QtCore: use printf-style qWarning/qDebug where possible (I)

The printf-style version of QDebug expands to a lot less code than the
std::ostream-style version. Of course, you pay in type safety (but
compilers warn about it these days), you cannot stream complex Qt
types and streaming QStrings is awkward, but in many cases you
actually improve on readability.

But the main reason is that something that's not supposed to be
executed under normal operation has no business bloating executable
code size.

This is not an attempt at converting all qWarnings() to printf-style,
only the low-hanging fruit.

In this first part, replace
   qWarning() << ""
with
   qWarning("...").

Saves ~750b in text size on optimized GCC 5.3 AMD64 builds.

Change-Id: I8bf3e46cd5a6b2cae0ceb3e355a50f61925c63d3
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

15 files changed, 37 insertions, 37 deletions

diff --git a/src/corelib/io/qfilesystemwatcher.cpp b/src/corelib/io/qfilesystemwatcher.cpp
index e26d412cf9..8b11830fbe 100644
--- a/src/corelib/io/qfilesystemwatcher.cpp
+++ b/src/corelib/io/qfilesystemwatcher.cpp
@@ -317,11 +317,11 @@ QStringList QFileSystemWatcher::addPaths(const QStringList &paths)
         // Autotest override case - use the explicitly selected engine only
         const QStringRef forceName = on.midRef(26);
         if(forceName == QLatin1String("poller")) {
-            qDebug() << "QFileSystemWatcher: skipping native engine, using only polling engine";
+            qDebug("QFileSystemWatcher: skipping native engine, using only polling engine");
             d_func()->initPollerEngine();
             engine = d->poller;
         } else if(forceName == QLatin1String("native")) {
-            qDebug() << "QFileSystemWatcher: skipping polling engine, using only native engine";
+            qDebug("QFileSystemWatcher: skipping polling engine, using only native engine");
             engine = d->native;
         }
     }
diff --git a/src/corelib/io/qfilesystemwatcher_inotify.cpp b/src/corelib/io/qfilesystemwatcher_inotify.cpp
index 791429cc5a..5564bc7dca 100644
--- a/src/corelib/io/qfilesystemwatcher_inotify.cpp
+++ b/src/corelib/io/qfilesystemwatcher_inotify.cpp
@@ -344,7 +344,7 @@ QStringList QInotifyFileSystemWatcherEngine::removePaths(const QStringList &path
 
 void QInotifyFileSystemWatcherEngine::readFromInotify()
 {
-    // qDebug() << "QInotifyFileSystemWatcherEngine::readFromInotify";
+    // qDebug("QInotifyFileSystemWatcherEngine::readFromInotify");
 
     int buffSize = 0;
     ioctl(inotifyFd, FIONREAD, (char *) &buffSize);
diff --git a/src/corelib/itemmodels/qsortfilterproxymodel.cpp b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
index dc159c8f7c..18cb49d483 100644
--- a/src/corelib/itemmodels/qsortfilterproxymodel.cpp
+++ b/src/corelib/itemmodels/qsortfilterproxymodel.cpp
@@ -376,7 +376,7 @@ QModelIndex QSortFilterProxyModelPrivate::proxy_to_source(const QModelIndex &pro
     if (!proxy_index.isValid())
         return QModelIndex(); // for now; we may want to be able to set a root index later
     if (proxy_index.model() != q_func()) {
-        qWarning() << "QSortFilterProxyModel: index from wrong model passed to mapToSource";
+        qWarning("QSortFilterProxyModel: index from wrong model passed to mapToSource");
         Q_ASSERT(!"QSortFilterProxyModel: index from wrong model passed to mapToSource");
         return QModelIndex();
     }
@@ -394,7 +394,7 @@ QModelIndex QSortFilterProxyModelPrivate::source_to_proxy(const QModelIndex &sou
     if (!source_index.isValid())
         return QModelIndex(); // for now; we may want to be able to set a root index later
     if (source_index.model() != model) {
-        qWarning() << "QSortFilterProxyModel: index from wrong model passed to mapFromSource";
+        qWarning("QSortFilterProxyModel: index from wrong model passed to mapFromSource");
         Q_ASSERT(!"QSortFilterProxyModel: index from wrong model passed to mapFromSource");
         return QModelIndex();
     }
diff --git a/src/corelib/json/qjsondocument.cpp b/src/corelib/json/qjsondocument.cpp
index 1fde69ecf6..b2fa16d22a 100644
--- a/src/corelib/json/qjsondocument.cpp
+++ b/src/corelib/json/qjsondocument.cpp
@@ -184,7 +184,7 @@ QJsonDocument &QJsonDocument::operator =(const QJsonDocument &other)
 QJsonDocument QJsonDocument::fromRawData(const char *data, int size, DataValidation validation)
 {
     if (quintptr(data) & 3) {
-        qWarning() <<"QJsonDocument::fromRawData: data has to have 4 byte alignment";
+        qWarning("QJsonDocument::fromRawData: data has to have 4 byte alignment");
         return QJsonDocument();
     }
 
