Use bootstrap classloader to only provide access to JRE classes

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/ClasspathHelper.java

@@ -30,7 +30,8 @@ public class ClasspathHelper {
 
   private static Method findMethodOnClasspath(String targetClass, String methodSignature) {
     try {
-      Class cls = Class.forName(targetClass);
+      // use bootstrap classloader to only provide access to JRE classes
+      Class cls = new ClassLoader(null) {}.loadClass(targetClass);
       for (Method mtd : cls.getMethods()) {
         // use contains() to ignore access modifiers and thrown exceptions
         if (mtd.toString().contains(methodSignature)) {

plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/exps/InvocationExprent.java

@@ -394,6 +394,8 @@ public class InvocationExprent extends Exprent {
       }
     }
     else {
+      // TODO: tap into IDEA indices to access libraries methods details
+
       // try to check the class on the classpath
       Method mtd = ClasspathHelper.findMethod(classname, name, descriptor);
       return mtd != null && mtd.isVarArgs();