qmltc: support user-specified namespaces in the generated code

Already during the prototyping phase, conflicts in class names were
encountered within Qt code base. Those could be avoided by namespaces.
Initial qmltc logic was using meaningless "q_qmltc" namespace, so let's
improve that by allowing user-specified namespaces + making Qt's own
QML files (compiled to C++) being available under QT_NAMESPACE. The
latter is achieved by providing (and using) the internal version of a
qmltc-invoking function

Task-number: QTBUG-84368
Task-number: QTBUG-96040
Change-Id: I99cdf1baba8838c093b6b469f6744869f72af093
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

6 files changed, 30 insertions, 12 deletions

diff --git a/tools/qmltc/main.cpp b/tools/qmltc/main.cpp
index 801200839c..f6feb9ce2d 100644
--- a/tools/qmltc/main.cpp
+++ b/tools/qmltc/main.cpp
@@ -91,6 +91,11 @@ int main(int argc, char **argv)
         QCoreApplication::translate("main", "resource path")
     };
     parser.addOption(resourcePathOption);
+    QCommandLineOption namespaceOption {
+        u"namespace"_qs, QCoreApplication::translate("main", "Namespace of the generated C++ code"),
+        QCoreApplication::translate("main", "namespace")
+    };
+    parser.addOption(namespaceOption);
 
     parser.process(app);
 
@@ -160,6 +165,7 @@ int main(int argc, char **argv)
     QmltcCompilerInfo info;
     info.outputCppFile = outputCppFile;
     info.outputHFile = outputHFile;
+    info.outputNamespace = parser.value(namespaceOption);
     info.resourcePath = parser.value(resourcePathOption);
 
     QQmlJSImporter importer { importPaths, /* resource file mapper */ nullptr };
diff --git a/tools/qmltc/qmltccodewriter.cpp b/tools/qmltc/qmltccodewriter.cpp
index 9670f64667..7ce489c899 100644
--- a/tools/qmltc/qmltccodewriter.cpp
+++ b/tools/qmltc/qmltccodewriter.cpp
@@ -96,6 +96,7 @@ static std::pair<QString, QString> functionSignatures(const QmltcMethodBase &met
 
 void QmltcCodeWriter::writeGlobalHeader(QmltcOutputWrapper &code, const QString &sourcePath,
                                         const QString &hPath, const QString &cppPath,
+                                        const QString &outNamespace,
                                         const QSet<QString> &requiredCppIncludes)
 {
     Q_UNUSED(cppPath);
@@ -137,21 +138,26 @@ void QmltcCodeWriter::writeGlobalHeader(QmltcOutputWrapper &code, const QString
     code.rawAppendToCpp(u"#include <private/qobject_p.h>"); // NB: for private properties
     code.rawAppendToCpp(u"#include <private/qqmlglobal_p.h>"); // QQml_setParent_noEvent()
 
-    code.rawAppendToHeader(u""); // blank line
-    code.rawAppendToHeader(u"namespace q_qmltc {");
-
     code.rawAppendToCpp(u""); // blank line
     code.rawAppendToCpp(u"QT_USE_NAMESPACE // avoid issues with QT_NAMESPACE");
-    code.rawAppendToCpp(u"namespace q_qmltc {");
+    if (!outNamespace.isEmpty()) {
+        code.rawAppendToHeader(u""); // blank line
+        code.rawAppendToHeader(u"namespace %1 {"_qs.arg(outNamespace));
+        code.rawAppendToCpp(u""); // blank line
+        code.rawAppendToCpp(u"namespace %1 {"_qs.arg(outNamespace));
+    }
 }
 
-void QmltcCodeWriter::writeGlobalFooter(QmltcOutputWrapper &code, const QString &sourcePath)
+void QmltcCodeWriter::writeGlobalFooter(QmltcOutputWrapper &code, const QString &sourcePath,
+                                        const QString &outNamespace)
 {
-    code.rawAppendToCpp(u"} // namespace q_qmltc");
-    code.rawAppendToCpp(u""); // blank line
+    if (!outNamespace.isEmpty()) {
+        code.rawAppendToCpp(u"} // namespace %1"_qs.arg(outNamespace));
+        code.rawAppendToCpp(u""); // blank line
+        code.rawAppendToHeader(u"} // namespace %1"_qs.arg(outNamespace));
+        code.rawAppendToHeader(u""); // blank line
+    }
 