diff --git a/src/corelib/json/qjsonparser.cpp b/src/corelib/json/qjsonparser.cpp
index 9bafcc4c5f..04bdb57d6b 100644
--- a/src/corelib/json/qjsonparser.cpp
+++ b/src/corelib/json/qjsonparser.cpp
@@ -300,7 +300,7 @@ QJsonDocument Parser::parse(QJsonParseError *error)
 {
 #ifdef PARSER_DEBUG
     indent = 0;
-    qDebug() << ">>>>> parser begin";
+    qDebug(">>>>> parser begin");
 #endif
     // allocate some space
     dataLength = qMax(end - json, (ptrdiff_t) 256);
@@ -346,7 +346,7 @@ QJsonDocument Parser::parse(QJsonParseError *error)
 
 error:
 #ifdef PARSER_DEBUG
-    qDebug() << ">>>>> parser error";
+    qDebug(">>>>> parser error");
 #endif
     if (error) {
         error->offset = json - head;
diff --git a/src/corelib/kernel/qppsobject.cpp b/src/corelib/kernel/qppsobject.cpp
index 5990deb9c3..dbff997c88 100644
--- a/src/corelib/kernel/qppsobject.cpp
+++ b/src/corelib/kernel/qppsobject.cpp
@@ -72,7 +72,7 @@ public:
     {
         int fd = qt_safe_open("/pps/.all", O_RDONLY);
         if (fd == -1) {
-            qWarning() << "qppsobject.cpp: qt_safe_open failed";
+            qWarning("qppsobject.cpp: qt_safe_open failed");
             value = -1;
         }
 
@@ -114,7 +114,7 @@ QPpsAttributeMap QPpsObjectPrivate::decode(const QByteArray &rawData, bool *ok)
         // no need to check ok in this case
         attributeMap = decodeObject(&decoder, ok);
     } else {
-        qWarning() << "QPpsObjectPrivate::decode: pps_decoder_initialize failed";
+        qWarning("QPpsObjectPrivate::decode: pps_decoder_initialize failed");
         *ok = false;
     }
 
@@ -162,7 +162,7 @@ QPpsAttribute QPpsObjectPrivate::decodeString(pps_decoder_t *decoder)
     pps_decoder_error_t error = pps_decoder_get_string(decoder, 0, &value);
 
     if (error != PPS_DECODER_OK) {
-        qWarning() << "QPpsObjectPrivate::decodeString: PPS_DECODER_GET_STRING failed";
+        qWarning("QPpsObjectPrivate::decodeString: PPS_DECODER_GET_STRING failed");
         return QPpsAttribute();
     }
 
