avm1: Add super basic 'ASnative' implementation

Author: Dinnerbone

core/src/avm1/globals.rs

@@ -1,5 +1,6 @@
 use crate::avm1::activation::Activation;
 use crate::avm1::error::Error;
+use crate::avm1::function::NativeFunction;
 use crate::avm1::property::Attribute;
 use crate::avm1::property_decl::{DeclContext, Declaration};
 use crate::avm1::{Object, Value};
@@ -11,6 +12,7 @@ use std::str;
 mod accessibility;
 pub(super) mod array;
 pub(crate) mod as_broadcaster;
+mod asnative;
 pub(crate) mod bevel_filter;
 mod bitmap_data;
 mod bitmap_filter;
@@ -71,6 +73,7 @@ const GLOBAL_DECLS: &[Declaration] = declare_properties! {
     "parseInt" => method(parse_int; DONT_ENUM);
     "parseFloat" => method(parse_float; DONT_ENUM);
     "ASSetPropFlags" => method(object::as_set_prop_flags; DONT_ENUM);
+    "ASnative" => method(asnative::asnative; DONT_ENUM);
     "clearInterval" => method(clear_interval; DONT_ENUM);
     "setInterval" => method(set_interval; DONT_ENUM);
     "clearTimeout" => method(clear_timeout; DONT_ENUM);
@@ -82,6 +85,17 @@ const GLOBAL_DECLS: &[Declaration] = declare_properties! {
     "Infinity" => property(get_infinity; DONT_ENUM);
 };
 
+pub fn get_native_function(id: u32) -> Option<NativeFunction> {
+    Some(match id {
+        0 => escape,
+        1 => unescape,
+        2 => parse_int,
+        3 => parse_float,
+        4 => trace,
+        _ => return None,
+    })
+}
+
 pub fn trace<'gc>(
     activation: &mut Activation<'_, 'gc>,
     _this: Object<'gc>,

core/src/avm1/globals/asnative.rs

@@ -0,0 +1,41 @@
+use crate::avm1::activation::Activation;
+use crate::avm1::error::Error;
+use crate::avm1::function::{FunctionObject, NativeFunction};
+use crate::avm1::{Object, Value};
+
+pub fn asnative<'gc>(
+    activation: &mut Activation<'_, 'gc>,
+    _this: Object<'gc>,
+    args: &[Value<'gc>],
+) -> Result<Value<'gc>, Error<'gc>> {
+    if args.len() != 2 {
+        return Ok(Value::Undefined);
+    }
+    let Ok(category) = args[0].coerce_to_u32(activation) else {
+        return Ok(Value::Undefined);
+    };
+    let Ok(index) = args[1].coerce_to_u32(activation) else {
+        return Ok(Value::Undefined);
+    };
+
+    let category_lookup: Option<fn(u32) -> Option<NativeFunction>> = match category {
+        100 => Some(crate::avm1::globals::get_native_function),
+        101 => Some(crate::avm1::globals::object::get_native_function),
+        _ => None,
+    };
+
+    if let Some(lookup) = category_lookup {
+        let function = lookup(index)
+            .map(FunctionObject::native)
+            .unwrap_or_else(|| FunctionObject::empty());
+        return Ok(function
+            .build(
+                &activation.context.strings,
+                activation.prototypes().function,
+                None,
+            )
+            .into());
+    }
+
+    Ok(Value::Undefined)
+}

core/src/avm1/globals/object.rs

@@ -2,6 +2,7 @@
 
 use crate::avm1::activation::Activation;
 use crate::avm1::error::Error;
+use crate::avm1::function::NativeFunction;
 use crate::avm1::property::Attribute;
 use crate::avm1::property_decl::{DeclContext, Declaration, SystemClass};
 use crate::avm1::{Object, Value};
@@ -24,6 +25,13 @@ const OBJECT_DECLS: &[Declaration] = declare_properties! {
     "registerClass" => method(register_class; DONT_ENUM | DONT_DELETE | READ_ONLY);
 };
 
+pub fn get_native_function(id: u32) -> Option<NativeFunction> {
+    Some(match id {
+        5 => has_own_property,
+        _ => return None,
+    })
+}
+
 /// Constructs the `Object` class.
 ///
 /// Since Object and Function are so heavily intertwined, this function does

tests/tests/swfs/avm1/asnative/output.txt

@@ -0,0 +1,35 @@
+// ASnative(100)
+undefined
+
+// ASnative(100, 0)
+[type Function]
+
+// ASnative(100, "string")
+[type Function]
+
+// ASnative(100, 0, 0)
+undefined
+
+// ASnative("100", "0")
+[type Function]
+
+// ASnative("onehundred", 0)
+undefined
+
+// ASnative(100, {valueOf: function() {return 4;}})("success")
+success
+
+// ASnative(100, 4.5)("success")
+success
+
+// ASnative(100, 0x10000 + 4)("success")
+
+// ASnative(100, 0x100000000 + 4)("success")
+success
+
+// ASnative(100, 0)("&")
+%26
+
+// ASnative(100, 1)("%26")
+&
+

tests/tests/swfs/avm1/asnative/test.fla

@@ -0,0 +1 @@
+num_frames = 1