Use consistent ordering in QShader

Fixes: QTBUG-101923
Change-Id: I62df3eba773350e47ed650acb00bc42b3ce6a899
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

src/gui/rhi/qshader.cpp

@@ -563,6 +563,22 @@ size_t qHash(const QShaderVersion &s, size_t seed) noexcept
 }
 #endif
 
+/*!
+    Establishes a sorting order between the two QShaderVersion \a lhs and \a rhs.
+
+    \relates QShaderVersion
+ */
+bool operator<(const QShaderVersion &lhs, const QShaderVersion &rhs) noexcept
+{
+    if (lhs.version() < rhs.version())
+        return true;
+
+    if (lhs.version() == rhs.version())
+        return int(lhs.flags()) < int(rhs.flags());
+
+    return false;
+}
+
 /*!
     \internal
     \fn bool operator!=(const QShaderVersion &lhs, const QShaderVersion &rhs)
@@ -584,6 +600,28 @@ bool operator==(const QShaderKey &lhs, const QShaderKey &rhs) noexcept
             && lhs.sourceVariant() == rhs.sourceVariant();
 }
 
+/*!
+    Establishes a sorting order between the two keys \a lhs and \a rhs.
+
+    \relates QShaderKey
+ */
+bool operator<(const QShaderKey &lhs, const QShaderKey &rhs) noexcept
+{
+    if (int(lhs.source()) < int(rhs.source()))
+        return true;
+
+    if (int(lhs.source()) == int(rhs.source())) {
+        if (lhs.sourceVersion() < rhs.sourceVersion())
+            return true;
+        if (lhs.sourceVersion() == rhs.sourceVersion()) {
+            if (int(lhs.sourceVariant()) < int(rhs.sourceVariant()))
+                return true;
+        }
+    }
+
+    return false;
+}
+
 /*!
     \internal
     \fn bool operator!=(const QShaderKey &lhs, const QShaderKey &rhs)

src/gui/rhi/qshader_p.h

@@ -187,7 +187,9 @@ inline bool operator!=(const QShader &lhs, const QShader &rhs) noexcept
 }
 
 Q_GUI_EXPORT bool operator==(const QShaderVersion &lhs, const QShaderVersion &rhs) noexcept;
+Q_GUI_EXPORT bool operator<(const QShaderVersion &lhs, const QShaderVersion &rhs) noexcept;
 Q_GUI_EXPORT bool operator==(const QShaderKey &lhs, const QShaderKey &rhs) noexcept;
+Q_GUI_EXPORT bool operator<(const QShaderKey &lhs, const QShaderKey &rhs) noexcept;
 Q_GUI_EXPORT bool operator==(const QShaderCode &lhs, const QShaderCode &rhs) noexcept;
 
 inline bool operator!=(const QShaderVersion &lhs, const QShaderVersion &rhs) noexcept

src/gui/rhi/qshader_p_p.h

@@ -17,7 +17,7 @@
 
 #include "qshader_p.h"
 #include <QtCore/QAtomicInt>
-#include <QtCore/QHash>
+#include <QtCore/QMap>
 #include <QtCore/QDebug>
 
 QT_BEGIN_NAMESPACE
@@ -54,9 +54,10 @@ struct Q_GUI_EXPORT QShaderPrivate
     int qsbVersion = QSB_VERSION;
     QShader::Stage stage = QShader::VertexStage;
     QShaderDescription desc;
-    QHash<QShaderKey, QShaderCode> shaders;
-    QHash<QShaderKey, QShader::NativeResourceBindingMap> bindings;
-    QHash<QShaderKey, QShader::SeparateToCombinedImageSamplerMappingList> combinedImageMap;
+    // QMap not QHash because we need to be able to iterate based on sorted keys
+    QMap<QShaderKey, QShaderCode> shaders;
+    QMap<QShaderKey, QShader::NativeResourceBindingMap> bindings;
+    QMap<QShaderKey, QShader::SeparateToCombinedImageSamplerMappingList> combinedImageMap;
 };
 
 QT_END_NAMESPACE

tests/auto/gui/rhi/qshader/tst_qshader.cpp

@@ -18,6 +18,7 @@ private slots:
     void genVariants();
     void shaderDescImplicitSharing();
     void bakedShaderImplicitSharing();
+    void sortedKeys();
     void mslResourceMapping();
     void serializeShaderDesc();
     void comparison();
@@ -238,6 +239,16 @@ void tst_QShader::bakedShaderImplicitSharing()
     }
 }
 
+void tst_QShader::sortedKeys()
+{
+    QShader s = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));
+    QVERIFY(s.isValid());
+    QList<QShaderKey> availableShaders = s.availableShaders();
+    QCOMPARE(availableShaders.count(), 7);
+    std::sort(availableShaders.begin(), availableShaders.end());
+    QCOMPARE(availableShaders, s.availableShaders());
+}
+
 void tst_QShader::mslResourceMapping()
 {
     QShader s = getShader(QLatin1String(":/data/texture_all_v4.frag.qsb"));