private T GetEnvironment <T>(ISymbol symbol,
SyntaxNode node,
Dictionary <ISymbol, T> permanentEnvironments,
Dictionary <SyntaxNode, T> temporaryEnvironments)
{
if (permanentEnvironments.TryGetValue(symbol, out var env))
{
return(env);
}
if (temporaryEnvironments.TryGetValue(node, out env))
{
return(env);
}
// external symbol or class member, assume defaults
env = (T)Activator.CreateInstance(typeof(T), AreDefaultsSecure, SecurityDiagnosticHelpers.GetTypeSymbol(symbol), node);
permanentEnvironments[symbol] = env;
return(env);
}