private async Task <Document> InlineTemporaryAsync(Document document, VariableDeclarationSyntax declarator, CancellationToken cancellationToken)
{
var workspace = document.Project.Solution.Workspace;
// Annotate the variable declarator so that we can get back to it later.
var updatedDocument = await document.ReplaceNodeAsync(declarator, declarator.WithAdditionalAnnotations(DefinitionAnnotation), cancellationToken).ConfigureAwait(false);
var semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
var variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
// Create the expression that we're actually going to inline.
var expressionToInline = await CreateExpressionToInlineAsync(variableDeclarator, updatedDocument, cancellationToken).ConfigureAwait(false);
// Collect the identifier names for each reference.
var local = (ILocalSymbol)semanticModel.GetDeclaredSymbol(variableDeclarator, cancellationToken);
var symbolRefs = await SymbolFinder.FindReferencesAsync(local, updatedDocument.Project.Solution, cancellationToken).ConfigureAwait(false);
var references = symbolRefs.Single(r => r.Definition == local).Locations;
var syntaxRoot = await updatedDocument.GetSyntaxRootAsync(cancellationToken).ConfigureAwait(false);
// Collect the topmost parenting expression for each reference.
var nonConflictingIdentifierNodes = references
.Select(loc => (IdentifierNameSyntax)syntaxRoot.FindToken(loc.Location.SourceSpan.Start).Parent)
.Where(ident => !HasConflict(ident, variableDeclarator));
// Add referenceAnnotations to identifier nodes being replaced.
updatedDocument = await updatedDocument.ReplaceNodesAsync(
nonConflictingIdentifierNodes,
(o, n) => n.WithAdditionalAnnotations(ReferenceAnnotation),
cancellationToken).ConfigureAwait(false);
semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
// Get the annotated reference nodes.
nonConflictingIdentifierNodes = await FindReferenceAnnotatedNodesAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
var topmostParentingExpressions = nonConflictingIdentifierNodes
.Select(ident => GetTopMostParentingExpression(ident))
.Distinct();
var originalInitializerSymbolInfo = semanticModel.GetSymbolInfo(variableDeclarator.Initializer.Value, cancellationToken);
// Make each topmost parenting statement or Equals Clause Expressions semantically explicit.
updatedDocument = await updatedDocument.ReplaceNodesAsync(topmostParentingExpressions, (o, n) => Simplifier.Expand(n, semanticModel, workspace, cancellationToken: cancellationToken), cancellationToken).ConfigureAwait(false);
semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
var semanticModelBeforeInline = semanticModel;
variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
var scope = GetScope(variableDeclarator);
var newScope = ReferenceRewriter.Visit(semanticModel, scope, variableDeclarator, expressionToInline, cancellationToken);
updatedDocument = await updatedDocument.ReplaceNodeAsync(scope, newScope, cancellationToken).ConfigureAwait(false);
semanticModel = await updatedDocument.GetSemanticModelAsync(cancellationToken).ConfigureAwait(false);
variableDeclarator = await FindDeclaratorAsync(updatedDocument, cancellationToken).ConfigureAwait(false);
newScope = GetScope(variableDeclarator);
var conflicts = newScope.GetAnnotatedNodesAndTokens(ConflictAnnotation.Kind);
var declaratorConflicts = variableDeclarator.GetAnnotatedNodesAndTokens(ConflictAnnotation.Kind);
// Note that we only remove the local declaration if there weren't any conflicts,
// unless those conflicts are inside the local declaration.
if (conflicts.Count() == declaratorConflicts.Count())
{
// Certain semantic conflicts can be detected only after the reference rewriter has inlined the expression
var newDocument = await DetectSemanticConflicts(updatedDocument,
semanticModel,
semanticModelBeforeInline,
originalInitializerSymbolInfo,
cancellationToken).ConfigureAwait(false);
if (updatedDocument == newDocument)
{
// No semantic conflicts, we can remove the definition.
updatedDocument = await updatedDocument.ReplaceNodeAsync(newScope, RemoveDeclaratorFromScope(variableDeclarator, newScope), cancellationToken).ConfigureAwait(false);
}
else
{
// There were some semantic conflicts, don't remove the definition.
updatedDocument = newDocument;
}
}
return(updatedDocument);
}