method invocations!

src/class.rs

@@ -33,9 +33,19 @@ impl Class {
             .get(name)
             .ok_or(anyhow!("Method {} not found", name))
     }
+
+    pub fn get_name(&self) -> &str {
+        if let CpEntry::ClassRef(name_index ) = self.constant_pool.get(&self.this_class).unwrap(){
+            if let CpEntry::Utf8(name) = self.constant_pool.get(name_index).unwrap(){
+                return name;
+            }
+        }
+        panic!();
+    }
 }
 unsafe impl Send for Class {}
 unsafe impl Sync for Class {}
+
 pub struct Method {
     pub(crate) constant_pool: Rc<HashMap<u16, CpEntry>>,
     access_flags: u16,

src/heap.rs

@@ -1,21 +1,47 @@
 use crate::class::{Class, Value};
 use std::collections::HashMap;
+use std::fmt;
 use std::sync::Arc;
+use crate::classloader::CpEntry;
 
-#[derive(Debug)]
 pub struct Object {
     // locked: bool,
     // hashcode: i32,
-    _class: Arc<Class>,
+    pub class: Arc<Class>,
     pub data: HashMap<u16, Arc<Value>>, //TODO optimize
 }
 
 unsafe impl Send for Object {}
+
 unsafe impl Sync for Object {}
 
 impl Object {
-    pub fn new(_class: Arc<Class>, data: HashMap<u16, Arc<Value>>) -> Self {
-        Self { _class, data }
+    pub fn new(class: Arc<Class>, data: HashMap<u16, Arc<Value>>) -> Self {
+        Self { class, data }
+    }
+
+    fn get_field(&self, cp_index: &u16) -> &str {
+        if let CpEntry::Utf8(name) = self.class.constant_pool.get(&cp_index).unwrap() {
+            return name;
+        }
+        panic!()
+    }
+}
+
+impl fmt::Debug for Object {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let fields: Vec<String> = self.data.iter().map(|(k, v)| {
+            let mut r: String = self.get_field(k).into();
+            r.push(':');
+            r.push_str(format!("{:?}", v).as_str());
+            r
+        }
+        ).collect();
+        write!(
+            f,
+            "{} {{ {:?} }}",
+            self.class.get_name(), fields
+        )
     }
 }
 

src/opcodes.rs

@@ -51,6 +51,7 @@ pub const ALOAD_0: &u8 = &42; // (0x2a)
 // pub const bastore:u8 = 84; // (0x54)
 //
 // pub const castore:u8 = 85; // (0x55)
+pub const POP: &u8 = &87; // (0x57) Pop the top operand stack value
 pub const DUP: &u8 = &89; // (0x59) duplicate the top operand stack value
 // pub const dup_x1: u8 = 90; // (0x5a) Duplicate the top operand stack value and insert two values down
 // pub const dup_x2: u8 = 91; // (0x5b) Duplicate the top operand stack value and insert two or three values down

src/vm.rs

@@ -63,9 +63,9 @@ impl Vm {
         println!("get_class {}", class_name);
         let entry = self.classes.entry(class_name.into());
         let entry = entry.or_insert_with(|| {
-            print!("read class {} ", class_name);
+            // print!("read class {} ", class_name);
             let resolved_path = find_class(&self.classpath, class_name).expect("Class not found");
-            println!("full path {}", resolved_path);
+            // println!("full path {}", resolved_path);
             let bytecode = read_bytecode(resolved_path).unwrap();
             Arc::new(load_class(bytecode).unwrap())
         });
@@ -171,26 +171,35 @@ impl Vm {
                             }
                         }
                     }
+                    POP =>{
+                        self.local_stack().pop().expect("Stack empty");
+                    }
                     DUP => {
                         println!("DUP");
                         let value = self.local_stack().pop().expect("Stack empty");
+                        println!("{:?}", value);
                         self.local_stack().push(value.clone());
                         self.local_stack().push(value);
                     }
                     IRETURN => {
+                        println!("return I");
                         return self.local_stack().pop();
                     }
                     DRETURN => {
+                        println!("return D");
                         return self.local_stack().pop();
                     }
                     FRETURN => {
+                        println!("return F");
                         return self.local_stack().pop();
                     }
                     RETURN_VOID => {
+                        println!("return");
                         self.stack.pop();
-                        return Ok(Arc::new(Void))
+                        return Ok(Arc::new(Void));
                     }
                     GETFIELD => {
+                        println!("GETFIELD");
                         let cp_index = read_u16(&code.opcodes, pc);
                         if let CpEntry::Fieldref(_class_index, name_and_type_index) =
                             method.constant_pool.get(&cp_index).unwrap()
@@ -201,7 +210,7 @@ impl Vm {
                                     method.constant_pool.get(name_and_type_index).unwrap()
                                 {
                                     let value = inst.data.get(name).unwrap();
-                                    // println!("{:?}", value);
+                                    println!("{:?}", value);
                                     self.local_stack().push(value.clone());
                                 }
                             }
@@ -209,14 +218,26 @@ impl Vm {
                         pc += 2;
                     }
                     INVOKEVIRTUAL => {
-                        //TODO implement
+                        let cp_index = read_u16(&code.opcodes, pc);
+                        let instance = self.local_stack().pop().unwrap();
+                        if let Some((class, method)) = get_signature_for_invoke(Rc::clone(&method.constant_pool), cp_index) {
+                            let return_value = self.execute(class.as_str(), method.as_str(), Some(instance))?;
+                            if let Void = *return_value {} else { // not let?
+                                self.local_stack().push(return_value);
+                            }
+                        }
+
+                        pc += 2;
                     }
                     INVOKESPECIAL => {
                         println!("INVOKESPECIAL");
                         let cp_index = read_u16(&code.opcodes, pc);
                         let instance = self.local_stack().pop().unwrap();
                         if let Some((class, method)) = get_signature_for_invoke(Rc::clone(&method.constant_pool), cp_index) {
-                            self.execute(class.as_str(), method.as_str(), Some(instance));
+                            let return_value = self.execute(class.as_str(), method.as_str(), Some(instance))?;
+                            if let Void = *return_value {} else { // not let?
+                                self.local_stack().push(return_value);
+                            }
                         }
 
                         pc += 2;

tests/FloatBean.java

@@ -1,7 +1,5 @@
 public class FloatBean {
 
-   private final static float f =42.0F;
-
    private float value;
 
    public float getValue(){