private static void GetDisplayClassVariables(
ArrayBuilder<string> displayClassVariableNamesInOrderBuilder,
Dictionary<string, DisplayClassVariable> displayClassVariablesBuilder,
HashSet<string> parameterNames,
InScopeHoistedLocals inScopeHoistedLocals,
DisplayClassInstanceAndFields instance,
HashSet<string> hoistedParameterNames)
{
// Display class instance. The display class fields are variables.
foreach (var member in instance.Type.GetMembers())
{
if (member.Kind != SymbolKind.Field)
{
continue;
}
var field = (FieldSymbol)member;
var fieldName = field.Name;
REPARSE:
DisplayClassVariableKind variableKind;
string variableName;
GeneratedNameKind fieldKind;
int openBracketOffset;
int closeBracketOffset;
GeneratedNames.TryParseGeneratedName(fieldName, out fieldKind, out openBracketOffset, out closeBracketOffset);
switch (fieldKind)
{
case GeneratedNameKind.AnonymousTypeField:
Debug.Assert(fieldName == field.Name); // This only happens once.
fieldName = fieldName.Substring(openBracketOffset + 1, closeBracketOffset - openBracketOffset - 1);
goto REPARSE;
case GeneratedNameKind.TransparentIdentifier:
// A transparent identifier (field) in an anonymous type synthesized for a transparent identifier.
Debug.Assert(!field.IsStatic);
continue;
case GeneratedNameKind.DisplayClassLocalOrField:
// A local that is itself a display class instance.
Debug.Assert(!field.IsStatic);
continue;
case GeneratedNameKind.HoistedLocalField:
// Filter out hoisted locals that are known to be out-of-scope at the current IL offset.
// Hoisted locals with invalid indices will be included since more information is better
// than less in error scenarios.
if (!inScopeHoistedLocals.IsInScope(fieldName))
{
continue;
}
variableName = fieldName.Substring(openBracketOffset + 1, closeBracketOffset - openBracketOffset - 1);
variableKind = DisplayClassVariableKind.Local;
Debug.Assert(!field.IsStatic);
break;
case GeneratedNameKind.ThisProxyField:
// A reference to "this".
variableName = fieldName;
variableKind = DisplayClassVariableKind.This;
Debug.Assert(!field.IsStatic);
break;
case GeneratedNameKind.None:
// A reference to a parameter or local.
variableName = fieldName;
if (parameterNames.Contains(variableName))
{
variableKind = DisplayClassVariableKind.Parameter;
hoistedParameterNames.Add(variableName);
}
else
{
variableKind = DisplayClassVariableKind.Local;
}
Debug.Assert(!field.IsStatic);
break;
default:
continue;
}
if (displayClassVariablesBuilder.ContainsKey(variableName))
{
// Only expecting duplicates for async state machine
// fields (that should be at the top-level).
Debug.Assert(displayClassVariablesBuilder[variableName].DisplayClassFields.Count() == 1);
Debug.Assert(instance.Fields.Count() >= 1); // greater depth
Debug.Assert((variableKind == DisplayClassVariableKind.Parameter) ||
(variableKind == DisplayClassVariableKind.This));
}
else if (variableKind != DisplayClassVariableKind.This || GeneratedNames.GetKind(instance.Type.ContainingType.Name) != GeneratedNameKind.LambdaDisplayClass)
{
// In async lambdas, the hoisted "this" field in the state machine type will point to the display class instance, if there is one.
// In such cases, we want to add the display class "this" to the map instead (or nothing, if it lacks one).
displayClassVariableNamesInOrderBuilder.Add(variableName);
displayClassVariablesBuilder.Add(variableName, instance.ToVariable(variableName, variableKind, field));
}
}
}