private CFGNode ProcessCFGNode(
CFGNode calleeNode, CFGNode callerNode,
CFGNode callerSuccessorNode,
IExpression thisReplacement,
IExpression returnValueTarget,
MethodCompileInfo calleeMethodCompileInfo,
MethodCompileInfo callerMethodCompileInfo,
Dictionary<string, VariableDefinition> renamedLocalsMap,
Dictionary<string, VariableReference> variableReplacements,
Dictionary<string, IExpression> argumentReplacements,
Dictionary<CFGNode, CFGNode> processedNodes,
CFGNodeSet newNodes
)
{
CFGNode inlinedNode;
if (processedNodes.TryGetValue(calleeNode, out inlinedNode))
{
// we've already seen this node
// don't inline it again otherwise we'll end up in an infinite recursion
return inlinedNode;
}
CFG cfg = callerNode.Graph;
inlinedNode = cfg.AddNode();
inlinedNode.FlowControl = calleeNode.FlowControl;
inlinedNode.BasicBlock = CodeUtility.CloneCode<BasicBlock>(calleeNode.BasicBlock);
processedNodes[calleeNode] = inlinedNode;
newNodes.Add(inlinedNode);
Debug.Assert(
inlinedNode.BasicBlock.Statements.Count == calleeNode.BasicBlock.Statements.Count,
string.Format("Clone code produced {0} statements instead of {1}", inlinedNode.BasicBlock.Statements.Count, calleeNode.BasicBlock.Statements.Count)
);
// rename all variables in callee so they don't clash with variables in caller
CodeUtility.MatchAndReplaceCode<IVariableReferenceExpression>(
inlinedNode.BasicBlock,
delegate(IVariableReferenceExpression expression)
{
return true;
},
delegate(IVariableReferenceExpression expression)
{
VariableReference variableReplacement;
if (!variableReplacements.TryGetValue(expression.Variable.Name, out variableReplacement))
{
if (callerMethodCompileInfo.IsTemporary(expression.Variable))
{
variableReplacement = callerMethodCompileInfo.NewTemporary(expression.Variable.VariableType);
}
else if (callerMethodCompileInfo.IsFrozen(expression.Variable))
{
variableReplacement = callerMethodCompileInfo.NewFrozen(expression.Variable.VariableType);
}
else
{
VariableDefinition variableDefinition;
if (!renamedLocalsMap.TryGetValue(expression.Variable.Name, out variableDefinition))
{
int index = callerMethodCompileInfo.Method.Body.Variables.Count;
string name = "V_" + index; // TODO: Extract into constant and helper method
TypeReference type = expression.Variable.VariableType;
variableDefinition = new VariableDefinition(name, index, callerMethodCompileInfo.Method, type);
callerMethodCompileInfo.Method.Body.Variables.Add(variableDefinition);
renamedLocalsMap[expression.Variable.Name] = variableDefinition;
}
variableReplacement = variableDefinition;
}
variableReplacements[expression.Variable.Name] = variableReplacement;
}
expression.Variable = variableReplacement;
return expression;
},
true
);
// replace all instances of "this" in callee with the target object
if (thisReplacement != null)
{
CodeUtility.MatchAndReplaceCode<IExpression>(
inlinedNode.BasicBlock,
delegate(IExpression expression)
{
return expression is IThisReferenceExpression;
},
delegate(IExpression expression)
{
return thisReplacement;
},
true
);
}
// replace all arguments references
if (argumentReplacements != null)
{
CodeUtility.MatchAndReplaceCode<IExpression>(
inlinedNode.BasicBlock,
delegate(IExpression expression)
{
return expression is IArgumentReferenceExpression;
},
delegate(IExpression expression)
{
IArgumentReferenceExpression argumentReferenceExpression = (IArgumentReferenceExpression)expression;
IExpression replacementExpression;
if (!argumentReplacements.TryGetValue(argumentReferenceExpression.Parameter.Name, out replacementExpression))
{
throw new CompilerException(
string.Format(
"Error while inlining call to {0}. Could not find argument replacement for parameter \"{1}\". Parameter sequence is {2}.",
calleeMethodCompileInfo.Method,
argumentReferenceExpression.Parameter.Name,
argumentReferenceExpression.Parameter.Sequence
)
);
}
else
{
return replacementExpression;
}
},
true
);
}
if (inlinedNode.FlowControl == FlowControl.Throw)
{
// TODO: fixup exception handling info
throw new CannotInlineMethodException("Contain throw statement");
}
else if (inlinedNode.FlowControl == FlowControl.ConditionalBranch)
