Add proper static initialization

tests/integration_test.rs

@@ -154,7 +154,6 @@ fn should_do_class_static_initialization() {
     assert_eq!(257, get_int(last_frame_value))
 }
 
-#[ignore]
 #[test]
 fn should_do_class_static_initialization_multiple_classes() {
     let vm = VM::new(

vm/src/execution_engine/engine.rs

@@ -1,3 +1,4 @@
+use std::collections::HashSet;
 use crate::error::Error;
 use crate::execution_engine::opcode::*;
 use crate::heap::heap::Heap;
@@ -20,6 +21,7 @@ impl<'a> Engine<'a> {
         let mut stack_frames = vec![method.new_stack_frame()];
         let mut last_value: Option<Vec<i32>> = None;
         let mut current_class_name: String;
+        let mut static_set: HashSet<String> = HashSet::new();
 
         while !stack_frames.is_empty() {
             let stack_frame = stack_frames
@@ -688,6 +690,20 @@ impl<'a> Engine<'a> {
                             fieldref_constpool_index,
                         )?;
 
+                    //todo!!
+                    //try call invoke static `"<clinit>:()V"` on `class_name` (it should be done only once)
+                    if !static_set.contains(class_name.as_str()) {
+                        static_set.insert(class_name.clone());
+                        if let Ok(clinit) = self.method_area.get_method_by_name_signature(class_name.as_str(), "<clinit>:()V") {
+                            stack_frame.advance_pc(-2);
+                            let next_frame = clinit.new_stack_frame();
+                            //stack_frame.incr_pc(); //incr here because of borrowing problem
+                            stack_frames.push(next_frame);
+                            println!("!!!invoke -> {class_name}.<clinit>:()V");
+                            continue;
+                        }
+                    }
+
                     let field = self
                         .method_area
                         .loaded_classes

vm/src/vm.rs

@@ -20,15 +20,6 @@ impl VM {
 
         let mut engine = Engine::new(&self.class_loader.method_area());
 
-        for (class_name, java_class) in self.class_loader.method_area().loaded_classes.iter() {
-            if let Some(java_method) = java_class.methods.method_by_signature.get("<clinit>:()V") {
-                println!(
-                    "About to initialize java class {class_name} java_method={java_method:?}"
-                );
-                engine.execute(java_method)?; //todo implement multiclass correct initialization order
-            }
-        }
-
         engine.execute(main_method)
     }
 }