qmlsc: Support Math static properties

The javascript Math object presents some static properties that allow
access to some general mathematical constants.

Currently, `qmlsc` will refuse to generate optimized code for those
properties when used in a binding, for example given:

```
import QtQuick

Window {
    width: 200 * Math.PI
}

```

`qmlsc` will report a warning and will not generate code for the "width"
binding.

To allow `qmlsc` to generate optimized code for such cases, the handling
of `Math` related properties lookups is now specialized.

`QQmlJSTypePropagator::propagatePropertyLookup`, which is called when
dealing with an access such as `Math.PI`, was modified to consider the
result type a "double" when dealing with properties on the `Math`
object.

`QQmlJSCodeGenerator::generate_GetLookupHelper`, which generates the
code that provides a value for the property access, was modified to
special case lookups on the `Math` object.

If a property is being looked up on the `Math` object, `qmlsc` will now
generate a direct assignment for the output variable to a constant value
that is suitable for the accessed property.

A test was added to ensure that the snippet from the bug-report now
compiles without warnings.

A test was added to ensure that the properties from the Math global
object have an approximately correct value.

Fixes: QTBUG-113150
Change-Id: I8903794fc8ce2b55532a4706e1bda07a7b73f311
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

4 files changed, 53 insertions, 0 deletions

diff --git a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
index 483a606040..4d9b6aea41 100644
--- a/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
+++ b/tests/auto/qml/qmlcppcodegen/data/CMakeLists.txt
@@ -195,6 +195,7 @@ set(qml_files
     math.qml
     mathMinMax.qml
     mathOperations.qml
+    mathStaticProperties.qml
     mergedObjectRead.qml
     mergedObjectWrite.qml
     methodOnListLookup.qml
@@ -227,6 +228,7 @@ set(qml_files
     popContextAfterRet.qml
     prefixedMetaType.qml
     pressAndHoldButton.qml
+    qtbug113150.qml
     reduceWithNullThis.qml
     readEnumFromInstance.qml
     readonlyListProperty.qml
diff --git a/tests/auto/qml/qmlcppcodegen/data/mathStaticProperties.qml b/tests/auto/qml/qmlcppcodegen/data/mathStaticProperties.qml
new file mode 100644
index 0000000000..fad74a28bd
--- /dev/null
+++ b/tests/auto/qml/qmlcppcodegen/data/mathStaticProperties.qml
@@ -0,0 +1,17 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+pragma Strict
+
+import QML
+
+QtObject {
+    property double e: Math.E
+    property double ln10: Math.LN10
+    property double ln2: Math.LN2
+    property double log10e: Math.LOG10E
+    property double log2e: Math.LOG2E
+    property double pi: Math.PI
+    property double sqrt1_2: Math.SQRT1_2
+    property double sqrt2: Math.SQRT2
+}
diff --git a/tests/auto/qml/qmlcppcodegen/data/qtbug113150.qml b/tests/auto/qml/qmlcppcodegen/data/qtbug113150.qml
new file mode 100644
index 0000000000..c7103eaf05
--- /dev/null
+++ b/tests/auto/qml/qmlcppcodegen/data/qtbug113150.qml
@@ -0,0 +1,13 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+pragma Strict
+
+import QtQuick
+
+Window {
+    // If static properties of the Math global object are not directly
+    // supported, a warning should be issued in turn failing the build
+    // due to `pragma Strict`.
+    width: 200 * Math.PI
+}
diff --git a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
index b8bb660516..ae8ef49b22 100644
--- a/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
+++ b/tests/auto/qml/qmlcppcodegen/tst_qmlcppcodegen.cpp
@@ -160,6 +160,7 @@ private slots:
     void math();
     void mathMinMax();
     void mathOperations();
+    void mathStaticProperties();
     void mergedObjectReadWrite();
     void methodOnListLookup();
     void methods();
@@ -3215,6 +3216,26 @@ void tst_QmlCppCodegen::mathOperations()
     }
 }
 
+void tst_QmlCppCodegen::mathStaticProperties()
+{
+    QQmlEngine engine;
+    QQmlComponent component(&engine, QUrl(u"qrc:/qt/qml/TestTypes/mathStaticProperties.qml"_s));
+    QVERIFY2(!component.isError(), component.errorString().toUtf8());
+    QScopedPointer<QObject> object(component.create());
+    QVERIFY(!object.isNull());
+
+    // Approximate values based on
+    // https://262.ecma-international.org/14.0/#sec-value-properties-of-the-math-object
+    QCOMPARE(object->property("e").toDouble(), 2.7182818284590452354);
+    QCOMPARE(object->property("ln10").toDouble(), 2.302585092994046);
+    QCOMPARE(object->property("ln2").toDouble(), 0.6931471805599453);
+    QCOMPARE(object->property("log10e").toDouble(), 0.4342944819032518);
+    QCOMPARE(object->property("log2e").toDouble(), 1.4426950408889634);
+    QCOMPARE(object->property("pi").toDouble(), 3.1415926535897932);
+    QCOMPARE(object->property("sqrt1_2").toDouble(), 0.7071067811865476);
+    QCOMPARE(object->property("sqrt2").toDouble(), 1.4142135623730951);
+}
+
 void tst_QmlCppCodegen::mergedObjectReadWrite()
 {
     QQmlEngine e;