Add stubs for jdk.internal.misc.Unsafe

tests/integration_test.rs

@@ -394,6 +394,15 @@ fn should_do_trivial_reflection_with_primitives() {
     assert_eq!(9369, get_int(last_frame_value))
 }
 
+#[test]
+fn should_do_trivial_unsafe_things() {
+    let mut vm = VM::new("std");
+    let last_frame_value = vm
+        .run("samples.jdkinternal.unsafe.trivial.UnsafeUsage")
+        .unwrap();
+    assert_eq!(1, get_int(last_frame_value))
+}
+
 fn get_int(locals: Option<Vec<i32>>) -> i32 {
     *locals.unwrap().last().unwrap()
 }

tests/test_data/UnsafeUsage.java

@@ -0,0 +1,15 @@
+// javac --add-exports java.base/jdk.internal.misc=ALL-UNNAMED  -d . UnsafeUsage.java
+
+package samples.jdkinternal.unsafe.trivial;
+
+import jdk.internal.misc.Unsafe;
+
+public class UnsafeUsage {
+
+    public static void main(String[] args) {
+        Unsafe unsafe = Unsafe.getUnsafe();
+
+        int isBigEndian = !unsafe.isBigEndian() ? 1 : 0;
+    }
+
+}

vm/src/execution_engine/system_native_table.rs

@@ -33,6 +33,14 @@ static SYSTEM_NATIVE_TABLE: Lazy<
         "jdk/internal/misc/Unsafe:registerNatives:()V",
         void_stub as fn(&[i32]) -> crate::error::Result<Vec<i32>>,
     );
+    table.insert(
+        "jdk/internal/misc/Unsafe:arrayBaseOffset0:(Ljava/lang/Class;)I",
+        int_stub as fn(&[i32]) -> crate::error::Result<Vec<i32>>,
+    );
+    table.insert(
+        "jdk/internal/misc/Unsafe:arrayIndexScale0:(Ljava/lang/Class;)I",
+        int_stub as fn(&[i32]) -> crate::error::Result<Vec<i32>>,
+    );
     table.insert(
         "java/lang/String:intern:()Ljava/lang/String;",
         intern_wrp as fn(&[i32]) -> crate::error::Result<Vec<i32>>,
@@ -61,3 +69,7 @@ fn void_stub(_args: &[i32]) -> crate::error::Result<Vec<i32>> {
 fn bool_stub(_args: &[i32]) -> crate::error::Result<Vec<i32>> {
     Ok(vec![false as i32])
 }
+
+fn int_stub(_args: &[i32]) -> crate::error::Result<Vec<i32>> {
+    Ok(vec![0])
+}

vm/src/method_area/method_area.rs

@@ -365,15 +365,34 @@ impl MethodArea {
     }
 
     fn generate_synthetic_classes() -> HashMap<String, Arc<JavaClass>> {
-        ["I", "J", "F", "D", "B", "C", "S", "Z", "V"]
-            .into_iter()
-            .map(|class_name| {
-                (
-                    class_name.to_string(),
-                    Self::generate_synthetic_class(class_name),
-                )
-            })
-            .collect()
+        [
+            "I",
+            "J",
+            "F",
+            "D",
+            "B",
+            "C",
+            "S",
+            "Z",
+            "V",
+            "[I",
+            "[J",
+            "[F",
+            "[D",
+            "[B",
+            "[C",
+            "[S",
+            "[Z", //todo implement real Classes for arrays
+            "[Ljava/lang/Object;",
+        ] //todo implement real Classes for array of objects
+        .into_iter()
+        .map(|class_name| {
+            (
+                class_name.to_string(),
+                Self::generate_synthetic_class(class_name),
+            )
+        })
+        .collect()
     }
 
     fn generate_synthetic_class(class_name: &str) -> Arc<JavaClass> {