1 files changed, 63 insertions, 13 deletions

diff --git a/deps/v8/src/builtins/string.tq b/deps/v8/src/builtins/string.tq
index dbcc5799e1..7f007680e9 100644
--- a/deps/v8/src/builtins/string.tq
+++ b/deps/v8/src/builtins/string.tq
@@ -7,15 +7,15 @@
 namespace string {
   // ES6 #sec-string.prototype.tostring
   transitioning javascript builtin
-  StringPrototypeToString(js-implicit context: Context)(receiver: Object):
-      Object {
+  StringPrototypeToString(js-implicit context: Context, receiver: JSAny)():
+      JSAny {
     return ToThisValue(receiver, kString, 'String.prototype.toString');
   }
 
   // ES6 #sec-string.prototype.valueof
   transitioning javascript builtin
-  StringPrototypeValueOf(js-implicit context: Context)(receiver: Object):
-      Object {
+  StringPrototypeValueOf(js-implicit context: Context, receiver: JSAny)():
+      JSAny {
     return ToThisValue(receiver, kString, 'String.prototype.valueOf');
   }
 
@@ -29,7 +29,8 @@ namespace string {
     const kind = PACKED_ELEMENTS;
     const stringLength: intptr = string.length_intptr;
 
-    const map: Map = LoadJSArrayElementsMap(kind, LoadNativeContext(context));
+    const nativeContext = LoadNativeContext(context);
+    const map: Map = LoadJSArrayElementsMap(kind, nativeContext);
     const array: JSArray = AllocateJSArray(
         kind, map, stringLength, SmiTag(stringLength),
         kAllowLargeObjectAllocation);
@@ -53,7 +54,7 @@ namespace string {
   }
 
   transitioning macro GenerateStringAt(implicit context: Context)(
-      receiver: Object, position: Object,
+      receiver: JSAny, position: JSAny,
       methodName: constexpr string): never labels
   IfInBounds(String, intptr, intptr), IfOutOfBounds {
     // Check that {receiver} is coercible to Object and convert it to a String.
@@ -71,8 +72,7 @@ namespace string {
 
   // ES6 #sec-string.prototype.charat
   transitioning javascript builtin StringPrototypeCharAt(
-      js-implicit context: Context,
-      receiver: Object)(position: Object): Object {
+      js-implicit context: Context, receiver: JSAny)(position: JSAny): JSAny {
     try {
       GenerateStringAt(receiver, position, 'String.prototype.charAt')
           otherwise IfInBounds, IfOutOfBounds;
@@ -88,8 +88,7 @@ namespace string {
 
   // ES6 #sec-string.prototype.charcodeat
   transitioning javascript builtin StringPrototypeCharCodeAt(
-      js-implicit context: Context,
-      receiver: Object)(position: Object): Object {
+      js-implicit context: Context, receiver: JSAny)(position: JSAny): JSAny {
     try {
       GenerateStringAt(receiver, position, 'String.prototype.charCodeAt')
           otherwise IfInBounds, IfOutOfBounds;
@@ -105,8 +104,7 @@ namespace string {
 
   // ES6 #sec-string.prototype.codepointat
   transitioning javascript builtin StringPrototypeCodePointAt(
-      js-implicit context: Context,
-      receiver: Object)(position: Object): Object {
+      js-implicit context: Context, receiver: JSAny)(position: JSAny): JSAny {
     try {
       GenerateStringAt(receiver, position, 'String.prototype.codePointAt')
           otherwise IfInBounds, IfOutOfBounds;
@@ -125,7 +123,7 @@ namespace string {
   // ES6 String.prototype.concat(...args)
   // ES6 #sec-string.prototype.concat
   transitioning javascript builtin StringPrototypeConcat(
-      js-implicit context: Context, receiver: Object)(...arguments): Object {
+      js-implicit context: Context, receiver: JSAny)(...arguments): JSAny {
     // Check that {receiver} is coercible to Object and convert it to a String.
     let string: String = ToThisString(receiver, 'String.prototype.concat');
 
@@ -137,4 +135,56 @@ namespace string {
     }
     return string;
   }
+
+  extern transitioning runtime
+  SymbolDescriptiveString(implicit context: Context)(Symbol): String;
+
+  // ES #sec-string-constructor
+  // https://tc39.github.io/ecma262/#sec-string-constructor
+  transitioning javascript builtin StringConstructor(
+      js-implicit context: Context, receiver: JSAny, newTarget: JSAny,
+      target: JSFunction)(...arguments): JSAny {
+    const length: intptr = Convert<intptr>(arguments.length);
+    let s: String;
+    // 1. If no arguments were passed to this function invocation, let s be "".
+    if (length == 0) {
+      s = EmptyStringConstant();
+    } else {
+      // 2. Else,
+      // 2. a. If NewTarget is undefined and Type(value) is Symbol, return
+      // SymbolDescriptiveString(value).
+      if (newTarget == Undefined) {
+        typeswitch (arguments[0]) {
+          case (value: Symbol): {
+            return SymbolDescriptiveString(value);
+          }
+          case (JSAny): {
+          }
+        }
+      }
+      // 2. b. Let s be ? ToString(value).
+      s = ToString_Inline(context, arguments[0]);
+    }
+    // 3. If NewTarget is undefined, return s.
+    if (newTarget == Undefined) {
+      return s;
+    }
+    // 4. Return ! StringCreate(s, ? GetPrototypeFromConstructor(NewTarget,
+    // "%String.prototype%")).
+    const map = GetDerivedMap(target, UnsafeCast<JSReceiver>(newTarget));
+    const obj =
+        UnsafeCast<JSPrimitiveWrapper>(AllocateFastOrSlowJSObjectFromMap(map));
+    obj.value = s;
+    return obj;
+  }
+
+  transitioning builtin StringAddConvertLeft(implicit context: Context)(
+      left: JSAny, right: String): String {
+    return ToStringImpl(context, ToPrimitiveDefault(left)) + right;
+  }
+
+  transitioning builtin StringAddConvertRight(implicit context: Context)(
+      left: String, right: JSAny): String {
+    return left + ToStringImpl(context, ToPrimitiveDefault(right));
+  }
 }