lib 1400533 // ECJ

import javax.tools.Diagnostic;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaFileObject;
import org.eclipse.jdt.internal.compiler.tool.EclipseCompilerImpl;

static L<Diagnostic<? extends JavaFileObject>> invokeEcj_direct_withDiagnostics(File optionsFile) ctex {
  new StringWriter writer;
  PrintWriter printWriter = new(writer);
  
  S[] args = { "@" + optionsFile.getPath() };
  
  EclipseCompilerImpl compiler = new EclipseCompilerImpl(printWriter, printWriter, false);
  DiagnosticCollector<JavaFileObject> diagnosticCollector = new DiagnosticCollector<>();
  compiler.diagnosticListener = diagnosticCollector;
  compiler.compile(args);
  L<Diagnostic<? extends JavaFileObject>> diagnostics = diagnosticCollector.getDiagnostics();
  ret diagnostics;
}

Began life as a copy of #1033527