qmltc: export generated classes

Add QMLTC_EXPORT_MACRO_NAME and QMLTC_EXPORT_FILE_NAME arguments to
qt_add_qml_module() that allows the user to export qmltc-generated code
from its library. The qmltc-generated code will include the header-file
specified in QMLTC_EXPORT_FILE_NAME and will be exported with the macro
specified by QMLTC_EXPORT_MACRO_NAME.
Leave both options unspecified to not export the code generated by
qmltc.

Describe the options in the documentation and write a test to see if the
class really has an export macro in the generated code:
1) tst_qmltc_qprocess will test if the macro and the header are correctly
inserted in the generated code.
2) tst_qmltc_{no,}diskcache will test if the generated code can still be
   used from a static library.

Fixes: QTBUG-106840
Task-number: QTBUG-96040
Change-Id: I554f03bcdf043e8114e42f51a7289a5c00de4f89
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

6 files changed, 81 insertions, 0 deletions

diff --git a/tests/auto/qml/qmltc/CMakeLists.txt b/tests/auto/qml/qmltc/CMakeLists.txt
index 4b86a6c018..1b7fbf6ee1 100644
--- a/tests/auto/qml/qmltc/CMakeLists.txt
+++ b/tests/auto/qml/qmltc/CMakeLists.txt
@@ -3,6 +3,7 @@
 
 add_subdirectory(QmltcTests)
 add_subdirectory(NamespaceTest/Subfolder)
+add_subdirectory(QmltcExportedTests)
 
 set(test_sources
     nameconflict.h nameconflict.cpp
@@ -18,6 +19,8 @@ set(qmltc_module_libs
     #   automatic type registration that comes from the plugin)
     qmltc_test_moduleplugin
     qmltc_namespace_test_module
+    qmltc_exported_tests_module
+    qmltc_exported_tests_moduleplugin
 )
 qt_internal_add_test(tst_qmltc_diskcache
     SOURCES ${test_sources}
diff --git a/tests/auto/qml/qmltc/QmltcExportedTests/CMakeLists.txt b/tests/auto/qml/qmltc/QmltcExportedTests/CMakeLists.txt
new file mode 100644
index 0000000000..1e1454baff
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcExportedTests/CMakeLists.txt
@@ -0,0 +1,30 @@
+# Copyright (C) 2023 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+qt_add_library(qmltc_exported_tests_module STATIC)
+qt_autogen_tools_initial_setup(qmltc_exported_tests_module)
+
+include(GenerateExportHeader)
+generate_export_header(qmltc_exported_tests_module)
+
+set(common_libraries
+    Qt::QuickPrivate
+)
+
+target_link_libraries(qmltc_exported_tests_module PUBLIC ${common_libraries})
+
+qt6_add_qml_module(qmltc_exported_tests_module
+    URI QmltcExportedTests
+    AUTO_RESOURCE_PREFIX
+    QML_FILES
+        HelloExportedWorld.qml
+    DEPENDENCIES
+        Qt::Quick
+    ENABLE_TYPE_COMPILER
+    QMLTC_EXPORT_DIRECTIVE "QMLTC_EXPORTED_TESTS_MODULE_EXPORT"
+    QMLTC_EXPORT_FILE_NAME "qmltc_exported_tests_module_export.h"
+)
+
+target_include_directories(qmltc_exported_tests_module PUBLIC ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR})
+
+qt_autogen_tools_initial_setup(qmltc_exported_tests_moduleplugin)
diff --git a/tests/auto/qml/qmltc/QmltcExportedTests/HelloExportedWorld.qml b/tests/auto/qml/qmltc/QmltcExportedTests/HelloExportedWorld.qml
new file mode 100644
index 0000000000..5e6886bced
--- /dev/null
+++ b/tests/auto/qml/qmltc/QmltcExportedTests/HelloExportedWorld.qml
@@ -0,0 +1,5 @@
+import QtQuick
+
+Item {
+    property string myString: "Hello! I should be exported by qmltc"
+}
diff --git a/tests/auto/qml/qmltc/tst_qmltc.cpp b/tests/auto/qml/qmltc/tst_qmltc.cpp
index 1fa4030642..381701991e 100644
--- a/tests/auto/qml/qmltc/tst_qmltc.cpp
+++ b/tests/auto/qml/qmltc/tst_qmltc.cpp
@@ -77,6 +77,7 @@
 #include "repeatercrash.h"
 #include "aliases.h"
 #include "inlinecomponentsfromdifferentfiles.h"
+#include "helloexportedworld.h"
 
