Add namespaces to qdbusxml2cpp

[ChangeLog][QtDBus][qdbusxml2cpp] The Qt D-Bus XML compiler
(qdbusxml2cpp) now supports the command-line argument -namespace
<namespace>, which encapsulates all generated classes within the
specified namespace to prevent class name conflicts.

Fixes: QTBUG-133611
Change-Id: Ic3473dfc33dcf22f5be727236fe546b70b2b015b
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

src/tools/qdbusxml2cpp/qdbusxml2cpp.cpp

@@ -80,6 +80,7 @@ private:
 
     QString globalClassName;
     QString parentClassName;
+    QString customNamespace;
     QString inputFile;
     bool skipNamespaces = false;
     bool includeMocs = false;
@@ -608,6 +609,13 @@ void QDBusXmlToCpp::writeProxy(const QString &filename,
             cs << "#include \"" << headerName << "\"\n\n";
     }
 
+    if (!customNamespace.isEmpty()) {
+        hs << "namespace " << customNamespace << " { \n"
+              "\n";
+        cs << "namespace " << customNamespace << " { \n"
+              "\n";
+    }
+
     for (const QDBusIntrospection::Interface *interface : interfaces) {
         QString className = classNameForInterface(interface->name, Proxy);
 
@@ -799,6 +807,13 @@ void QDBusXmlToCpp::writeProxy(const QString &filename,
         hs << "};\n\n";
     }
 
+    if (!customNamespace.isEmpty()) {
+        hs << "} // end of namespace " << customNamespace << "\n"
+           << "\n";
+        cs << "} // end of namespace " << customNamespace << "\n"
+           << "\n";
+    }
+
     if (!skipNamespaces) {
         QStringList last;
         QDBusIntrospection::Interfaces::ConstIterator it = interfaces.constBegin();
@@ -827,7 +842,8 @@ void QDBusXmlToCpp::writeProxy(const QString &filename,
             // add this class:
             if (!name.isEmpty()) {
                 hs << QString(current.size() * 2, u' ')
-                   << "using " << name << " = ::" << classNameForInterface(it->constData()->name, Proxy)
+                   << "using " << name << " = " << (customNamespace.isEmpty() ? "" : "::")
+                   << customNamespace << "::" << classNameForInterface(it->constData()->name, Proxy)
                    << ";\n";
             }
 
@@ -836,6 +852,8 @@ void QDBusXmlToCpp::writeProxy(const QString &filename,
             ++it;
             last = current;
         } while (true);
+
+        hs << "\n";
     }
 
     // close the include guard
@@ -937,6 +955,13 @@ void QDBusXmlToCpp::writeAdaptor(const QString &filename,
     if (parentClassName.isEmpty())
         parent = u"QObject"_s;
 
+    if (!customNamespace.isEmpty()) {
+        hs << "namespace " << customNamespace << " { \n"
+              "\n";
+        cs << "namespace " << customNamespace << " { \n"
+              "\n";
+    }
+
     for (const QDBusIntrospection::Interface *interface : interfaces) {
         QString className = classNameForInterface(interface->name, Adaptor);
 
@@ -1134,6 +1159,13 @@ void QDBusXmlToCpp::writeAdaptor(const QString &filename,
         hs << "};\n\n";
     }
 
+    if (!customNamespace.isEmpty()) {
+        hs << "} // end of namespace " << customNamespace << "\n"
+           << "\n";
+        cs << "} // end of namespace " << customNamespace << "\n"
+           << "\n";
+    }
+
     // close the include guard
     hs << "#endif\n";
 
@@ -1188,6 +1220,10 @@ int QDBusXmlToCpp::run(const QCoreApplication &app)
                 u"classname"_s);
     parser.addOption(classNameOption);
 
