public void Convert()
{
MethodRoot.Start = ConvertNode(MethodRoot.Start);
var graphNodes = MethodRoot.Start.IterateGraphNodesRecursive(false).ToArray();
foreach (var graphNode in graphNodes)
{
ConvertNode(graphNode);
}
GraphNode ConvertNode(GraphNode graphNode)
{
return(graphNode switch
{
null => throw new ArgumentOutOfRangeException(nameof(graphNode)),
GraphDataFlowBlockNode _ => graphNode,
GraphDataFlowExpressionNode _ => graphNode,
GraphControlFlowBlockNode blockNode => ConvertControlFlowNode(blockNode),
GraphControlFlowConditionalNode conditionalNode => ConvertControlFlowNode(conditionalNode),
GraphControlFlowReturnNode returnNode => ConvertControlFlowNode(returnNode),
GraphDataFlowConditionalNode _ => graphNode,
GraphDataFlowReturnNode _ => graphNode,
_ => throw new ArgumentOutOfRangeException(nameof(graphNode))
});
}
private bool SimplifyGraph(GraphMethodRoot methodNode)
{
var oldStart = methodNode.Start;
var res = SimplifyNode(oldStart);
if (res)
{
if (oldStart is GraphControlFlowBlockNode oldStartBlockNode)
{
methodNode.Start = oldStartBlockNode.Outgoing;
Log.Verbose(
"CFG: {MethodName}: simplified away start point {Node}, new start point is {NewNode}",
methodNode.Name,
oldStart,
methodNode.Start
);
}
else
{
Log.Error(
"CFG: {MethodName}: simplified away start point {Node}, but it wasn't {TypeName}",
methodNode.Name,
oldStart,
nameof(GraphControlFlowBlockNode)
);
}
}
var graphNodes = methodNode.Start.IterateGraphNodesRecursive(false).ToArray();
foreach (var graphNode in graphNodes)
{
res = SimplifyNode(graphNode) || res;
}
return(res);
bool SimplifyNode(GraphNode graphNode)
{
return(graphNode switch
{
null => throw new ArgumentOutOfRangeException(nameof(graphNode)),
GraphControlFlowBlockNode blockNode => SimplifyGraph(blockNode),
GraphControlFlowConditionalNode _ => false,
GraphControlFlowReturnNode _ => false,
_ => throw new ArgumentOutOfRangeException(nameof(graphNode))
});
}
AddStatementToGraphNode(StatementBase statement,
GraphMethodRoot methodRoot,
GraphControlFlowBlockNode target,
GraphNode continueTarget,
GraphNode breakTarget)
{
switch (statement)
{
case ContinueStatement _:
target.Outgoing = continueTarget;
return(Array.Empty <GraphNode>(), null);
case ForIterationStatement forStatement:
{
var processConditional = ProcessConditional(forStatement);
if (!processConditional.HasValue)
{
return(Array.Empty <GraphNode>(), target);
}
var(conditionalStartNode, conditionalNode) = processConditional.Value;
var preemptiveExits = new List <GraphNode>();
// block inside FOR that contains incrementors and stuff
var iterationExpressionBlock = new GraphControlFlowBlockNode(methodRoot);
// block after FOR
var nextBlock = new GraphControlFlowBlockNode(methodRoot);
{
foreach (var expression in forStatement.IterationExpression)
{
iterationExpressionBlock.Body.Add(
new GraphControlFlowExpressionNode(methodRoot, expression)
);
}
iterationExpressionBlock.Outgoing = conditionalStartNode;
}
{
var trueBlock = new GraphControlFlowBlockNode(methodRoot);
conditionalNode.TrueOutgoing = trueBlock;
var(truePreemptiveExits, trueNext) = AddStatementToGraphNode(forStatement.Block,
methodRoot,
trueBlock,
iterationExpressionBlock,
nextBlock);
preemptiveExits.AddRange(truePreemptiveExits);
if (trueNext != null)
{
trueNext.Outgoing = iterationExpressionBlock;
}
}
conditionalNode.FalseOutgoing = nextBlock;
return(preemptiveExits.ToArray(), nextBlock);
}
case IfStatement ifStatement:
{
var processConditional = ProcessConditional(ifStatement);