 #include "testprivateproperty.h"
 #include "singletons.h"
@@ -3208,4 +3209,11 @@ void tst_qmltc::namespacedName()
     Q_UNUSED(t);
 }
 
+void tst_qmltc::checkExportsAreCompiling()
+{
+    QQmlEngine e;
+    QmltcExportedTests::HelloExportedWorld w(&e);
+    QCOMPARE(w.myString(), u"Hello! I should be exported by qmltc"_s);
+}
+
 QTEST_MAIN(tst_qmltc)
diff --git a/tests/auto/qml/qmltc/tst_qmltc.h b/tests/auto/qml/qmltc/tst_qmltc.h
index af084dcc01..f00a172522 100644
--- a/tests/auto/qml/qmltc/tst_qmltc.h
+++ b/tests/auto/qml/qmltc/tst_qmltc.h
@@ -93,4 +93,5 @@ private slots:
     void constSignalParameters();
     void cppNamespaces();
     void namespacedName();
+    void checkExportsAreCompiling();
 };
diff --git a/tests/auto/qml/qmltc_qprocess/tst_qmltc_qprocess.cpp b/tests/auto/qml/qmltc_qprocess/tst_qmltc_qprocess.cpp
index 7f12f29342..f0b99fcdf0 100644
--- a/tests/auto/qml/qmltc_qprocess/tst_qmltc_qprocess.cpp
+++ b/tests/auto/qml/qmltc_qprocess/tst_qmltc_qprocess.cpp
@@ -51,6 +51,7 @@ private slots:
     void topLevelComponent();
     void dashesInFilename();
     void invalidSignalHandlers();
+    void exports();
 };
 
 #ifndef TST_QMLTC_QPROCESS_RESOURCES
@@ -261,5 +262,38 @@ void tst_qmltc_qprocess::invalidSignalHandlers()
     }
 }
 
+static QString fileToString(const QString &path)
+{
+    QFile f(path);
+    if (f.open(QIODevice::ReadOnly))
+        return QString::fromLatin1(f.readAll());
+    return QString();
+}
+
+void tst_qmltc_qprocess::exports()
+{
+    const QString fileName = u"dummy.qml"_s;
+    QStringList extraArgs;
+    extraArgs << "--export"
+              << "MYLIB_EXPORT_MACRO"
+              << "--exportInclude"
+              << "exportheader.h";
+    const auto errors = runQmltc(fileName, true, extraArgs);
+
+    const QString headerName = m_tmpPath + u"/"_s + QFileInfo(fileName).baseName() + u".h"_s;
+    const QString header = fileToString(headerName);
+    const QString implementationName =
+            m_tmpPath + u"/"_s + QFileInfo(fileName).baseName() + u".cpp"_s;
+    const QString implementation = fileToString(implementationName);
+
+    QCOMPARE(errors.size(), 0);
+
+    QVERIFY(header.contains(u"class MYLIB_EXPORT_MACRO dummy : public QObject\n"_s));
+    QVERIFY(!implementation.contains(u"MYLIB_EXPORT_MACRO"_s));
+
+    QVERIFY(header.contains(u"#include \"exportheader.h\"\n"_s));
+    QVERIFY(!implementation.contains(u"exportheader.h"_s));
+}
+
 QTEST_MAIN(tst_qmltc_qprocess)
 #include "tst_qmltc_qprocess.moc"