private static SyntaxTree ComputeSyntaxTree(CSharpSyntaxNode node)
{
ArrayBuilder <CSharpSyntaxNode> nodes = null;
SyntaxTree tree = null;
// Find the nearest parent with a non-null syntax tree
while (true)
{
tree = node._syntaxTree;
if (tree != null)
{
break;
}
var parent = node.Parent;
if (parent == null)
{
// set the tree on the root node atomically
Interlocked.CompareExchange(ref node._syntaxTree, CSharpSyntaxTree.CreateWithoutClone(node), null);
tree = node._syntaxTree;
break;
}
tree = parent._syntaxTree;
if (tree != null)
{
node._syntaxTree = tree;
break;
}
(nodes ?? (nodes = ArrayBuilder <CSharpSyntaxNode> .GetInstance())).Add(node);
node = parent;
}
// Propagate the syntax tree downwards if necessary
if (nodes != null)
{
Debug.Assert(tree != null);
foreach (var n in nodes)
{
var existingTree = n._syntaxTree;
if (existingTree != null)
{
Debug.Assert(existingTree == tree, "how could this node belong to a different tree?");
// yield the race
break;
}
n._syntaxTree = tree;
}
nodes.Free();
}
return(tree);
}
private static void ComputeSyntaxTree(CSharpSyntaxNode node)
{
ArrayBuilder <CSharpSyntaxNode> nodes = null;
SyntaxTree tree = null;
// Find the nearest parent with a non-null syntax tree
while (true)
{
tree = node._syntaxTree;
if (tree != null)
{
break;
}
var parent = node.Parent;
if (parent == null)
{
Interlocked.CompareExchange(ref node._syntaxTree, CSharpSyntaxTree.CreateWithoutClone(node), null);
tree = node._syntaxTree;
break;
}
else if (parent._syntaxTree != null)
{
Interlocked.CompareExchange(ref node._syntaxTree, parent._syntaxTree, null);
tree = node._syntaxTree;
break;
}
else
{
(nodes ?? (nodes = ArrayBuilder <CSharpSyntaxNode> .GetInstance())).Add(node);
node = parent;
}
}
// Propagate the syntax tree downwards if necessary
if (nodes != null)
{
Debug.Assert(tree != null);
foreach (var n in nodes)
{
var existingTree = Interlocked.CompareExchange(ref n._syntaxTree, tree, null);
if (existingTree != null)
{
tree = existingTree;
}
}
nodes.Free();
}
}