From a1ea2b8ec057bca58fdb5e9498e2f302ef0e61b4 Mon Sep 17 00:00:00 2001
From: Robin Burchell <robin.burchell@crimson.no>
Date: Thu, 24 May 2018 21:19:22 +0200
Subject: qv4arrayobject: Implement Array.prototype.fill according to ES7

Task-number: QTBUG-56824
Change-Id: Ib12b9fe5ebdd5375f17cf4927eb9b4e292731932
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
---
 src/qml/jsruntime/qv4arrayobject.cpp | 37 ++++++++++++++++++++++++++++++++++++
 src/qml/jsruntime/qv4arrayobject_p.h |  1 +
 src/qml/jsruntime/qv4object_p.h      | 17 +++++++++++++++++
 3 files changed, 55 insertions(+)

(limited to 'src/qml')

diff --git a/src/qml/jsruntime/qv4arrayobject.cpp b/src/qml/jsruntime/qv4arrayobject.cpp
index c04edbe872..f8398d206d 100644
--- a/src/qml/jsruntime/qv4arrayobject.cpp
+++ b/src/qml/jsruntime/qv4arrayobject.cpp
@@ -116,6 +116,7 @@ void ArrayPrototype::init(ExecutionEngine *engine, Object *ctor)
     defineDefaultProperty(QStringLiteral("keys"), method_keys, 0);
     defineDefaultProperty(QStringLiteral("lastIndexOf"), method_lastIndexOf, 1);
     defineDefaultProperty(QStringLiteral("every"), method_every, 1);
+    defineDefaultProperty(QStringLiteral("fill"), method_fill, 1);
     defineDefaultProperty(QStringLiteral("some"), method_some, 1);
     defineDefaultProperty(QStringLiteral("forEach"), method_forEach, 1);
     defineDefaultProperty(QStringLiteral("map"), method_map, 1);
@@ -854,6 +855,42 @@ ReturnedValue ArrayPrototype::method_every(const FunctionObject *b, const Value
     return Encode(ok);
 }
 
+ReturnedValue ArrayPrototype::method_fill(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
+{
+    Scope scope(b);
+    ScopedObject instance(scope, thisObject->toObject(scope.engine));
+    if (!instance)
+        RETURN_UNDEFINED();
+
+    uint len = instance->getLength();
+    int relativeStart = argc > 1 ? argv[1].toInteger() : 0;
+    int relativeEnd = len;
+    if (argc > 2 && !argv[2].isUndefined()) {
+        relativeEnd = argv[2].toInteger();
+    }
+    uint k = 0;
+    uint fin = 0;
+
+    if (relativeStart < 0) {
+        k = std::max(len+relativeStart, uint(0));
+    } else {
+        k = std::min(uint(relativeStart), len);
+    }
+
+    if (relativeEnd < 0) {
+        fin = std::max(len + relativeEnd, uint(0));
+    } else {
+        fin = std::min(uint(relativeEnd), len);
+    }
+
+    while (k < fin) {
+        instance->setIndexed(k, argv[0], QV4::Object::DoThrowOnRejection);
+        k++;
+    }
+
+    return instance.asReturnedValue();
+}
+
 ReturnedValue ArrayPrototype::method_some(const FunctionObject *b, const Value *thisObject, const Value *argv, int argc)
 {
     Scope scope(b);
diff --git a/src/qml/jsruntime/qv4arrayobject_p.h b/src/qml/jsruntime/qv4arrayobject_p.h
index 31067b0c39..a8feb65e80 100644
--- a/src/qml/jsruntime/qv4arrayobject_p.h
+++ b/src/qml/jsruntime/qv4arrayobject_p.h
@@ -98,6 +98,7 @@ struct ArrayPrototype: ArrayObject
     static ReturnedValue method_keys(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_lastIndexOf(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_every(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
+    static ReturnedValue method_fill(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_some(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_forEach(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
     static ReturnedValue method_map(const FunctionObject *, const Value *thisObject, const Value *argv, int argc);
diff --git a/src/qml/jsruntime/qv4object_p.h b/src/qml/jsruntime/qv4object_p.h
index 7cc99376be..5ad67635db 100644
--- a/src/qml/jsruntime/qv4object_p.h
+++ b/src/qml/jsruntime/qv4object_p.h
@@ -385,6 +385,23 @@ public:
         DoNotThrow
     };
 
+    // This is the same as set(), but it doesn't require creating a string key,
+    // which is much more efficient for the array case.
+    inline bool setIndexed(uint idx, const Value &v, ThrowOnFailure shouldThrow)
+    {
+        bool ret = vtable()->putIndexed(this, idx, v);
+        // ES6: 7.3.3, 6: If success is false and Throw is true, throw a TypeError exception.
+        if (!ret && shouldThrow == ThrowOnFailure::DoThrowOnRejection) {
+            ExecutionEngine *e = engine();
+            if (!e->hasException) { // allow a custom set impl to throw itself
+                QString message = QLatin1String("Cannot assign to read-only property \"") +
+                        QString::number(idx) + QLatin1Char('\"');
+                e->throwTypeError(message);
+            }
+        }
+        return ret;
+    }
+
     // ES6: 7.3.3 Set (O, P, V, Throw)
     inline bool set(StringOrSymbol *name, const Value &v, ThrowOnFailure shouldThrow)
     {
-- 
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