// Parse a string specifying a list of assemblies and types
// containing a startup hook, and call each hook in turn.
private static void ProcessStartupHooks()
{
// Initialize tracing before any user code can be called.
System.Diagnostics.Tracing.RuntimeEventSource.Initialize();
string?startupHooksVariable = (string?)AppContext.GetData("STARTUP_HOOKS");
if (startupHooksVariable == null)
{
return;
}
char[] disallowedSimpleAssemblyNameChars = new char[]
{
Path.DirectorySeparatorChar,
Path.AltDirectorySeparatorChar,
' ',
','
};
// Parse startup hooks variable
string[] startupHookParts = startupHooksVariable.Split(Path.PathSeparator);
StartupHookNameOrPath[] startupHooks = new StartupHookNameOrPath[startupHookParts.Length];
for (int i = 0; i < startupHookParts.Length; i++)
{
string startupHookPart = startupHookParts[i];
if (string.IsNullOrEmpty(startupHookPart))
{
// Leave the slot in startupHooks empty (nulls for everything). This is simpler than shifting and resizing the array.
continue;
}
if (Path.IsPathFullyQualified(startupHookPart))
{
startupHooks[i].Path = startupHookPart;
}
else
{
// The intent here is to only support simple assembly names, but AssemblyName .ctor accepts
// lot of other forms (fully qualified assembly name, strings which look like relative paths and so on).
// So add a check on top which will disallow any directory separator, space or comma in the assembly name.
for (int j = 0; j < disallowedSimpleAssemblyNameChars.Length; j++)
{
if (startupHookPart.Contains(disallowedSimpleAssemblyNameChars[j]))
{
throw new ArgumentException(SR.Format(SR.Argument_InvalidStartupHookSimpleAssemblyName, startupHookPart));
}
}
if (startupHookPart.EndsWith(DisallowedSimpleAssemblyNameSuffix, StringComparison.OrdinalIgnoreCase))
{
throw new ArgumentException(SR.Format(SR.Argument_InvalidStartupHookSimpleAssemblyName, startupHookPart));
}
try
{
// This will throw if the string is not a valid assembly name.
startupHooks[i].AssemblyName = new AssemblyName(startupHookPart);
}
catch (Exception assemblyNameException)
{
throw new ArgumentException(SR.Format(SR.Argument_InvalidStartupHookSimpleAssemblyName, startupHookPart), assemblyNameException);
}
}
}
// Call each hook in turn
foreach (StartupHookNameOrPath startupHook in startupHooks)
{
CallStartupHook(startupHook);
}
}
public object GetData(string name) => AppContext.GetData(name);