Logging: Disable tracking of debug source info for release builds

Tracking the file, line, function means the information has to be stored
in the binaries, enlarging the size. It also might be a surprise to some
commercial customers that their internal file & function names are
'leaked'. Therefore we enable it for debug builds only.

[ChangeLog][QtCore][Logging] File, line, function information are not
recorded anymore for logging statements in release builds. Set
QT_MESSAGELOGCONTEXT explicitly to enable recording in all configurations.

Change-Id: I454bdb42bcf5b5a8de6507f29f2a61109dca9b91
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>

src/corelib/global/qlogging.cpp

@@ -174,6 +174,9 @@ Q_CORE_EXPORT bool qt_logging_to_console()
     The class provides information about the source code location a qDebug(), qWarning(),
     qCritical() or qFatal() message was generated.
 
+    \note By default, this information is recorded only in debug builds. You can overwrite
+    this explicitly by defining \c QT_MESSAGELOGCONTEXT or \c{QT_NO_MESSAGELOGCONTEXT}.
+
     \sa QMessageLogger, QtMessageHandler, qInstallMessageHandler()
 */
 
@@ -185,8 +188,9 @@ Q_CORE_EXPORT bool qt_logging_to_console()
 
     QMessageLogger is used to generate messages for the Qt logging framework. Usually one uses
     it through qDebug(), qWarning(), qCritical, or qFatal() functions,
-    which are actually macros that expand to QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).debug()
+    which are actually macros: For example qDebug() expands to
-    et al.
+    QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).debug()
+    for debug builds, and QMessageLogger(0, 0, 0).debug() for release builds.
 
     One example of direct use is to forward errors that stem from a scripting language, e.g. QML:
 

src/corelib/global/qlogging.h

@@ -124,13 +124,28 @@ private:
     QMessageLogContext context;
 };
 
-/*
+#if !defined(QT_MESSAGELOGCONTEXT) && !defined(QT_NO_MESSAGELOGCONTEXT)
-  qDebug, qWarning, qCritical, qFatal are redefined to automatically include context information
+#  if defined(QT_NO_DEBUG)
- */
+#    define QT_NO_MESSAGELOGCONTEXT
-#define qDebug QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).debug
+#  else
-#define qWarning QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).warning
+#    define QT_MESSAGELOGCONTEXT
-#define qCritical QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).critical
+#  endif
-#define qFatal QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO).fatal
+#endif
+
+#ifdef QT_MESSAGELOGCONTEXT
+  #define QT_MESSAGELOG_FILE __FILE__
+  #define QT_MESSAGELOG_LINE __LINE__
+  #define QT_MESSAGELOG_FUNC Q_FUNC_INFO
+#else
+  #define QT_MESSAGELOG_FILE 0
+  #define QT_MESSAGELOG_LINE 0
+  #define QT_MESSAGELOG_FUNC 0
+#endif
+
+#define qDebug QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).debug
+#define qWarning QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).warning
+#define qCritical QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).critical
+#define qFatal QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC).fatal
 
 #define QT_NO_QDEBUG_MACRO while (false) QMessageLogger().noDebug
 #define QT_NO_QWARNING_MACRO while (false) QMessageLogger().noDebug

src/corelib/io/qloggingcategory.h

@@ -110,15 +110,16 @@ private:
         static const QLoggingCategory category(__VA_ARGS__); \
         return category; \
     }
+
 #define qCDebug(category, ...) \
     for (bool qt_category_enabled = category().isDebugEnabled(); qt_category_enabled; qt_category_enabled = false) \
-        QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO, category().categoryName()).debug(__VA_ARGS__)
+        QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, category().categoryName()).debug(__VA_ARGS__)
 #define qCWarning(category, ...) \
     for (bool qt_category_enabled = category().isWarningEnabled(); qt_category_enabled; qt_category_enabled = false) \
-        QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO, category().categoryName()).warning(__VA_ARGS__)
+        QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, category().categoryName()).warning(__VA_ARGS__)
 #define qCCritical(category, ...) \
     for (bool qt_category_enabled = category().isCriticalEnabled(); qt_category_enabled; qt_category_enabled = false) \
-        QMessageLogger(__FILE__, __LINE__, Q_FUNC_INFO, category().categoryName()).critical(__VA_ARGS__)
+        QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, category().categoryName()).critical(__VA_ARGS__)
 
 #else // defined(Q_COMPILER_VARIADIC_MACROS) || defined(Q_MOC_RUN)
 

tests/auto/corelib/global/qlogging/app/app.pro

@@ -10,6 +10,7 @@ CONFIG += console
 
 SOURCES += main.cpp
 DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0
+DEFINES += QT_MESSAGELOGCONTEXT
 
 gcc:!mingw: QMAKE_LFLAGS += -rdynamic
 

tests/auto/corelib/global/qlogging/test/test.pro

@@ -5,5 +5,6 @@ TARGET = ../tst_qlogging
 QT = core testlib
 SOURCES = ../tst_qlogging.cpp
 
