include/QtCore/qloggingcategory.h

0001 // Copyright (C) 2016 The Qt Company Ltd.
0002 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
0003 // Qt-Security score:significant reason:default
0004
0005 #ifndef QLOGGINGCATEGORY_H
0006 #define QLOGGINGCATEGORY_H
0007
0008 #include <QtCore/qglobal.h>
0009 #include <QtCore/qdebug.h>
0010
0011 QT_BEGIN_NAMESPACE
0012
0013 class Q_CORE_EXPORT QLoggingCategory
0014 {
0015     Q_DISABLE_COPY(QLoggingCategory)
0016 public:
0017     explicit QLoggingCategory(const char *category, QtMsgType severityLevel = QtDebugMsg);
0018     ~QLoggingCategory();
0019
0020     bool isEnabled(QtMsgType type) const;
0021     void setEnabled(QtMsgType type, bool enable);
0022
0023     bool isDebugEnabled() const { return bools.enabledDebug.loadRelaxed(); }
0024     bool isInfoEnabled() const { return bools.enabledInfo.loadRelaxed(); }
0025     bool isWarningEnabled() const { return bools.enabledWarning.loadRelaxed(); }
0026     bool isCriticalEnabled() const { return bools.enabledCritical.loadRelaxed(); }
0027
0028     const char *categoryName() const { return name; }
0029
0030     // allows usage of both factory method and variable in qCX macros
0031     QLoggingCategory &operator()() { return *this; }
0032     const QLoggingCategory &operator()() const { return *this; }
0033
0034     static QLoggingCategory *defaultCategory();
0035
0036     typedef void (*CategoryFilter)(QLoggingCategory*);
0037     static CategoryFilter installFilter(CategoryFilter);
0038
0039     static void setFilterRules(const QString &rules);
0040
0041 private:
0042     Q_DECL_UNUSED_MEMBER void *d = nullptr; // reserved for future use
0043     const char *name = nullptr;
0044
0045     struct AtomicBools {
0046         QBasicAtomicInteger<bool> enabledDebug;
0047         QBasicAtomicInteger<bool> enabledWarning;
0048         QBasicAtomicInteger<bool> enabledCritical;
0049         QBasicAtomicInteger<bool> enabledInfo;
0050     };
0051     union {
0052         AtomicBools bools;
0053         QBasicAtomicInt enabled;
0054     };
0055     Q_DECL_UNUSED_MEMBER bool placeholder[4]; // reserved for future use
0056
0057     QT_DEFINE_TAG_STRUCT(UnregisteredInitialization);
0058     explicit constexpr QLoggingCategory(UnregisteredInitialization, const char *category) noexcept;
0059     friend class QLoggingRegistry;
0060 };
0061
0062 namespace { // allow different TUs to have different QT_NO_xxx_OUTPUT
0063 template <QtMsgType Which> struct QLoggingCategoryMacroHolder
0064 {
0065     static const bool IsOutputEnabled;
0066     const QLoggingCategory *category = nullptr;
0067     bool control = false;
0068     explicit QLoggingCategoryMacroHolder(const QLoggingCategory &cat)
0069     {
0070         if (IsOutputEnabled)
0071             init(cat);
0072     }
0073     void init(const QLoggingCategory &cat) noexcept
0074     {
0075         category = &cat;
0076         // same as:
0077         //  control = cat.isEnabled(Which);
0078         // but without an out-of-line call
0079         if constexpr (Which == QtDebugMsg) {
0080             control = cat.isDebugEnabled();
0081         } else if constexpr (Which == QtInfoMsg) {
0082             control = cat.isInfoEnabled();
0083         } else if constexpr (Which == QtWarningMsg) {
0084             control = cat.isWarningEnabled();
0085         } else if constexpr (Which == QtCriticalMsg) {
0086             control = cat.isCriticalEnabled();
0087         } else if constexpr (Which == QtFatalMsg) {
0088             control = true;
0089         } else {
0090             static_assert(QtPrivate::value_dependent_false<Which>(), "Unknown Qt message type");