+    QCommandLineOption namespaceOption(QStringList{u"namespace"_s},
+                u"Put all generated classes into the namespace <namespace>. "_s, u"namespace"_s);
+    parser.addOption(namespaceOption);
+
     QCommandLineOption addIncludeOption(QStringList{u"i"_s, u"include"_s},
                 u"Add #include \"filename\" to the output"_s, u"filename"_s);
     parser.addOption(addIncludeOption);
@@ -1205,7 +1241,7 @@ int QDBusXmlToCpp::run(const QCoreApplication &app)
     parser.addOption(mocIncludeOption);
 
     QCommandLineOption noNamespaceOption(QStringList{u"N"_s, u"no-namespaces"_s},
-                u"Don't use namespaces"_s);
+                u"Do not export the generated class into the D-Bus specific namespace"_s);
     parser.addOption(noNamespaceOption);
 
     QCommandLineOption proxyCodeOption(QStringList{u"p"_s, u"proxy"_s},
@@ -1223,6 +1259,7 @@ int QDBusXmlToCpp::run(const QCoreApplication &app)
     includes = parser.values(addIncludeOption);
     globalIncludes = parser.values(addGlobalIncludeOption);
     parentClassName = parser.value(adapterParentOption);
+    customNamespace = parser.value(namespaceOption);
     includeMocs = parser.isSet(mocIncludeOption);
     skipNamespaces = parser.isSet(noNamespaceOption);
     QString proxyFile = parser.value(proxyCodeOption);

tests/auto/tools/qdbusxml2cpp/tst_qdbusxml2cpp.cpp

@@ -25,6 +25,8 @@ private slots:
     void missingAnnotation();
     void includeMoc_data();
     void includeMoc();
+    void customNamespace_data();
+    void customNamespace();
 };
 
 struct BasicTypeList {
@@ -482,6 +484,51 @@ void tst_qdbusxml2cpp::includeMoc()
     }
 }
 
+void tst_qdbusxml2cpp::customNamespace_data()
+{
+    QTest::addColumn<QByteArray>("namesp");
+
+    QTest::newRow("simple") << QByteArray("lancetest");
+    QTest::newRow("double") << QByteArray("lance::test");
+}
+
+void tst_qdbusxml2cpp::customNamespace()
+{
+    QFETCH(QByteArray, namesp);
+
+    QProcess process;
+    QStringList flags = {"-", "--namespace", namesp};
+
+    runTool(process,QByteArray{},flags);
+    QCOMPARE(process.exitCode(), 0);
+
+    QByteArray errOutput = process.readAllStandardError();
+    QVERIFY2(errOutput.isEmpty(), errOutput);
+
+    QByteArray fullOutput = process.readAll();
+    QVERIFY(!fullOutput.isEmpty());
+
+    // twice: once in the header, once in the implementation
+    static constexpr qsizetype requiredNameSpaceCount = 2;
+    QCOMPARE(fullOutput.count("namespace " + namesp + " {"), requiredNameSpaceCount);
+
+    static constexpr QByteArrayView endMarker("} // end of namespace ");
+    qsizetype startFrom = 0;
+    for (qsizetype i = 0; i < requiredNameSpaceCount; ++i) {
+        // make sure the namespace is there
+        qsizetype namespaceStart = fullOutput.indexOf("namespace " + namesp + " {", startFrom);
+        qsizetype namespaceEnd = fullOutput.indexOf(endMarker + namesp, namespaceStart);
+        QCOMPARE_GE(namespaceStart, 0);
+        QCOMPARE_GT(namespaceEnd, namespaceStart);
+        startFrom = namespaceEnd + endMarker.size() + namesp.size();
+
+        // make sure we cover a useful part of the source code with the namespace:
+        auto partOutput = QByteArrayView(fullOutput)
+                .slice(namespaceStart, startFrom - namespaceStart);
+        QCOMPARE(partOutput.count("{"), partOutput.count("}"));
+    }
+}
+
 QTEST_MAIN(tst_qdbusxml2cpp)
 
 #include "tst_qdbusxml2cpp.moc"