+DEFINES += QT_MESSAGELOGCONTEXT
 TEST_HELPER_INSTALLS = ../app/app
 DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0

tests/auto/corelib/io/qdebug/tst_qdebug.cpp

@@ -116,9 +116,13 @@ private:
  */
 void tst_QDebug::warningWithoutDebug() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     { qWarning() << "A qWarning() message"; }
-    QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtWarningMsg);
     QCOMPARE(s_msg, QString::fromLatin1("A qWarning() message"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -131,9 +135,13 @@ void tst_QDebug::warningWithoutDebug() const
  */
 void tst_QDebug::criticalWithoutDebug() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     { qCritical() << "A qCritical() message"; }
-    QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtCriticalMsg);
     QCOMPARE(s_msg, QString::fromLatin1("A qCritical() message"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -143,9 +151,13 @@ void tst_QDebug::criticalWithoutDebug() const
 
 void tst_QDebug::debugWithBool() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     { qDebug() << false << true; }
-    QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("false true"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -291,6 +303,8 @@ void tst_QDebug::stateSaver() const
 
 void tst_QDebug::veryLongWarningMessage() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     QString test;
     {
@@ -299,7 +313,9 @@ void tst_QDebug::veryLongWarningMessage() const
             test.append(part);
         qWarning("Test output:\n%s\nend", qPrintable(test));
     }
-    QString file = __FILE__; int line = __LINE__ - 2; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 3; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtWarningMsg);
     QCOMPARE(s_msg, QString::fromLatin1("Test output:\n")+test+QString::fromLatin1("\nend"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -309,13 +325,17 @@ void tst_QDebug::veryLongWarningMessage() const
 
 void tst_QDebug::qDebugQChar() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     {
         QDebug d = qDebug();
         d << QChar('f');
         d.nospace().noquote() << QChar('o') << QChar('o');
     }
-    QString file = __FILE__; int line = __LINE__ - 4; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 5; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("'f' oo"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -328,12 +348,16 @@ void tst_QDebug::qDebugQStringRef() const
 {
     /* Use a basic string. */
     {
+        QString file, function;
+        int line = 0;
         const QString in(QLatin1String("input"));
         const QStringRef inRef(&in);
 
         MessageHandlerSetter mhs(myMessageHandler);
         { qDebug() << inRef; }
-        QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+        file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
         QCOMPARE(s_msgType, QtDebugMsg);
         QCOMPARE(s_msg, QString::fromLatin1("\"input\""));
         QCOMPARE(QString::fromLatin1(s_file), file);
@@ -343,11 +367,16 @@ void tst_QDebug::qDebugQStringRef() const
 
     /* Use a null QStringRef. */
     {
+        QString file, function;
+        int line = 0;
+
         const QStringRef inRef;
 
         MessageHandlerSetter mhs(myMessageHandler);
         { qDebug() << inRef; }
-        QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+        file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
         QCOMPARE(s_msgType, QtDebugMsg);
         QCOMPARE(s_msg, QString::fromLatin1("\"\""));
         QCOMPARE(QString::fromLatin1(s_file), file);
@@ -358,13 +387,17 @@ void tst_QDebug::qDebugQStringRef() const
 
 void tst_QDebug::qDebugQLatin1String() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     {
         QDebug d = qDebug();
         d << QLatin1String("foo") << QLatin1String("") << QLatin1String("barbaz", 3);
         d.nospace().noquote() << QLatin1String("baz");
     }
-    QString file = __FILE__; int line = __LINE__ - 4; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 5; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("\"foo\" \"\" \"bar\" baz"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -374,13 +407,17 @@ void tst_QDebug::qDebugQLatin1String() const
 
 void tst_QDebug::qDebugQByteArray() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     {
         QDebug d = qDebug();
         d << QByteArrayLiteral("foo") << QByteArrayLiteral("") << QByteArray("barbaz", 3);
         d.nospace().noquote() << QByteArrayLiteral("baz");
     }
-    QString file = __FILE__; int line = __LINE__ - 4; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 5; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("\"foo\" \"\" \"bar\" baz"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -397,11 +434,15 @@ Q_DECLARE_FLAGS(TestFlags, TestEnum)
 
 void tst_QDebug::qDebugQFlags() const
 {
+    QString file, function;
+    int line = 0;
     QFlags<TestEnum> flags(Flag1 | Flag2);
 
     MessageHandlerSetter mhs(myMessageHandler);
     { qDebug() << flags; }
-    QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("QFlags(0x1|0x10)"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -412,9 +453,13 @@ void tst_QDebug::qDebugQFlags() const
 
 void tst_QDebug::textStreamModifiers() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     { qDebug() << hex << short(0xf) << int(0xf) << unsigned(0xf) << long(0xf) << qint64(0xf) << quint64(0xf); }
-    QString file = __FILE__; int line = __LINE__ - 1; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 2; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("f f f f f f"));
     QCOMPARE(QString::fromLatin1(s_file), file);
@@ -424,13 +469,17 @@ void tst_QDebug::textStreamModifiers() const
 
 void tst_QDebug::resetFormat() const
 {
+    QString file, function;
+    int line = 0;
     MessageHandlerSetter mhs(myMessageHandler);
     {
         QDebug d = qDebug();
         d.nospace().noquote() << hex <<  int(0xf);
         d.resetFormat() << int(0xf) << QStringLiteral("foo");
     }
-    QString file = __FILE__; int line = __LINE__ - 4; QString function = Q_FUNC_INFO;
+#ifndef QT_NO_MESSAGELOGCONTEXT
+    file = __FILE__; line = __LINE__ - 5; function = Q_FUNC_INFO;
+#endif
     QCOMPARE(s_msgType, QtDebugMsg);
     QCOMPARE(s_msg, QString::fromLatin1("f15 \"foo\""));
     QCOMPARE(QString::fromLatin1(s_file), file);