{
// TODO: Fix this so that conditioanl branches can be inlined
throw new CannotInlineMethodException("Contains a conditional branch");
}
else if (inlinedNode.FlowControl == FlowControl.Return)
{
// replace return statement with assignment to variable being assigned to in caller
Debug.Assert(inlinedNode.BasicBlock.Statements.Count == 1, string.Format("Return basic block has {0} statements", inlinedNode.BasicBlock.Statements.Count));
Debug.Assert(inlinedNode.BasicBlock.Statements[0] is IMethodReturnStatement);
IMethodReturnStatement methodReturnStatement = (IMethodReturnStatement)inlinedNode.BasicBlock.Statements[0];
inlinedNode.BasicBlock.Statements.Clear();
inlinedNode.BasicBlock.Statements.Add(new AssignStatement(returnValueTarget, methodReturnStatement.Expression));
// add edge between this return node and the caller node's successor
Debug.Assert(inlinedNode.SuccessorCount == 0);
Debug.Assert(callerSuccessorNode != null);
cfg.AddEdge(inlinedNode, callerSuccessorNode);
// flow control is no longer return
inlinedNode.FlowControl = FlowControl.Next;
}
foreach (CFGEdge outEdge in calleeNode.Graph.OutEdges(calleeNode))
{
CFGNode newSuccessorNode = ProcessCFGNode(
outEdge.Target, callerNode, callerSuccessorNode,
thisReplacement, returnValueTarget,
calleeMethodCompileInfo, callerMethodCompileInfo,
renamedLocalsMap,
variableReplacements,
argumentReplacements,
processedNodes,
newNodes
);
cfg.AddEdge(inlinedNode, newSuccessorNode, outEdge.BranchCondition);
}
return inlinedNode;
}
public override bool Transform(MethodCompileInfo callerMethodCompileInfo)
{
List<CFGNode> callerNodes = new List<CFGNode>();
foreach (CFGNode node in callerMethodCompileInfo.CFG.Vertices)
{
callerNodes.Add(node);
}
foreach (CFGNode callerNode in callerNodes)
{
BasicBlock bb = callerNode.BasicBlock;
// TODO: For now assume that the only statement is an assignstatement
if (bb.Statements.Count != 1)
{
continue;
}
IAssignStatement assignStatement = bb.Statements[0] as IAssignStatement;
if (assignStatement == null)
{
continue;
}
IMethodInvokeExpression methodInvokeExpression = assignStatement.Expression as IMethodInvokeExpression;
if (methodInvokeExpression == null)
{
continue;
}
IMethodReferenceExpression methodReferenceExpression = methodInvokeExpression.Method as IMethodReferenceExpression;
if (methodReferenceExpression == null)
{
continue;
}
MethodDefinition methodDefinition;
if (!ReferenceResolver.TryResolveMethodReference(methodReferenceExpression.Method, callerMethodCompileInfo.AssemblyCompileInfo.Assembly.Resolver, out methodDefinition))
{
continue;
}
MethodCompileInfo calleeMethodCompileInfo;
if (!callerMethodCompileInfo.AssemblyCompileInfo.MethodCompileInfos.TryGetValue(methodDefinition, out calleeMethodCompileInfo))
{
continue;
}
if (callerNode.FlowControl != FlowControl.Call)
{
continue;
}
if (!CanBeInlined(calleeMethodCompileInfo, callerMethodCompileInfo))
{
continue;
}
// graft the callee CFG into the caller CFG
Debug.Assert(callerNode.SuccessorCount == 1);
CFGNode successorNode = callerNode.Successors[0]; // TODO: Write GetOnlySuccessor() method
CFGNode newCallerNode = callerNode.Graph.AddNode();
newCallerNode.BasicBlock.Statements.Add(new NopStatement());
CFGNodeSet newNodes = new CFGNodeSet(newCallerNode.Graph);
newNodes.Add(newCallerNode);
IExpression thisReplacement = calleeMethodCompileInfo.Method.IsStatic ? null : methodReferenceExpression.Target;
Dictionary<string, IExpression> argumentReplacements;
if (methodDefinition.Parameters.Count > 0)
{
argumentReplacements = new Dictionary<string, IExpression>();
foreach (ParameterDefinition parameterDefinition in methodDefinition.Parameters)
{
argumentReplacements[parameterDefinition.Name] = methodInvokeExpression.Arguments[parameterDefinition.Sequence - 1];
}
}
else
{
argumentReplacements = null;
}
try
{
CFGNode calleeNode = ProcessCFGNode(
calleeMethodCompileInfo.CFG.Root, newCallerNode,
successorNode,
thisReplacement, assignStatement.Target,
calleeMethodCompileInfo, callerMethodCompileInfo,
new Dictionary<string, VariableDefinition>(),
new Dictionary<string, VariableReference>(),