if (!processConditional.HasValue)
{
return(Array.Empty <GraphNode>(), target);
}
var(_, conditionalNode) = processConditional.Value;
var preemptiveExits = new List <GraphNode>();
// block after IF
var nextBlock = new GraphControlFlowBlockNode(methodRoot);
{
var trueBlock = new GraphControlFlowBlockNode(methodRoot);
conditionalNode.TrueOutgoing = trueBlock;
var(truePreemptiveExits, trueNext) = AddStatementToGraphNode(ifStatement.Block,
methodRoot,
trueBlock,
continueTarget,
breakTarget);
preemptiveExits.AddRange(truePreemptiveExits);
if (trueNext != null)
{
trueNext.Outgoing = nextBlock;
}
}
if (ifStatement.ElseBlock != null)
{
var falseBlock = new GraphControlFlowBlockNode(methodRoot);
conditionalNode.FalseOutgoing = falseBlock;
var(falsePreemptiveExits, falseNext) = AddStatementToGraphNode(ifStatement.ElseBlock,
methodRoot,
falseBlock,
continueTarget,
breakTarget);
preemptiveExits.AddRange(falsePreemptiveExits);
if (falseNext != null)
{
falseNext.Outgoing = nextBlock;
}
}
else
{
conditionalNode.FalseOutgoing = nextBlock;
}
return(preemptiveExits.ToArray(), nextBlock);
}
case ReturnStatement returnStatement:
{
var graphReturnNode = new GraphControlFlowReturnNode(
methodRoot,
(ExpressionBase)returnStatement.What,
false
);
target.Outgoing = graphReturnNode;
return(new GraphNode[] { graphReturnNode }, null);
}
case SimpleCompoundStatement simpleCompoundStatement:
{
var preemptiveExits = new List <GraphNode>();
var currentTarget = target;
foreach (var statementBase in simpleCompoundStatement.Body)
{
var(newPreemptiveExits, newNext) = AddStatementToGraphNode(statementBase,
methodRoot,
currentTarget,
continueTarget,
breakTarget);
preemptiveExits.AddRange(newPreemptiveExits);
currentTarget = newNext;
}
if (currentTarget != null)
{
var newBlockNode = new GraphControlFlowBlockNode(methodRoot);
currentTarget.Outgoing = newBlockNode;
currentTarget = newBlockNode;
}
return(preemptiveExits.ToArray(), currentTarget);
}
case SimpleDeclarationStatement _:
return(Array.Empty <GraphNode>(), target);
case SimpleExpressionStatement simpleExpressionStatement:
{
var node = new GraphControlFlowExpressionNode(methodRoot, simpleExpressionStatement.Expression);
target.Body.Add(node);
return(Array.Empty <GraphNode>(), target);
}
case WhileIterationStatement whileStatement:
{
var processConditional = ProcessConditional(whileStatement);
if (!processConditional.HasValue)
{
return(Array.Empty <GraphNode>(), target);
}
var(conditionalStartNode, conditionalNode) = processConditional.Value;
var preemptiveExits = new List <GraphNode>();
// block after WHILE
var nextBlock = new GraphControlFlowBlockNode(methodRoot);
{
var trueBlock = new GraphControlFlowBlockNode(methodRoot);
conditionalNode.TrueOutgoing = trueBlock;
var(truePreemptiveExits, trueNext) = AddStatementToGraphNode(whileStatement.Block,
methodRoot,
trueBlock,
conditionalStartNode,
nextBlock);
preemptiveExits.AddRange(truePreemptiveExits);
if (trueNext != null)
{
trueNext.Outgoing = conditionalStartNode;
}
}
conditionalNode.FalseOutgoing = nextBlock;
return(preemptiveExits.ToArray(), nextBlock);
}
case SimpleSelectionStatement _:
goto default;
default:
throw new ArgumentOutOfRangeException(nameof(statement));
}
(GraphNode conditionalStartNode, GraphControlFlowConditionalNode conditionalNode)?
ProcessConditional(SimpleSelectionStatement statement)
{
GraphControlFlowConditionalNode conditionalNode;
if (statement.Condition.Count >= 1)
{
conditionalNode = new GraphControlFlowConditionalNode(methodRoot, statement.Condition[^ 1]);