0091         }
0092     }
0093     const char *name() const { return category->categoryName(); }
0094     explicit operator bool() const { return Q_UNLIKELY(control); }
0095 };
0096
0097 template <QtMsgType Which> const bool QLoggingCategoryMacroHolder<Which>::IsOutputEnabled = true;
0098 #if defined(QT_NO_DEBUG_OUTPUT)
0099 template <> const bool QLoggingCategoryMacroHolder<QtDebugMsg>::IsOutputEnabled = false;
0100 #endif
0101 #if defined(QT_NO_INFO_OUTPUT)
0102 template <> const bool QLoggingCategoryMacroHolder<QtInfoMsg>::IsOutputEnabled = false;
0103 #endif
0104 #if defined(QT_NO_WARNING_OUTPUT)
0105 template <> const bool QLoggingCategoryMacroHolder<QtWarningMsg>::IsOutputEnabled = false;
0106 #endif
0107 } // unnamed namespace
0108
0109 #define QT_DECLARE_EXPORTED_QT_LOGGING_CATEGORY(name, export_macro) \
0110     inline namespace QtPrivateLogging { export_macro const QLoggingCategory &name(); }
0111
0112 #ifdef QT_BUILDING_QT
0113 #define Q_DECLARE_LOGGING_CATEGORY(name) \
0114     inline namespace QtPrivateLogging { const QLoggingCategory &name(); }
0115
0116 #define Q_DECLARE_EXPORTED_LOGGING_CATEGORY(name, export_macro) \
0117     inline namespace QtPrivateLogging { \
0118     Q_DECL_DEPRECATED_X("Use QT_DECLARE_EXPORTED_QT_LOGGING_CATEGORY in Qt") \
0119     export_macro const QLoggingCategory &name(); \
0120     }
0121
0122 #define Q_LOGGING_CATEGORY_IMPL(name, ...) \
0123     const QLoggingCategory &name() \
0124     { \
0125         static const QLoggingCategory category(__VA_ARGS__); \
0126         return category; \
0127     }
0128
0129 #define Q_LOGGING_CATEGORY(name, ...) \
0130     inline namespace QtPrivateLogging { Q_LOGGING_CATEGORY_IMPL(name, __VA_ARGS__) } \
0131     Q_WEAK_OVERLOAD \
0132     Q_DECL_DEPRECATED_X("Use Q_STATIC_LOGGING_CATEGORY or add " \
0133                         "either Q_DECLARE_LOGGING_CATEGORY or " \
0134                         "QT_DECLARE_EXPORTED_QT_LOGGING_CATEGORY in a header") \
0135     const QLoggingCategory &name() { return QtPrivateLogging::name(); }
0136
0137 #define Q_STATIC_LOGGING_CATEGORY(name, ...) \
0138     static Q_LOGGING_CATEGORY_IMPL(name, __VA_ARGS__)
0139
0140 #else
0141 #define Q_DECLARE_LOGGING_CATEGORY(name) \
0142     const QLoggingCategory &name();
0143
0144 #define Q_DECLARE_EXPORTED_LOGGING_CATEGORY(name, export_macro) \
0145     export_macro Q_DECLARE_LOGGING_CATEGORY(name)
0146
0147 #define Q_LOGGING_CATEGORY(name, ...) \
0148     const QLoggingCategory &name() \
0149     { \
0150         static const QLoggingCategory category(__VA_ARGS__); \
0151         return category; \
0152     }
0153
0154 #define Q_STATIC_LOGGING_CATEGORY(name, ...) \
0155     static Q_LOGGING_CATEGORY(name, __VA_ARGS__)
0156 #endif
0157
0158 #define QT_MESSAGE_LOGGER_COMMON(category, level) \
0159     for (QLoggingCategoryMacroHolder<level> qt_category((category)()); qt_category; qt_category.control = false) \
0160         QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, qt_category.name())
0161
0162 #define qCDebug(category, ...) QT_MESSAGE_LOGGER_COMMON(category, QtDebugMsg).debug(__VA_ARGS__)
0163 #define qCInfo(category, ...) QT_MESSAGE_LOGGER_COMMON(category, QtInfoMsg).info(__VA_ARGS__)
0164 #define qCWarning(category, ...) QT_MESSAGE_LOGGER_COMMON(category, QtWarningMsg).warning(__VA_ARGS__)
0165 #define qCCritical(category, ...) QT_MESSAGE_LOGGER_COMMON(category, QtCriticalMsg).critical(__VA_ARGS__)
0166 #define qCFatal(category, ...) QT_MESSAGE_LOGGER_COMMON(category, QtFatalMsg).fatal(__VA_ARGS__)
0167
0168 QT_END_NAMESPACE
0169
0170 #endif // QLOGGINGCATEGORY_H