argumentReplacements,
new Dictionary<CFGNode, CFGNode>(),
newNodes
);
foreach (CFGEdge inEdge in callerNode.Graph.InEdges(callerNode))
{
callerNode.Graph.AddEdge(inEdge.Source, newCallerNode, inEdge.BranchCondition);
}
newCallerNode.Graph.AddEdge(newCallerNode, calleeNode);
newCallerNode.FlowControl = FlowControl.Next;
callerNode.Graph.RemoveVertex(callerNode);
//Console.WriteLine("Inlined method " + calleeMethodCompileInfo + " in method " + callerMethodCompileInfo);
}
catch (CannotInlineMethodException e)
{
//Console.WriteLine("Cannot inline method " + calleeMethodCompileInfo + " in method " + calleeMethodCompileInfo + ": " + e);
// inlining failed, let's clean up any nodes we created
foreach (CFGNode newNode in newNodes)
{
newNode.Graph.RemoveVertex(newNode);
}
};
}
return true;
}
public override bool Transform(MethodCompileInfo methodCompileInfo)
{
_methodCompileInfo = methodCompileInfo;
CFGNodeSet wholeSet = new CFGNodeSet(_methodCompileInfo.CFG);
List<CFGNode> sortedNodes = new List<CFGNode>();
CFGNodeSet roots = new CFGNodeSet(_methodCompileInfo.CFG.Root);//_compileInfo.Roots;
try {
QuickGraph.Algorithms.TopologicalSortAlgorithm sortAlgorithm = new QuickGraph.Algorithms.TopologicalSortAlgorithm(_methodCompileInfo.CFG);
sortAlgorithm.Compute();
foreach (CFGNode node in sortAlgorithm.SortedVertices)
{
if (!roots.Contains(node))
{
sortedNodes.Add(node);
}
wholeSet.Add(node);
}
}
catch (QuickGraph.Exceptions.NonAcyclicGraphException)
{
foreach (QuickGraph.Concepts.IVertex vertex in _methodCompileInfo.CFG.Vertices)
{
if (!roots.Contains((CFGNode)vertex))
{
sortedNodes.Add((CFGNode)vertex);
}
wholeSet.Add((CFGNode)vertex);
}
}
Dictionary<CFGNode, CFGNodeSet> domMap = _methodCompileInfo.Dominators;
domMap.Clear();
foreach (CFGNode root in roots)
{
// root only dominated by itself
domMap[root] = new CFGNodeSet(root);
}
Dictionary<CFGNode, CFGNode[]> predecessorMap = new Dictionary<CFGNode, CFGNode[]>();
foreach (CFGNode node in sortedNodes)
{
predecessorMap[node] = node.Predecessors;
}
Dictionary<CFGNode, CFGNodeSet> domMapPrime = new Dictionary<CFGNode, CFGNodeSet>();
foreach (KeyValuePair<CFGNode, CFGNodeSet> entry in domMap)
{
domMapPrime.Add(entry.Key, entry.Value.Clone());
}
// initialize to the whole set
foreach (CFGNode node in sortedNodes)
{
domMap[node] = wholeSet;
}
do
{
bool changed = false;
for (int i = 0; i < sortedNodes.Count; i++)
{
CFGNode n = sortedNodes[i];
domMapPrime[n] = domMap[n];
domMap[n] = new CFGNodeSet(n);
if (predecessorMap[n].Length > 0)
{
CFGNode[] predecessors = predecessorMap[n];
CFGNodeSet predDomSet = domMap[predecessors[0]].Clone();
for (int j = 1; j < predecessors.Length; j++)
{
predDomSet = predDomSet & domMap[predecessors[j]];
}
domMap[n] += predDomSet;
}
if (!changed && domMap[n] != domMapPrime[n])
{
changed = true;
}
}
if (changed)
{
continue;
}
} while (!DominatorMapsEquals(domMap, domMapPrime));
// TODO: can we find idom at the same time as we find dominator set?
// find immediate dominators
Dictionary<CFGNode, CFGNode> idomMap = _methodCompileInfo.ImmediateDominator;
for (int i = 0; i < sortedNodes.Count; i++)
{
CFGNode n = sortedNodes[i];
CFGNode immediateDominator = null;
foreach (CFGNode dominator in domMap[n])
{
if (dominator == n)
{
continue;
}
if (immediateDominator == null)
{
immediateDominator = dominator;
}
else
{
if (domMap[dominator].Contains(immediateDominator))
{
immediateDominator = dominator;
}
}
}
idomMap[n] = immediateDominator;
}
// dominator frontier
Dictionary<CFGNode, CFGNodeSet> frontierMap = _methodCompileInfo.DominatorFrontier;
frontierMap.Clear();
for (int i = 0; i < sortedNodes.Count; i++)
{
CFGNode n = sortedNodes[i];
if (predecessorMap[n].Length >= 2)
{
CFGNode immediateDominator = idomMap[n];
foreach (CFGNode predecessor in predecessorMap[n])
{
CFGNode runner = predecessor;
while (runner != immediateDominator && idomMap.ContainsKey(runner))
{
CFGNodeSet frontier;
if (!frontierMap.TryGetValue(runner, out frontier))
{
frontier = new CFGNodeSet(_methodCompileInfo.CFG);
frontierMap[runner] = frontier;
}
frontier.Add(n);
runner = idomMap[runner];
}
}
}
}
return true;
}
