Logging: Add a macro for static logging category

Since name clashes between logging categories are so common, having a
way to explicitly avoid them is important. So far, we are depending on
internals of Q_LOGGING_CATEGORY to place the "static" in the right
location. That's less than ideal.

Task-number: QTBUG-67692
Change-Id: Ifeda5297d1d1220a57118b3bf7c7310e4ddd4f93
Reviewed-by: Tor Arne Vestbø <[email protected]>
Reviewed-by: Thiago Macieira <[email protected]>

11 files changed, 53 insertions, 8 deletions

diff --git a/src/corelib/io/qloggingcategory.cpp b/src/corelib/io/qloggingcategory.cpp
index 10763dd65a9..4e28c44e7b9 100644
--- a/src/corelib/io/qloggingcategory.cpp
+++ b/src/corelib/io/qloggingcategory.cpp
@@ -665,4 +665,43 @@ void QLoggingCategory::setFilterRules(const QString &rules)
     This macro must be used outside of a class or method.
 */
 
+/*!
+    \macro Q_STATIC_LOGGING_CATEGORY(name, string)
+    \sa Q_LOGGING_CATEGORY()
+    \relates QLoggingCategory
+    \since 6.9
+
+    Defines a static logging category \a name, and makes it configurable under
+    the \a string identifier. By default, all message types are enabled.
+
+    The logging category is created using the \c static qualifier so that you
+    can only access it in the same translation unit. This avoids accidental
+    symbol clashes.
+
+    The implicitly-defined QLoggingCategory object is created on first use,
+    in a thread-safe manner.
+
+    This macro must be used outside of a class or method.
+*/
+
+/*!
+    \macro Q_STATIC_LOGGING_CATEGORY(name, string, msgType)
+    \sa Q_LOGGING_CATEGORY()
+    \relates QLoggingCategory
+    \since 6.9
+
+    Defines a static logging category \a name, and makes it configurable under
+    the \a string identifier. By default, messages of QtMsgType \a msgType and
+    more severe are enabled, types with a lower severity are disabled.
+
+    The logging category is created using the \c static qualifier so that you
+    can only access it in the same translation unit. This avoids accidental
+    symbol clashes.
+
+    The implicitly-defined QLoggingCategory object is created on first use, in
+    a thread-safe manner.
+
+    This macro must be used outside of a class or method.
+*/
+
 QT_END_NAMESPACE
diff --git a/src/corelib/io/qloggingcategory.h b/src/corelib/io/qloggingcategory.h
index 7c32beea1aa..b8be7f6037c 100644
--- a/src/corelib/io/qloggingcategory.h
+++ b/src/corelib/io/qloggingcategory.h
@@ -116,6 +116,9 @@ template <> const bool QLoggingCategoryMacroHolder<QtWarningMsg>::IsOutputEnable
         return category; \
     }
 
+#define Q_STATIC_LOGGING_CATEGORY(name, ...) \
+    static Q_LOGGING_CATEGORY(name, __VA_ARGS__)
+
 #define QT_MESSAGE_LOGGER_COMMON(category, level) \
     for (QLoggingCategoryMacroHolder<level> qt_category((category)()); qt_category; qt_category.control = false) \
         QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, qt_category.name())
diff --git a/src/corelib/io/qloggingregistry_p.h b/src/corelib/io/qloggingregistry_p.h
index 92b96f0ba40..42738891f7f 100644
--- a/src/corelib/io/qloggingregistry_p.h
+++ b/src/corelib/io/qloggingregistry_p.h
@@ -39,6 +39,9 @@ QT_BEGIN_NAMESPACE
         return category;                                                            \
     }
 
+#define Q_STATIC_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(name, env, categoryName) \
+    static Q_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(name, env, categoryName)
+
 class Q_AUTOTEST_EXPORT QLoggingRule
 {
 public:
diff --git a/src/corelib/plugin/qelfparser_p.cpp b/src/corelib/plugin/qelfparser_p.cpp
index 7f6271cde49..78c9be0e563 100644
--- a/src/corelib/plugin/qelfparser_p.cpp
+++ b/src/corelib/plugin/qelfparser_p.cpp
@@ -35,7 +35,7 @@ static constexpr bool IncludeValidityChecks = true;
 #  define QELFPARSER_DEBUG
 #endif
 #if defined(QELFPARSER_DEBUG)
-static Q_LOGGING_CATEGORY(lcElfParser, "qt.core.plugin.elfparser")
+Q_STATIC_LOGGING_CATEGORY(lcElfParser, "qt.core.plugin.elfparser")
 #  define qEDebug       qCDebug(lcElfParser) << reinterpret_cast<const char16_t *>(error.errMsg->constData()) << ':'
 #else
 #  define qEDebug       if (false) {} else QNoDebug()
diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp
index e2d9a40cb4b..6486414d8c1 100644
--- a/src/corelib/plugin/qfactoryloader.cpp
+++ b/src/corelib/plugin/qfactoryloader.cpp
@@ -272,7 +272,7 @@ public:
 
