Normative: prohibit using setFromBase64/setFromHex on immutable-backed Uint8Arrays (Apple Launch Event Presentation)

Author: Free Social Media Posts PSD

package.json

@@ -16,7 +16,7 @@
  },
  "license": "MIT",
  "devDependencies": {
- "@tc39/ecma262-biblio": "2.1.2862",
+ "@tc39/ecma262-biblio": "2.1.3025",
  "ecmarkup": "^21.2.0",
  "jsdom": "^25.0.1",
  "parse5-html-rewriting-stream": "^7.0.0",

spec.emu

@@ -590,6 +590,91 @@ markEffects: true
  </emu-clause>
  </emu-clause>
  </emu-clause>
+
+ <emu-clause id="sec-uint8array">
+ <h1>Uint8Array Objects</h1>
+
+ <emu-clause id="sec-additional-properties-of-the-uint8array-prototype-object" number="2">
+ <h1>Additional Properties of the Uint8Array Prototype Object</h1>
+
+ <emu-clause id="sec-uint8array.prototype.setfrombase64">
+ <h1>Uint8Array.prototype.setFromBase64 ( _string_ [ , _options_ ] )</h1>
+ <emu-alg>
+ 1. Let _into_ be the *this* value.
+ 1. Perform ? ValidateUint8Array(_into_<ins>, ~write~</ins>).
+ 1. If _string_ is not a String, throw a *TypeError* exception.
+ 1. Let _opts_ be ? GetOptionsObject(_options_).
+ 1. Let _alphabet_ be ? Get(_opts_, *"alphabet"*).
+ 1. If _alphabet_ is *undefined*, set _alphabet_ to *"base64"*.
+ 1. If _alphabet_ is neither *"base64"* nor *"base64url"*, throw a *TypeError* exception.
+ 1. Let _lastChunkHandling_ be ? Get(_opts_, *"lastChunkHandling"*).
+ 1. If _lastChunkHandling_ is *undefined*, set _lastChunkHandling_ to *"loose"*.
+ 1. If _lastChunkHandling_ is not one of *"loose"*, *"strict"*, or *"stop-before-partial"*, throw a *TypeError* exception.
+ 1. Let _taRecord_ be MakeTypedArrayWithBufferWitnessRecord(_into_, ~seq-cst~).
+ 1. If IsTypedArrayOutOfBounds(_taRecord_) is *true*, throw a *TypeError* exception.
+ 1. Let _byteLength_ be TypedArrayLength(_taRecord_).
+ 1. Let _result_ be FromBase64(_string_, _alphabet_, _lastChunkHandling_, _byteLength_).
+ 1. Let _bytes_ be _result_.[[Bytes]].
+ 1. Let _written_ be the number of elements in _bytes_.
+ 1. NOTE: FromBase64 does not invoke any user code, so the ArrayBuffer backing _into_ cannot have been detached or shrunk.
+ 1. Assert: _written_ ≤ _byteLength_.
+ 1. Perform SetUint8ArrayBytes(_into_, _bytes_).
+ 1. If _result_.[[Error]] is not ~none~, then
+ 1. Return ThrowCompletion(_result_.[[Error]]).
+ 1. Let _resultObject_ be OrdinaryObjectCreate(%Object.prototype%).
+ 1. Perform ! CreateDataPropertyOrThrow(_resultObject_, *"read"*, 𝔽(_result_.[[Read]])).
+ 1. Perform ! CreateDataPropertyOrThrow(_resultObject_, *"written"*, 𝔽(_written_)).
+ 1. Return _resultObject_.
+ </emu-alg>
+ </emu-clause>
+
+ <emu-clause id="sec-uint8array.prototype.setfromhex">
+ <h1>Uint8Array.prototype.setFromHex ( _string_ )</h1>
+ <emu-alg>
+ 1. Let _into_ be the *this* value.
+ 1. Perform ? ValidateUint8Array(_into_<ins>, ~write~</ins>).
+ 1. If _string_ is not a String, throw a *TypeError* exception.
+ 1. Let _taRecord_ be MakeTypedArrayWithBufferWitnessRecord(_into_, ~seq-cst~).
+ 1. If IsTypedArrayOutOfBounds(_taRecord_) is *true*, throw a *TypeError* exception.
+ 1. Let _byteLength_ be TypedArrayLength(_taRecord_).
+ 1. Let _result_ be FromHex(_string_, _byteLength_).
+ 1. Let _bytes_ be _result_.[[Bytes]].
+ 1. Let _written_ be the number of elements in _bytes_.
+ 1. NOTE: FromHex does not invoke any user code, so the ArrayBuffer backing _into_ cannot have been detached or shrunk.
+ 1. Assert: _written_ ≤ _byteLength_.
+ 1. Perform SetUint8ArrayBytes(_into_, _bytes_).
+ 1. If _result_.[[Error]] is not ~none~, then
+ 1. Return ThrowCompletion(_result_.[[Error]]).
+ 1. Let _resultObject_ be OrdinaryObjectCreate(%Object.prototype%).
+ 1. Perform ! CreateDataPropertyOrThrow(_resultObject_, *"read"*, 𝔽(_result_.[[Read]])).
+ 1. Perform ! CreateDataPropertyOrThrow(_resultObject_, *"written"*, 𝔽(_written_)).
+ 1. Return _resultObject_.
+ </emu-alg>
+ </emu-clause>
+ </emu-clause>
+
+ <emu-clause id="sec-abstract-operations-for-uint8array-objects">
+ <h1>Abstract Operations for Uint8Array Objects</h1>
+
+ <emu-clause id="sec-validateuint8array" type="abstract operation">
+ <h1>
+ ValidateUint8Array (
+ _ta_: an ECMAScript language value,
+ <ins>optional _accessMode_: ~read~ or ~write~,</ins>
+ ): either a normal completion containing ~unused~ or a throw completion
+ </h1>
+ <dl class="header"></dl>
+ <emu-alg>
+ 1. <ins>If _accessMode_ is not present, set _accessMode_ to ~read~.</ins>
+ 1. Perform ? RequireInternalSlot(_ta_, [[TypedArrayName]]).
+ 1. If _ta_.[[TypedArrayName]] is not *"Uint8Array"*, throw a *TypeError* exception.
+ 1. <ins>Assert: _ta_ has a [[ViewedArrayBuffer]] internal slot.</ins>
+ 1. <ins>If _accessMode_ is ~write~ and IsImmutableBuffer(_ta_.[[ViewedArrayBuffer]]) is *true*, throw a *TypeError* exception.</ins>
+ 1. Return ~unused~.
+ </emu-alg>
+ </emu-clause>
+ </emu-clause>
+ </emu-clause>
 </emu-clause>
 
 <emu-clause id="sec-structured-data" number="25">