Feature gate nan boxing and implement fallback

boa_engine/Cargo.toml

@@ -14,6 +14,7 @@ readme = "../README.md"
 [features]
 profiler = ["boa_profiler/profiler"]
 deser = ["boa_interner/serde"]
+nan_boxing = []
 
 # Enable Boa's WHATWG console object implementation.
 console = []
@@ -43,6 +44,8 @@ once_cell = "1.10.0"
 tap = "1.0.1"
 icu = "0.5.0"
 sptr = "0.3.1"
+cfg-if = "1.0.0"
+num_enum = "0.5.7"
 
 [dev-dependencies]
 criterion = "0.3.5"

boa_engine/src/builtins/dataview/mod.rs

@@ -100,9 +100,9 @@ impl DataView {
     ) -> JsResult<JsValue> {
         let byte_length = args.get_or_undefined(2);
 
-        let buffer_obj = args
-            .get_or_undefined(0);
-        let buffer_obj = buffer_obj.as_object()
+        let buffer_obj = args.get_or_undefined(0);
+        let buffer_obj = buffer_obj
+            .as_object()
             .ok_or_else(|| context.construct_type_error("buffer must be an ArrayBuffer"))?;
 
         // 1. If NewTarget is undefined, throw a TypeError exception.

boa_engine/src/builtins/proxy/mod.rs

@@ -82,7 +82,11 @@ impl Proxy {
         }
 
         // 2. Return ? ProxyCreate(target, handler).
-        Self::create(&args.get_or_undefined(0), &args.get_or_undefined(1), context)
+        Self::create(
+            &args.get_or_undefined(0),
+            &args.get_or_undefined(1),
+            context,
+        )
     }
 
     // `10.5.14 ProxyCreate ( target, handler )`
@@ -131,7 +135,11 @@ impl Proxy {
     /// [spec]: https://tc39.es/ecma262/#sec-proxy.revocable
     fn revocable(_: &JsValue, args: &[JsValue], context: &mut Context) -> JsResult<JsValue> {
         // 1. Let p be ? ProxyCreate(target, handler).
-        let p = Self::create(&args.get_or_undefined(0),& args.get_or_undefined(1), context)?;
+        let p = Self::create(
+            &args.get_or_undefined(0),
+            &args.get_or_undefined(1),
+            context,
+        )?;
 
         // 3. Let revoker be ! CreateBuiltinFunction(revokerClosure, 0, "", « [[RevocableProxy]] »).
         // 4. Set revoker.[[RevocableProxy]] to p.

boa_engine/src/builtins/string/mod.rs

@@ -1521,7 +1521,7 @@ impl String {
         let fill_string = args.get_or_undefined(1);
 
         // 2. Return ? StringPad(O, maxLength, fillString, start).
-        Self::string_pad(this, &max_length,& fill_string, Placement::Start, context)
+        Self::string_pad(this, &max_length, &fill_string, Placement::Start, context)
     }
 
     /// String.prototype.trim()

boa_engine/src/value/conversions.rs

@@ -1,4 +1,6 @@
-use crate::JsString;
+use boa_profiler::Profiler;
+
+use crate::{object::JsObject, JsBigInt, JsString, JsSymbol};
 
 use super::{Display, JsValue};
 
@@ -9,63 +11,116 @@ impl From<&Self> for JsValue {
     }
 }
 
+impl<T> From<T> for JsValue
+where
+    T: Into<JsString>,
+{
+    #[inline]
+    fn from(value: T) -> Self {
+        let _timer = Profiler::global().start_event("From<String>", "value");
+
+        Self::string(value.into())
+    }
+}
+
+impl From<char> for JsValue {
+    #[inline]
+    fn from(value: char) -> Self {
+        Self::new(value.to_string())
+    }
+}
+
+impl From<JsSymbol> for JsValue {
+    #[inline]
+    fn from(value: JsSymbol) -> Self {
+        Self::symbol(value)
+    }
+}
+
+impl From<f32> for JsValue {
+    #[allow(clippy::float_cmp)]
+    #[inline]
+    fn from(value: f32) -> Self {
+        // if value as i32 as f64 == value {
+        //     Self::Integer(value as i32)
+        // } else {
+        Self::rational(value.into())
+        // }
+    }
+}
+
+impl From<f64> for JsValue {
+    #[allow(clippy::float_cmp)]
+    #[inline]
+    fn from(value: f64) -> Self {
+        // if value as i32 as f64 == value {
+        //     Self::Integer(value as i32)
+        // } else {
+        Self::rational(value)
+        // }
+    }
+}
+
 impl From<u8> for JsValue {
     #[inline]
     fn from(value: u8) -> Self {
-        Self::from(value as i32)
+        Self::integer(value.into())
     }
 }
 
