fix asm parser for methods

src/main/java/jef/asm/AsmParser.java

@@ -69,7 +69,7 @@ public class AsmParser {
     }
 
     private AsmParseResult parseMethodExpression() throws Exception {
-        var cls = method.getClass();
+        var cls = method.getDeclaringClass();
         var loader = cls.getClassLoader();
         InputStream is = loader.getResourceAsStream(cls.getName().replace(".", "/") + ".class");
         Object[] args = new Object[0];//TODO capturing args here? or maybe not supported since this will only be user by getter evaluation

src/main/java/jef/asm/FilterClassVisitor.java

@@ -10,6 +10,7 @@ class FilterClassVisitor extends ClassVisitor {
     private final String lambdaname;
     private final Object[] args;
 
+    private String className;
     private FilterMethodVisitor mv;
 
     protected FilterClassVisitor(int api, String lambdaname, Object[] args) {
@@ -19,6 +20,12 @@ class FilterClassVisitor extends ClassVisitor {
         this.args = args;
     }
 
+    @Override
+    public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) {
+        super.visit(version, access, name, signature, superName, interfaces);
+        this.className = name;
+    }
+
     @Override
     public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
         if (!name.equals(lambdaname)) {
@@ -28,7 +35,7 @@ class FilterClassVisitor extends ClassVisitor {
         if (mv != null) {
             throw new IllegalStateException("multiple lambda with same name found: " + lambdaname);
         }
-        return mv = new FilterMethodVisitor(api, descriptor, args);
+        return mv = new FilterMethodVisitor(api, className, descriptor, args);
     }
 
     @Override

src/main/java/jef/asm/FilterMethodVisitor.java

@@ -30,7 +30,6 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import java.util.Stack;
-import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
@@ -41,17 +40,22 @@ class FilterMethodVisitor extends MethodVisitor {
     private Expression lambdaExpr;
     private final Set<Field> accessedMembers = new HashSet<>();
 
-    protected FilterMethodVisitor(int api, String descriptor, Object[] args) {
+    protected FilterMethodVisitor(int api, String className, String descriptor, Object[] args) {
         super(api);
-        this.args = args;
 
         //parameters
         var types = Type.getMethodType(descriptor).getArgumentTypes();
+        if (types.length == 0) {// class method //TODO this is dirty, as only works for parameterless class methods
+            this.args = new Object[]{null};
+            parameterClasses = new String[]{className};
+        } else {
+            this.args = args;
             parameterClasses = new String[types.length];
             for (int i = 0; i < types.length; i++) {
                 parameterClasses[i] = types[i].getClassName();
             }
         }
+    }
 
     public AsmParseResult getResult() {
         return new AsmParseResult(lambdaExpr, accessedMembers);