 #if QT_CONFIG(library)
 
-static Q_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(lcFactoryLoader, "QT_DEBUG_PLUGINS",
+Q_STATIC_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(lcFactoryLoader, "QT_DEBUG_PLUGINS",
                                             "qt.core.plugin.factoryloader")
 
 namespace {
diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index a3ef8e3c525..8f1db7e4d40 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -55,7 +55,7 @@ static constexpr bool QtBuildIsDebug = true;
 #endif
 
 Q_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(qt_lcDebugPlugins, "QT_DEBUG_PLUGINS", "qt.core.plugin.loader")
-static Q_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(lcDebugLibrary, "QT_DEBUG_PLUGINS", "qt.core.library")
+Q_STATIC_LOGGING_CATEGORY_WITH_ENV_OVERRIDE(lcDebugLibrary, "QT_DEBUG_PLUGINS", "qt.core.library")
 
 /*!
     \class QLibrary
diff --git a/src/network/kernel/qdnslookup.cpp b/src/network/kernel/qdnslookup.cpp
index 1b4db7130b2..d8ac95b3ec9 100644
--- a/src/network/kernel/qdnslookup.cpp
+++ b/src/network/kernel/qdnslookup.cpp
@@ -24,7 +24,7 @@ QT_BEGIN_NAMESPACE
 
 using namespace Qt::StringLiterals;
 
-static Q_LOGGING_CATEGORY(lcDnsLookup, "qt.network.dnslookup", QtCriticalMsg)
+Q_STATIC_LOGGING_CATEGORY(lcDnsLookup, "qt.network.dnslookup", QtCriticalMsg)
 
 namespace {
 struct QDnsLookupThreadPool : QThreadPool
diff --git a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
index 976911d4583..77137f3b3c3 100644
--- a/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
+++ b/src/plugins/sqldrivers/odbc/qsql_odbc.cpp
@@ -27,7 +27,7 @@
 
 QT_BEGIN_NAMESPACE
 
-static Q_LOGGING_CATEGORY(lcOdbc, "qt.sql.odbc")
+Q_STATIC_LOGGING_CATEGORY(lcOdbc, "qt.sql.odbc")
 
 using namespace Qt::StringLiterals;
 
diff --git a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
index c574772fd77..05af02e1565 100644
--- a/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
+++ b/src/plugins/sqldrivers/sqlite/qsql_sqlite.cpp
@@ -39,7 +39,7 @@ Q_DECLARE_METATYPE(sqlite3_stmt*)
 
 QT_BEGIN_NAMESPACE
 
-static Q_LOGGING_CATEGORY(lcSqlite, "qt.sql.sqlite")
+Q_STATIC_LOGGING_CATEGORY(lcSqlite, "qt.sql.sqlite")
 
 using namespace Qt::StringLiterals;
 
diff --git a/src/sql/kernel/qsqldatabase.cpp b/src/sql/kernel/qsqldatabase.cpp
index c25fabf0a4b..e44533291a3 100644
--- a/src/sql/kernel/qsqldatabase.cpp
+++ b/src/sql/kernel/qsqldatabase.cpp
@@ -18,7 +18,7 @@
 
 QT_BEGIN_NAMESPACE
 
-static Q_LOGGING_CATEGORY(lcSqlDb, "qt.sql.qsqldatabase")
+Q_STATIC_LOGGING_CATEGORY(lcSqlDb, "qt.sql.qsqldatabase")
 
 using namespace Qt::StringLiterals;
 
diff --git a/src/sql/kernel/qsqlquery.cpp b/src/sql/kernel/qsqlquery.cpp
index 1ada7f9e27a..63f782fe222 100644
--- a/src/sql/kernel/qsqlquery.cpp
+++ b/src/sql/kernel/qsqlquery.cpp
@@ -20,7 +20,7 @@
 
 QT_BEGIN_NAMESPACE
 
-static Q_LOGGING_CATEGORY(lcSqlQuery, "qt.sql.qsqlquery")
+Q_STATIC_LOGGING_CATEGORY(lcSqlQuery, "qt.sql.qsqlquery")
 
 class QSqlQueryPrivate
 {