-    code.rawAppendToHeader(u"} // namespace q_qmltc");
-    code.rawAppendToHeader(u""); // blank line
     code.rawAppendToHeader(u"#endif // %1_H"_qs.arg(urlToMacro(sourcePath)));
     code.rawAppendToHeader(u""); // blank line
 }
@@ -179,7 +185,8 @@ static void writeToFile(const QString &path, const QByteArray &data)
 
 void QmltcCodeWriter::write(QmltcOutputWrapper &code, const QmltcProgram &program)
 {
-    writeGlobalHeader(code, program.url, program.hPath, program.cppPath, program.includes);
+    writeGlobalHeader(code, program.url, program.hPath, program.cppPath, program.outNamespace,
+                      program.includes);
     // TODO: keep the "NOT IMPLEMENTED" as long as we don't actually compile
     // useful code
     code.rawAppendToHeader(u"/* QMLTC: NOT IMPLEMENTED */");
@@ -191,7 +198,7 @@ void QmltcCodeWriter::write(QmltcOutputWrapper &code, const QmltcProgram &progra
     // write all the types and their content
     for (const QmltcType &type : qAsConst(program.compiledTypes))
         write(code, type);
-    writeGlobalFooter(code, program.url);
+    writeGlobalFooter(code, program.url, program.outNamespace);
 
     writeToFile(program.hPath, code.code().header.toUtf8());
     writeToFile(program.cppPath, code.code().cpp.toUtf8());
diff --git a/tools/qmltc/qmltccodewriter.h b/tools/qmltc/qmltccodewriter.h
index b34f198c88..a6f38da0a9 100644
--- a/tools/qmltc/qmltccodewriter.h
+++ b/tools/qmltc/qmltccodewriter.h
@@ -40,8 +40,10 @@ struct QmltcCodeWriter
 {
     static void writeGlobalHeader(QmltcOutputWrapper &code, const QString &sourcePath,
                                   const QString &hPath, const QString &cppPath,
+                                  const QString &outNamespace,
                                   const QSet<QString> &requiredCppIncludes);
-    static void writeGlobalFooter(QmltcOutputWrapper &code, const QString &sourcePath);
+    static void writeGlobalFooter(QmltcOutputWrapper &code, const QString &sourcePath,
+                                  const QString &outNamespace);
     static void write(QmltcOutputWrapper &code, const QmltcProgram &program);
     static void write(QmltcOutputWrapper &code, const QmltcType &type);
     static void write(QmltcOutputWrapper &code, const QmltcEnum &enumeration);
diff --git a/tools/qmltc/qmltccompiler.cpp b/tools/qmltc/qmltccompiler.cpp
index a2e1f47089..4654ecfd20 100644
--- a/tools/qmltc/qmltccompiler.cpp
+++ b/tools/qmltc/qmltccompiler.cpp
@@ -65,6 +65,7 @@ void QmltcCompiler::compile(const QmltcCompilerInfo &info)
     program.url = m_url;
     program.cppPath = m_info.outputCppFile;
     program.hPath = m_info.outputHFile;
+    program.outNamespace = m_info.outputNamespace;
     program.compiledTypes = compiledTypes;
     program.includes = m_visitor->cppIncludeFiles();
 
diff --git a/tools/qmltc/qmltccompiler.h b/tools/qmltc/qmltccompiler.h
index bdd56a7579..e59cc116f4 100644
--- a/tools/qmltc/qmltccompiler.h
+++ b/tools/qmltc/qmltccompiler.h
@@ -45,6 +45,7 @@ struct QmltcCompilerInfo
 {
     QString outputCppFile;
     QString outputHFile;
+    QString outputNamespace;
     QString resourcePath;
 };
 
diff --git a/tools/qmltc/qmltcoutputir.h b/tools/qmltc/qmltcoutputir.h
index e81caf14ed..c299f283a8 100644
--- a/tools/qmltc/qmltcoutputir.h
+++ b/tools/qmltc/qmltcoutputir.h
@@ -126,6 +126,7 @@ struct QmltcProgram
     QString url; // QML file url
     QString cppPath; // C++ output .cpp path
     QString hPath; // C++ output .h path
+    QString outNamespace;
     QSet<QString> includes; // non-default C++ include files
 
     QList<QmltcType> compiledTypes; // all QML types that are compiled to C++