 impl From<i8> for JsValue {
     #[inline]
     fn from(value: i8) -> Self {
-        Self::from(value as i32)
+        Self::integer(value.into())
     }
 }
 
 impl From<u16> for JsValue {
     #[inline]
     fn from(value: u16) -> Self {
-        Self::from(value as i32)
+        Self::integer(value.into())
     }
 }
 
 impl From<i16> for JsValue {
     #[inline]
     fn from(value: i16) -> Self {
-        Self::from(value as i32)
+        Self::integer(value.into())
     }
 }
 
 impl From<u32> for JsValue {
     #[inline]
     fn from(value: u32) -> Self {
         if let Ok(integer) = i32::try_from(value) {
-            Self::from(integer)
+            Self::integer(integer)
         } else {
-            Self::from(value as f64)
+            Self::rational(value.into())
         }
     }
 }
 
-impl From<usize> for JsValue {
+impl From<i32> for JsValue {
     #[inline]
-    fn from(value: usize) -> Self {
-        if let Ok(value) = i32::try_from(value) {
-            Self::from(value)
-        } else {
-            Self::from(value as f64)
-        }
+    fn from(value: i32) -> Self {
+        Self::integer(value)
+    }
+}
+
+impl From<JsBigInt> for JsValue {
+    #[inline]
+    fn from(value: JsBigInt) -> Self {
+        Self::bigint(value)
     }
 }
 
-impl From<isize> for JsValue {
+impl From<usize> for JsValue {
     #[inline]
-    fn from(value: isize) -> Self {
+    fn from(value: usize) -> Self {
         if let Ok(value) = i32::try_from(value) {
-            Self::from(value)
+            Self::integer(value)
         } else {
-            Self::from(value as f64)
+            Self::rational(value as f64)
         }
     }
 }
@@ -74,9 +129,9 @@ impl From<u64> for JsValue {
     #[inline]
     fn from(value: u64) -> Self {
         if let Ok(value) = i32::try_from(value) {
-            Self::from(value)
+            Self::integer(value)
         } else {
-            Self::from(value as f64)
+            Self::rational(value as f64)
         }
     }
 }
@@ -85,57 +140,32 @@ impl From<i64> for JsValue {
     #[inline]
     fn from(value: i64) -> Self {
         if let Ok(value) = i32::try_from(value) {
-            Self::from(value)
+            Self::integer(value)
         } else {
-            Self::from(value as f64)
+            Self::rational(value as f64)
         }
     }
 }
 
-impl From<f32> for JsValue {
-    #[allow(clippy::float_cmp)]
-    #[inline]
-    fn from(value: f32) -> Self {
-        // if value as i32 as f64 == value {
-        //     Self::Integer(value as i32)
-        // } else {
-        Self::from(value as f64)
-        // }
-    }
-}
-
-impl From<char> for JsValue {
-    #[inline]
-    fn from(value: char) -> Self {
-        Self::from(value.to_string())
-    }
-}
-
-impl From<&str> for JsValue {
-    #[inline]
-    fn from(string: &str) -> Self {
-        Self::from(JsString::new(string))
-    }
-}
-
-impl From<Box<str>> for JsValue {
+impl From<bool> for JsValue {
     #[inline]
-    fn from(string: Box<str>) -> Self {
-        Self::from(JsString::new(string))
+    fn from(value: bool) -> Self {
+        Self::boolean(value)
     }
 }
 
-impl From<&String> for JsValue {
+impl From<JsObject> for JsValue {
     #[inline]
-    fn from(string: &String) -> Self {
-        Self::from(JsString::new(string.as_str()))
+    fn from(object: JsObject) -> Self {
+        let _timer = Profiler::global().start_event("From<JsObject>", "value");
+        Self::object(object)
     }
 }
 
-impl From<String> for JsValue {
+impl From<()> for JsValue {
     #[inline]
-    fn from(string: String) -> Self {
-        Self::from(JsString::new(string))
+    fn from(_: ()) -> Self {
+        Self::null()
     }
 }
 

boa_engine/src/value/equality.rs

@@ -70,7 +70,7 @@ impl JsValue {
             //    b. If n is NaN, return false.
             //    c. Return the result of the comparison x == n.
             (JsVariant::BigInt(a), JsVariant::String(ref b)) => match JsBigInt::from_string(b) {
-                Some(b) => a == b,
+                Some(b) => *a == b,
                 None => false,
             },