Allow printf style for qCDebug, qCWarning, qCCritical macros

Add support for using qCDebug and friends in the 'printf style' way.
This allows an almost mechanical conversion of existing qDebug, qWarning,
qCritical macros, and allows avoiding the size overhead the streaming
style incurs (mostly due to inlined QDebug code).

To handle this gracefully we require variadic macros (part of
C++11/C99). For compilers not supporting variadic macros we fall back
to checking the category in QMessageLogger.

[ChangeLog][QtCore][Logging] Allow qCDebug macros to be used in a printf
style.

Change-Id: I5a8fb135dca504e1d621bb67bf4b2a50c73d41b9
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/auto/corelib/io/qloggingcategory/tst_qloggingcategory.cpp b/tests/auto/corelib/io/qloggingcategory/tst_qloggingcategory.cpp
index 50268f20a4..26f10385b3 100644
--- a/tests/auto/corelib/io/qloggingcategory/tst_qloggingcategory.cpp
+++ b/tests/auto/corelib/io/qloggingcategory/tst_qloggingcategory.cpp
@@ -376,16 +376,22 @@ private slots:
         buf = QStringLiteral("default.debug: Check debug with no filter active");
         qCDebug(defaultCategory) << "Check debug with no filter active";
         QCOMPARE(logMessage, buf);
+        qCDebug(defaultCategory, "Check debug with no filter active");
+        QCOMPARE(logMessage, buf);
 
         // Check default warning
         buf = QStringLiteral("default.warning: Check warning with no filter active");
         qCWarning(defaultCategory) << "Check warning with no filter active";
         QCOMPARE(logMessage, buf);
+        qCWarning(defaultCategory, "Check warning with no filter active");
+        QCOMPARE(logMessage, buf);
 
         // Check default critical
         buf = QStringLiteral("default.critical: Check critical with no filter active");
         qCCritical(defaultCategory) << "Check critical with no filter active";
         QCOMPARE(logMessage, buf);
+        qCCritical(defaultCategory, "Check critical with no filter active");
+        QCOMPARE(logMessage, buf);
 
 
         QLoggingCategory customCategory("custom");
@@ -412,6 +418,24 @@ private slots:
         qCDebug(customCategory) << "Check debug with filter active";
         QCOMPARE(logMessage, buf);
 
+        // Check different macro/category variants
+        buf = QStringLiteral("tst.log.debug: Check debug with no filter active");
+        qCDebug(TST_LOG) << "Check debug with no filter active";
+        QCOMPARE(logMessage, buf);
+        qCDebug(TST_LOG, "Check debug with no filter active");
+        QCOMPARE(logMessage, buf);
+        buf = QStringLiteral("tst.log.warning: Check warning with no filter active");
+        qCWarning(TST_LOG) << "Check warning with no filter active";
+        QCOMPARE(logMessage, buf);
+        qCWarning(TST_LOG, "Check warning with no filter active");
+        QCOMPARE(logMessage, buf);
+        buf = QStringLiteral("tst.log.critical: Check critical with no filter active");
+        qCCritical(TST_LOG) << "Check critical with no filter active";
+        QCOMPARE(logMessage, buf);
+        qCCritical(TST_LOG, "Check critical with no filter active");
+        QCOMPARE(logMessage, buf);
+
+
         // reset to default filter
         QLoggingCategory::installFilter(0);