Qt: Allow users to explicitly tag files as mocable

This is helpful for declaring a QObject-derived class via a macro, in
which case the moc scanner will not help.

Fixes: QBS-1410
Change-Id: I19ee30eac670228686b5528888159220cf39abd3
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

8 files changed, 80 insertions, 1 deletions

diff --git a/doc/reference/modules/qt-core-module.qdoc b/doc/reference/modules/qt-core-module.qdoc
index 922b1889b..c8c3dc7de 100644
--- a/doc/reference/modules/qt-core-module.qdoc
+++ b/doc/reference/modules/qt-core-module.qdoc
@@ -109,6 +109,18 @@
         \li \c{*.ts}
         \li 1.0
         \li Files with this tag serve as inputs to the rule running the \c lrelease tool.
+    \row
+        \li \c{"mocable"}
+        \li -
+        \li 1.13
+        \li Use this tag to force \QBS to run \c moc on the respective files, even though
+            they do not contain \c Q_OBJECT or a related macro.
+    \row
+        \li \c{"unmocable"}
+        \li -
+        \li 1.2
+        \li Use this tag for files that \QBS should not run \c moc on, even though they contain
+            \c Q_OBJECT or a related macro.
     \endtable
 */
 
diff --git a/src/lib/corelib/buildgraph/qtmocscanner.cpp b/src/lib/corelib/buildgraph/qtmocscanner.cpp
index 121184648..dcdbd82a8 100644
--- a/src/lib/corelib/buildgraph/qtmocscanner.cpp
+++ b/src/lib/corelib/buildgraph/qtmocscanner.cpp
@@ -230,7 +230,17 @@ QScriptValue QtMocScanner::apply(QScriptEngine *engine, const Artifact *artifact
     bool hasPluginMetaDataMacro = false;
     const bool isHeaderFile = artifact->fileTags().contains(m_tags.hpp);
 
-    const RawScanResult scanResult = runScanner(m_cppScanner, artifact);
+    RawScanResult scanResult = runScanner(m_cppScanner, artifact);
+    if (scanResult.additionalFileTags.empty() && artifact->fileTags().contains("mocable")) {
+        if (isHeaderFile) {
+            scanResult.additionalFileTags.insert(m_tags.moc_hpp);
+        } else if (artifact->fileTags().contains(m_tags.cpp)
+                   || artifact->fileTags().contains(m_tags.cppCombine)
+                   || artifact->fileTags().contains(m_tags.objcpp)
+                   || artifact->fileTags().contains(m_tags.objcppCombine)) {
+            scanResult.additionalFileTags.insert(m_tags.moc_cpp);
+        }
+    }
     if (!scanResult.additionalFileTags.empty()) {
         if (isHeaderFile) {
             if (scanResult.additionalFileTags.contains(m_tags.moc_hpp))
diff --git a/tests/auto/blackbox/testdata-qt/forced-moc/createqtclass.h b/tests/auto/blackbox/testdata-qt/forced-moc/createqtclass.h
new file mode 100644
index 000000000..b57df6303
--- /dev/null
+++ b/tests/auto/blackbox/testdata-qt/forced-moc/createqtclass.h
@@ -0,0 +1,14 @@
+#ifndef CREATEQTCLASS_H
+#define CREATEQTCLASS_H
+
+#include <QObject>
+
+#define CREATE_QT_CLASS(className) \
+class className : public QObject \
+{ \
+    Q_OBJECT \
+public: \
+    Q_SIGNAL void mySignal(); \
+}
+
+#endif
diff --git a/tests/auto/blackbox/testdata-qt/forced-moc/forced-moc.qbs b/tests/auto/blackbox/testdata-qt/forced-moc/forced-moc.qbs
new file mode 100644
index 000000000..a59aaa28e
--- /dev/null
+++ b/tests/auto/blackbox/testdata-qt/forced-moc/forced-moc.qbs
@@ -0,0 +1,13 @@
+QtApplication {
+    files: "main.cpp"
+    Group {
+        name: "QObject service provider"
+        files: "createqtclass.h"
+        fileTags: ["hpp", "unmocable"]
+    }
+    Group {
+        name: "QObject service user"
+        files: "myqtclass.h"
+        fileTags: ["hpp", "mocable"]
+    }
+}
diff --git a/tests/auto/blackbox/testdata-qt/forced-moc/main.cpp b/tests/auto/blackbox/testdata-qt/forced-moc/main.cpp
new file mode 100644
index 000000000..e07c62984
--- /dev/null
+++ b/tests/auto/blackbox/testdata-qt/forced-moc/main.cpp
@@ -0,0 +1,14 @@
+#include "myqtclass.h"
+
+#include <QCoreApplication>
+#include <QDebug>
+#include <QTimer>
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication app(argc, argv);
+    MyQtClass c;
+    QObject::connect(&c, &MyQtClass::mySignal, [] { qDebug() << "Hello from slot"; qApp->quit(); });
+    QTimer::singleShot(0, &c, &MyQtClass::mySignal);
+    return app.exec();
+}
diff --git a/tests/auto/blackbox/testdata-qt/forced-moc/myqtclass.h b/tests/auto/blackbox/testdata-qt/forced-moc/myqtclass.h
new file mode 100644
index 000000000..d2557aab6
--- /dev/null
+++ b/tests/auto/blackbox/testdata-qt/forced-moc/myqtclass.h
@@ -0,0 +1,8 @@
+#ifndef MYQTCLASS_H
+#define MYQTCLASS_H
+
+#include "createqtclass.h"
+
+CREATE_QT_CLASS(MyQtClass);
+
+#endif
diff --git a/tests/auto/blackbox/tst_blackboxqt.cpp b/tests/auto/blackbox/tst_blackboxqt.cpp
index 6c013d918..128c61133 100644
--- a/tests/auto/blackbox/tst_blackboxqt.cpp
+++ b/tests/auto/blackbox/tst_blackboxqt.cpp
@@ -145,6 +145,13 @@ void TestBlackboxQt::dbusInterfaces()
     QCOMPARE(runQbs(), 0);
 }
 
+void TestBlackboxQt::forcedMoc()
+{
+    QDir::setCurrent(testDataDir + "/forced-moc");
+    QCOMPARE(runQbs(QbsRunParameters("run")), 0);
+    QVERIFY2(m_qbsStderr.contains("Hello from slot"), m_qbsStderr.constData());
+}
+
 void TestBlackboxQt::includedMocCpp()
 {
     QDir::setCurrent(testDataDir + "/included-moc-cpp");
diff --git a/tests/auto/blackbox/tst_blackboxqt.h b/tests/auto/blackbox/tst_blackboxqt.h
index 0240312a0..180f9e0c0 100644
--- a/tests/auto/blackbox/tst_blackboxqt.h
+++ b/tests/auto/blackbox/tst_blackboxqt.h
@@ -49,6 +49,7 @@ private slots:
     void createProject();
     void dbusAdaptors();
     void dbusInterfaces();
+    void forcedMoc();
     void includedMocCpp();
     void linkerVariant();
     void lrelease();