmediateDominator(LoopGraph.Nodes["2"]));
Assert.Equal(LoopGraph.Nodes["2"], info.GetImmediateDominator(LoopGraph.Nodes["3"]));
Assert.Equal(LoopGraph.Nodes["2"], info.GetImmediateDominator(LoopGraph.Nodes["4"]));
}
public void IfStatementFrontiers()
{
var cfg = IfStatementGraph;
var info = new DominatorInfo(IfStatementGraph.Nodes["1"]);
var frontier = new HashSet <Node>(new[] { IfStatementGraph.Nodes["4"] });
Assert.Equal(frontier, info.GetDominanceFrontier(IfStatementGraph.Nodes["3"]));
Assert.Equal(frontier, info.GetDominanceFrontier(IfStatementGraph.Nodes["3"]));
}
public void LoopDominated()
{
var cfg = LoopGraph;
var info = new DominatorInfo(LoopGraph.Nodes["1"]);
Assert.True(info.GetDominatedNodes(cfg.Nodes["1"]).SetEquals(cfg.Nodes));
Assert.True(info.GetDominatedNodes(cfg.Nodes["2"]).SetEquals(new[] { cfg.Nodes["2"], cfg.Nodes["3"], cfg.Nodes["4"] }));
Assert.True(info.GetDominatedNodes(cfg.Nodes["3"]).SetEquals(new[] { cfg.Nodes["3"] }));
Assert.True(info.GetDominatedNodes(cfg.Nodes["4"]).SetEquals(new[] { cfg.Nodes["4"] }));
}
public void IfStatementDominated()
{
var cfg = IfStatementGraph;
var info = new DominatorInfo(IfStatementGraph.Nodes["1"]);
Assert.True(info.GetDominatedNodes(cfg.Nodes["1"]).SetEquals(cfg.Nodes));
Assert.True(info.GetDominatedNodes(cfg.Nodes["2"]).SetEquals(new[] { cfg.Nodes["2"] }));
Assert.True(info.GetDominatedNodes(cfg.Nodes["3"]).SetEquals(new[] { cfg.Nodes["3"] }));
Assert.True(info.GetDominatedNodes(cfg.Nodes["4"]).SetEquals(new[] { cfg.Nodes["4"] }));
}
public void IfStatementDominators()
{
var cfg = IfStatementGraph;
var info = new DominatorInfo(cfg.Nodes["1"]);
Assert.Equal(cfg.Nodes["1"], info.GetImmediateDominator(cfg.Nodes["1"]));
Assert.Equal(cfg.Nodes["1"], info.GetImmediateDominator(cfg.Nodes["2"]));
Assert.Equal(cfg.Nodes["1"], info.GetImmediateDominator(cfg.Nodes["3"]));
Assert.Equal(cfg.Nodes["1"], info.GetImmediateDominator(cfg.Nodes["4"]));
}
public ILCompilationUnit(ControlFlowGraph controlFlowGraph, IFrameLayout frameLayout)
{
ControlFlowGraph = controlFlowGraph ?? throw new ArgumentNullException(nameof(controlFlowGraph));
FrameLayout = frameLayout;
DominatorInfo = new DominatorInfo(controlFlowGraph.Entrypoint);
DominatorTree = DominatorInfo.ToDominatorTree();
for (int i = 0; i < frameLayout.Parameters.Count; i++)
{
var parameter = new ILParameter("arg_" + i, i);
Parameters.Add(parameter);
_variables.Add(parameter.Name, parameter);
}
}
public BlockGenerator(ControlFlowGraph cfg, CilCodeGenerator generator)
{
_cfg = cfg ?? throw new ArgumentNullException(nameof(cfg));
_generator = generator;
_dominatorInfo = new DominatorInfo(cfg.Entrypoint);
_dominatorTree = _dominatorInfo.ToDominatorTree();
var components = cfg.Entrypoint.FindStronglyConnectedComponents();
_nodeToComponent = new Dictionary <Node, ISet <Node> >();
foreach (var component in components)
{
foreach (var node in component)
{
_nodeToComponent[node] = component;
}
}
}
private void AddAbnormalEdges(ControlFlowGraph graph)
{
if (graph.SubGraphs.Count == 0)
{
return;
}
// Since exception handlers make it possible to transfer control to the handler block
// at any time, we have these "abnormal edges" from each node in the try block
// to the first node in the handler block (or filter block).
// First, add the initial abnormal handler edges from every try-start to the handler-start (or filter start).
// This allows us to do some more dominator-magic, where we can just infer the handler body based
// on the nodes dominated by the handler node.
foreach (var subGraph in graph.SubGraphs.OrderBy(x => x.Nodes.Count))
{
var ehFrame = (EHFrame)subGraph.UserData[EHFrame.EHFrameProperty];
// Find the try entry node.
var tryEntry = GetNode(graph, (long)ehFrame.TryStart);
tryEntry.UserData[ControlFlowGraph.TryStartProperty] = ehFrame;
// Find the handler entry node.
var handlerEntry = GetNode(graph, (long)ehFrame.HandlerAddress);
handlerEntry.UserData[ControlFlowGraph.HandlerStartProperty] = ehFrame;
// Add initial abnormal edge.
if (ehFrame.Type != EHType.FILTER)
{
// Jump straight to the handler entry.
