Add JS_SetImmutableArrayBuffer (#1350)

Fixes: #1347

Author: bnoordhuis

api-test.c

@@ -858,6 +858,53 @@ static void slice_string_tocstring(void)
     JS_FreeRuntime(rt);
 }
 
+static void immutable_array_buffer(void)
+{
+    JSValue obj, ret;
+    bool immutable;
+    char buf[96];
+    int i, v;
+
+    JSRuntime *rt = JS_NewRuntime();
+    JSContext *ctx = JS_NewContext(rt);
+    for (i = 0; i < 2; i++) {
+        obj = JS_NewObject(ctx);
+        immutable = (i == 0);
+        assert(-1 == JS_IsImmutableArrayBuffer(JS_NULL));
+        assert(-1 == JS_IsImmutableArrayBuffer(JS_UNDEFINED));
+        assert(-1 == JS_IsImmutableArrayBuffer(obj));
+        assert(-1 == JS_SetImmutableArrayBuffer(JS_NULL, immutable));
+        assert(-1 == JS_SetImmutableArrayBuffer(JS_UNDEFINED, immutable));
+        assert(-1 == JS_SetImmutableArrayBuffer(obj, immutable));
+        JS_FreeValue(ctx, obj);
+    }
+    obj = eval(ctx, "globalThis.ab = new ArrayBuffer(1)");
+    assert(!JS_IsException(obj));
+    assert(JS_IsArrayBuffer(obj));
+    assert(!JS_IsImmutableArrayBuffer(obj));
+    for (i = 1; i <= 3; i++) {
+        immutable = (i == 2);
+        if (i > 1)
+            JS_SetImmutableArrayBuffer(obj, immutable);
+        assert(immutable == JS_IsImmutableArrayBuffer(obj));
+        snprintf(buf, sizeof(buf),
+                 "var ta = new Uint8Array(ab); ta[0] = %d; ta[0]", i);
+        ret = eval(ctx, buf);
+        assert(!JS_IsException(ret));
+        assert(JS_IsNumber(ret));
+        assert(0 == JS_ToInt32(ctx, &v, ret));
+        JS_FreeValue(ctx, ret);
+        if (immutable) {
+            assert(v != i);
+        } else {
+            assert(v == i);
+        }
+    }
+    JS_FreeValue(ctx, obj);
+    JS_FreeContext(ctx);
+    JS_FreeRuntime(rt);
+}
+
 int main(void)
 {
     cfunctions();
@@ -875,5 +922,6 @@ int main(void)
     new_errors();
     global_object_prototype();
     slice_string_tocstring();
+    immutable_array_buffer();
     return 0;
 }

quickjs.c

@@ -55763,6 +55763,23 @@ void JS_DetachArrayBuffer(JSContext *ctx, JSValueConst obj)
     }
 }
 
+int JS_IsImmutableArrayBuffer(JSValueConst obj)
+{
+    JSArrayBuffer *abuf = JS_GetOpaque(obj, JS_CLASS_ARRAY_BUFFER);
+    if (!abuf)
+        return -1;
+    return abuf->immutable;
+}
+
+int JS_SetImmutableArrayBuffer(JSValueConst obj, bool immutable)
+{
+    JSArrayBuffer *abuf = JS_GetOpaque(obj, JS_CLASS_ARRAY_BUFFER);
+    if (!abuf)
+        return -1;
+    abuf->immutable = immutable;
+    return 0;
+}
+
 /* get an ArrayBuffer or SharedArrayBuffer */
 static JSArrayBuffer *js_get_array_buffer(JSContext *ctx, JSValueConst obj)
 {

quickjs.h

@@ -1061,6 +1061,10 @@ JS_EXTERN JSValue JS_NewArrayBufferCopy(JSContext *ctx, const uint8_t *buf, size
 JS_EXTERN void JS_DetachArrayBuffer(JSContext *ctx, JSValueConst obj);
 JS_EXTERN uint8_t *JS_GetArrayBuffer(JSContext *ctx, size_t *psize, JSValueConst obj);
 JS_EXTERN bool JS_IsArrayBuffer(JSValueConst obj);
+// returns true or false if obj is an ArrayBuffer, -1 otherwise
+JS_EXTERN int JS_IsImmutableArrayBuffer(JSValueConst obj);
+// returns 0 if obj is an ArrayBuffer, -1 otherwise
+JS_EXTERN int JS_SetImmutableArrayBuffer(JSValueConst obj, bool immutable);
 JS_EXTERN uint8_t *JS_GetUint8Array(JSContext *ctx, size_t *psize, JSValueConst obj);
 
 typedef enum JSTypedArrayEnum {