Make enum values logging more terse()

By default enum class values are logged along with the qualifier; this
may or may not be desirable in a given setting. For JoinState(s) and
Membership(Mask) operator<< was overloaded to implicitly suppress
qualification; however, this is both overly sweeping and uses Qt's
internal API for the backend.

Instead, a new QDebug manipulator, terse(), is introduced, that does
the same as those operator<< overloads but on a per-invocation basis.
This makes it slightly more verbose to log enums but makes the QDebug
reconfiguration explicit and doesn't require to produce new overloads
every time a new enum ends up in logs. And it's built entirely on
the published Qt API, reusing the QDebugManip framework that Quotient
already has.

Also: operator<<(QDebug, QDebugManip) has been moved out of
the namespace to fix lookup issues when there's no prior
`using namespace Quotient`.

5 files changed, 25 insertions, 65 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 75966731..e65fdac4 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -636,7 +636,7 @@ void Connection::Private::consumeRoomData(SyncDataList&& roomDataList,
             }
             qWarning(MAIN) << "Room" << roomData.roomId
                            << "has just been forgotten but /sync returned it in"
-                           << roomData.joinState
+                           << terse << roomData.joinState
                            << "state - suspiciously fast turnaround";
         }
         if (auto* r = q->provideRoom(roomData.roomId, roomData.joinState)) {
@@ -1341,7 +1341,7 @@ void Connection::Private::removeRoom(const QString& roomId)
 {
     for (auto f : { false, true })
         if (auto r = roomMap.take({ roomId, f })) {
-            qCDebug(MAIN) << "Room" << r->objectName() << "in state"
+            qCDebug(MAIN) << "Room" << r->objectName() << "in state" << terse
                           << r->joinState() << "will be deleted";
             emit r->beforeDestruction(r);
             r->deleteLater();
diff --git a/lib/logging.h b/lib/logging.h
index 5a3ef6ea..5bf050a9 100644
--- a/lib/logging.h
+++ b/lib/logging.h
@@ -40,17 +40,15 @@ inline QDebug formatJson(QDebug debug_object)
     return debug_object.noquote();
 }
 
-/**
- * @brief A helper operator to facilitate usage of formatJson (and possibly
- * other manipulators)
- *
- * @param debug_object to output the json to
- * @param qdm a QDebug manipulator
- * @return a copy of debug_object that has its mode altered by qdm
- */
-inline QDebug operator<<(QDebug debug_object, QDebugManip qdm)
+//! Suppress full qualification of enums/QFlags when logging
+inline QDebug terse(QDebug dbg)
 {
-    return qdm(debug_object);
+    return
+#if QT_VERSION < QT_VERSION_CHECK(5, 13, 0)
+        dbg.setVerbosity(0), dbg;
+#else
+        dbg.verbosity(QDebug::MinimumVerbosity);
+#endif
 }
 
 inline qint64 profilerMinNsecs()
@@ -65,6 +63,19 @@ inline qint64 profilerMinNsecs()
 }
 } // namespace Quotient
 
+/**
+ * @brief A helper operator to facilitate usage of formatJson (and possibly
+ * other manipulators)
+ *
+ * @param debug_object to output the json to
+ * @param qdm a QDebug manipulator
+ * @return a copy of debug_object that has its mode altered by qdm
+ */
+inline QDebug operator<<(QDebug debug_object, Quotient::QDebugManip qdm)
+{
+    return qdm(debug_object);
+}
+
 inline QDebug operator<<(QDebug debug_object, const QElapsedTimer& et)
 {
     auto val = et.nsecsElapsed() / 1000;
diff --git a/lib/quotient_common.cpp b/lib/quotient_common.cpp
deleted file mode 100644
index 5d7a3027..00000000
--- a/lib/quotient_common.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-#include "quotient_common.h"
-
-#include <QtCore/QDebug>
-
-using namespace Quotient;
-
-template <typename Enum>
-inline QDebug suppressScopeAndDump(QDebug dbg, Enum e)
-{
-    // Suppress "Quotient::" prefix
-    QDebugStateSaver _dss(dbg);
-    dbg.setVerbosity(0 /* QDebug::MinimumVerbosity since Qt 5.13 */);
-    return qt_QMetaEnum_debugOperator(dbg, std::underlying_type_t<Enum>(e),
-                                      qt_getEnumMetaObject(e),
-                                      qt_getEnumName(e));
-}
-
-template <typename Enum>
-inline QDebug suppressScopeAndDump(QDebug dbg, const QFlags<Enum>& f)
-{
-    // Suppress "Quotient::" prefix
-    QDebugStateSaver _dss(dbg);
-    dbg.setVerbosity(0 /* QDebug::MinimumVerbosity since Qt 5.13 */);
-    return qt_QMetaEnum_flagDebugOperator_helper(dbg, f);
-}
-
-QDebug operator<<(QDebug dbg, Membership m)
-{
-    return suppressScopeAndDump(dbg, m);
-}
-
-QDebug operator<<(QDebug dbg, MembershipMask mm)
-{
-    return suppressScopeAndDump(dbg, mm) << ")";
-}
-
-QDebug operator<<(QDebug dbg, JoinState js)
-{
-    return suppressScopeAndDump(dbg, js);
-}
-
-QDebug operator<<(QDebug dbg, JoinStates jss)
-{
-    return suppressScopeAndDump(dbg, jss) << ")";
-}
diff --git a/lib/quotient_common.h b/lib/quotient_common.h
index 3d8ace67..969ebe90 100644
--- a/lib/quotient_common.h
+++ b/lib/quotient_common.h
@@ -118,9 +118,3 @@ constexpr inline auto RoomTypeStrings = make_array(
 } // namespace Quotient
 Q_DECLARE_OPERATORS_FOR_FLAGS(Quotient::MembershipMask)
 Q_DECLARE_OPERATORS_FOR_FLAGS(Quotient::JoinStates)
-
-class QDebug;
-QDebug operator<<(QDebug dbg, Quotient::Membership m);
-QDebug operator<<(QDebug dbg, Quotient::MembershipMask m);
-QDebug operator<<(QDebug dbg, Quotient::JoinState js);
-QDebug operator<<(QDebug dbg, Quotient::JoinStates js);
diff --git a/lib/room.cpp b/lib/room.cpp
index a376238e..a2ec228a 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -461,7 +461,7 @@ Room::Room(Connection* connection, QString id, JoinState initialJoinState)
             emit baseStateLoaded();
         return this == r; // loadedRoomState fires only once per room
     });
-    qCDebug(STATE) << "New" << initialJoinState << "Room:" << id;
+    qCDebug(STATE) << "New" << terse << initialJoinState << "Room:" << id;
 }
 
 Room::~Room() { delete d; }
@@ -612,7 +612,7 @@ void Room::setJoinState(JoinState state)
     if (state == oldState)
         return;
     d->joinState = state;
-    qCDebug(STATE) << "Room" << id() << "changed state: " << oldState
+    qCDebug(STATE) << "Room" << id() << "changed state: " << terse << oldState
                    << "->" << state;
     emit joinStateChanged(oldState, state);
 }