add laziness for math

Author: jasonwilliams

core/engine/src/builtins/mod.rs

@@ -206,7 +206,6 @@ impl Realm {
         AsyncIterator::init(self);
         AsyncFromSyncIterator::init(self);
         ForInIterator::init(self);
-        Math::init(self);
         Json::init(self);
         ArrayIterator::init(self);
         Proxy::init(self);

core/engine/src/context/intrinsics.rs

@@ -6,7 +6,7 @@ use boa_macros::js_str;
 use crate::{
     builtins::{
         function::ConstructorKind, iterable::IteratorPrototypes, uri::UriFunctions, Array, Date,
-        IntrinsicObject, OrdinaryObject,
+        IntrinsicObject, Math, OrdinaryObject,
     },
     js_string,
     native_function::NativeFunctionObject,
@@ -1168,7 +1168,7 @@ impl IntrinsicObjects {
     pub(crate) fn uninit(realm_inner: &WeakGc<RealmInner>) -> Option<Self> {
         Some(Self {
             reflect: JsObject::default(),
-            math: JsObject::default(),
+            math: JsObject::lazy(Math::init, realm_inner),
             json: JsObject::default(),
             throw_type_error: JsFunction::empty_intrinsic_function(false),
             array_prototype_values: JsFunction::empty_intrinsic_function(false),

core/engine/src/object/jsobject.rs

@@ -5,7 +5,8 @@
 use super::{
     internal_methods::{InternalMethodContext, InternalObjectMethods, ORDINARY_INTERNAL_METHODS},
     shape::RootShape,
-    JsPrototype, LazyBuiltIn, LazyPrototype, NativeObject, Object, PrivateName, PropertyMap,
+    BuiltinKind, JsPrototype, LazyBuiltIn, LazyPrototype, NativeObject, Object, PrivateName,
+    PropertyMap,
 };
 use crate::{
     builtins::{
@@ -17,10 +18,11 @@ use crate::{
     error::JsNativeError,
     js_string,
     property::{PropertyDescriptor, PropertyKey},
+    realm::{Realm, RealmInner},
     value::PreferredType,
     Context, JsResult, JsString, JsValue,
 };
-use boa_gc::{self, Finalize, Gc, GcBox, GcRefCell, Trace};
+use boa_gc::{self, Finalize, Gc, GcBox, GcRefCell, Trace, WeakGc};
 use boa_macros::js_str;
 use std::{
     cell::RefCell,
@@ -92,8 +94,20 @@ impl JsObject {
             inner: coerce_gc(gc),
         }
     }
+
+    /// Creates a new lazy `JsObject` from its inner object and its vtable.
+    /// This object will call init([realm]) when it's first accessed
+    pub(crate) fn lazy(init: fn(&Realm) -> (), realm_inner: &WeakGc<RealmInner>) -> Self {
+        let data = LazyBuiltIn {
+            init_and_realm: Some((init, realm_inner.clone())),
+            kind: BuiltinKind::Ordinary,
+        };
+
+        Self::from_proto_and_data(None, data)
+    }
+
     /// Creates a new lazy `JsObject` from its inner object and its vtable.
-    /// This is used for built-in objects that are lazily initialized.
+    /// This is used for built-in objects that are prototypes of Constructors.
     pub(crate) fn lazy_prototype(constructor: JsObject<LazyBuiltIn>) -> Self {
         Self::from_proto_and_data(None, LazyPrototype { constructor })
     }