AddAbnormalEdge(graph, tryEntry, ehFrame, handlerEntry);
}
else
{
// Jump to the filter entry.
var filterEntry = GetNode(graph, (long)ehFrame.FilterAddress);
filterEntry.UserData[ControlFlowGraph.FilterStartProperty] = ehFrame;
AddAbnormalEdge(graph, tryEntry, ehFrame, filterEntry);
// Connect all terminators of the filter block to the handler entry.
foreach (var terminator in FindReachableReturnNodes(filterEntry))
{
AddAbnormalEdge(graph, terminator, ehFrame, handlerEntry);
}
}
}
// Obtain dominator info.
var dominatorInfo = new DominatorInfo(graph.Entrypoint);
// Add all handler nodes to the cluster, and add abnormal edges for each try node to the handler start node.
var handlerExits = new Dictionary <EHFrame, ICollection <Node> >();
foreach (var subGraph in graph.SubGraphs.OrderBy(x => x.Nodes.Count))
{
var ehFrame = (EHFrame)subGraph.UserData[EHFrame.EHFrameProperty];
var tryEntry = GetNode(graph, (long)ehFrame.TryStart);
var handlerEntry = GetNode(graph, (long)ehFrame.HandlerAddress);
// Determine the handler exits.
var handlerBody = CollectHandlerNodes(handlerEntry, dominatorInfo.GetDominatedNodes(handlerEntry));
foreach (var handlerNode in handlerBody)
{
subGraph.Nodes.Add(handlerNode);
}
handlerExits.Add(ehFrame, new HashSet <Node>(handlerBody.Where(x => x.OutgoingEdges.Count == 0)));
// Add for each node in the try block an abnormal edge.
var tryBody = new HashSet <Node>(subGraph.Nodes.Except(handlerBody));
foreach (var node in tryBody.Where(n =>
!n.UserData.ContainsKey(ControlFlowGraph.TopMostEHProperty) && n != tryEntry))
{
AddAbnormalEdge(graph, node, ehFrame, handlerEntry);
}
// Register EH boundaries in the sub graph.
subGraph.UserData[ControlFlowGraph.TryBlockProperty] = tryBody;
subGraph.UserData[ControlFlowGraph.HandlerBlockProperty] = handlerBody;
if (ehFrame.Type == EHType.FILTER)
{
var filterEntry = GetNode(graph, (long)ehFrame.FilterAddress);
subGraph.UserData[ControlFlowGraph.FilterStartProperty] = filterEntry;
}
}
// Since a LEAVE instruction might not directly transfer control to the referenced instruction,
// but rather transfer control to a finally block first, we have to add edges to these nodes
// as well.
foreach (var node in graph.Nodes)
{
if (node.SubGraphs.Count > 0)
{
// Check if the node ends with a LEAVE.
var block = GetUserData <ILBasicBlock>(node, ILBasicBlock.BasicBlockProperty);
if (block == null)
{
continue;
}
var last = block.Instructions[block.Instructions.Count - 1];
if (last.OpCode.Code == ILCode.LEAVE)
{
// Find the frame we're jumping out of.
var ehFrame = last.ProgramState.EHStack.Peek();
// Add for each handler exit an edge to the referenced instruction.
foreach (var exit in handlerExits[ehFrame])
{
var edge = CreateEdge(exit, node.OutgoingEdges.First().Target, ControlFlowGraph.EndFinallyConditionLabel);
exit.UserData[ControlFlowGraph.TopMostEHProperty] = ehFrame;
graph.Edges.Add(edge);
}
}
}
}
}
public void ComplexLoopTest()
{
var reader = new DotReader(new StringReader(@"
strict digraph {
1 -> 2 -> 3 -> 4 -> 3 -> 5 -> 6 -> 7
}"));
var cfg = reader.Read();
var info = new DominatorInfo(cfg.Nodes["1"]);
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["1"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["4"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["5"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["1"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["2"], cfg.Nodes["1"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["4"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["5"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["2"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["3"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["3"], cfg.Nodes["2"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["4"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["5"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["3"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["2"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["3"]));
Assert.True(info.Dominates(cfg.Nodes["4"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["5"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["6"]));
Assert.False(info.Dominates(cfg.Nodes["4"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["5"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["5"], cfg.Nodes["2"]));
Assert.False(info.Dominates(cfg.Nodes["5"], cfg.Nodes["3"]));
Assert.False(info.Dominates(cfg.Nodes["5"], cfg.Nodes["4"]));
Assert.True(info.Dominates(cfg.Nodes["5"], cfg.Nodes["5"]));
Assert.True(info.Dominates(cfg.Nodes["5"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["5"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["6"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["6"], cfg.Nodes["2"]));
Assert.False(info.Dominates(cfg.Nodes["6"], cfg.Nodes["3"]));
Assert.False(info.Dominates(cfg.Nodes["6"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["6"], cfg.Nodes["5"]));
Assert.True(info.Dominates(cfg.Nodes["6"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["6"], cfg.Nodes["7"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["1"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["2"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["3"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["4"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["5"]));
Assert.False(info.Dominates(cfg.Nodes["7"], cfg.Nodes["6"]));
Assert.True(info.Dominates(cfg.Nodes["7"], cfg.Nodes["7"]));
}