@@ -189,19 +189,19 @@ QPpsAttribute QPpsObjectPrivate::decodeNumber(pps_decoder_t *decoder)
         case PPS_DECODER_CONVERSION_FAILED:
             error = pps_decoder_get_int64(decoder, 0, &llValue);
             if (error != PPS_DECODER_OK) {
-                qWarning() << "QPpsObjectPrivate::decodeNumber: failed to decode integer";
+                qWarning("QPpsObjectPrivate::decodeNumber: failed to decode integer");
                 return QPpsAttribute();
             }
             flags = readFlags(decoder);
             return QPpsAttributePrivate::createPpsAttribute(llValue, flags);
         default:
-            qWarning() << "QPpsObjectPrivate::decodeNumber: pps_decoder_get_int failed";
+            qWarning("QPpsObjectPrivate::decodeNumber: pps_decoder_get_int failed");
             return QPpsAttribute();
         }
     } else {
         pps_decoder_error_t error = pps_decoder_get_double(decoder, 0, &dValue);
         if (error != PPS_DECODER_OK) {
-            qWarning() << "QPpsObjectPrivate::decodeNumber: pps_decoder_get_double failed";
+            qWarning("QPpsObjectPrivate::decodeNumber: pps_decoder_get_double failed");
             return QPpsAttribute();
         }
         flags = readFlags(decoder);
@@ -215,7 +215,7 @@ QPpsAttribute QPpsObjectPrivate::decodeBool(pps_decoder_t *decoder)
     pps_decoder_error_t error = pps_decoder_get_bool(decoder, 0, &value);
 
     if (error != PPS_DECODER_OK) {
-        qWarning() << "QPpsObjectPrivate::decodeBool: pps_decoder_get_bool failed";
+        qWarning("QPpsObjectPrivate::decodeBool: pps_decoder_get_bool failed");
         return QPpsAttribute();
     }
 
@@ -278,7 +278,7 @@ QPpsAttribute QPpsObjectPrivate::decodeData(pps_decoder_t *decoder)
     case PPS_TYPE_NONE:
     case PPS_TYPE_UNKNOWN:
     default:
-        qWarning() << "QPpsObjectPrivate::decodeData: invalid pps_node_type";
+        qWarning("QPpsObjectPrivate::decodeData: invalid pps_node_type");
         return QPpsAttribute();
     }
 }
@@ -292,7 +292,7 @@ QPpsAttributeList QPpsObjectPrivate::decodeArray(pps_decoder_t *decoder, bool *o
         // Force movement to a specific index.
         pps_decoder_error_t error = pps_decoder_goto_index(decoder, i);
         if (error != PPS_DECODER_OK) {
-            qWarning() << "QPpsObjectPrivate::decodeArray: pps_decoder_goto_index failed";
+            qWarning("QPpsObjectPrivate::decodeArray: pps_decoder_goto_index failed");
             *ok = false;
             return QPpsAttributeList();
         }
@@ -319,7 +319,7 @@ QPpsAttributeMap QPpsObjectPrivate::decodeObject(pps_decoder_t *decoder, bool *o
         // Force movement to a specific index.
         pps_decoder_error_t error = pps_decoder_goto_index(decoder, i);
         if (error != PPS_DECODER_OK) {
-            qWarning() << "QPpsObjectPrivate::decodeObject: pps_decoder_goto_index failed";
+            qWarning("QPpsObjectPrivate::decodeObject: pps_decoder_goto_index failed");
             *ok = false;
             return QPpsAttributeMap();
         }
@@ -368,7 +368,7 @@ QVariant QPpsObjectPrivate::variantFromPpsAttribute(const QPpsAttribute &attribu
         return variantMapFromPpsAttributeMap(attribute.toMap());
     case QPpsAttribute::None:
     default:
-        qWarning() << "QPpsObjectPrivate::variantFromPpsAttribute: invalid attribute parameter";
+        qWarning("QPpsObjectPrivate::variantFromPpsAttribute: invalid attribute parameter");
         return QVariant();
     }
 }
@@ -385,7 +385,7 @@ QByteArray QPpsObjectPrivate::encode(const QVariantMap &ppsData, bool *ok)
         // The memory will be freed when pps_encoder_cleanup is called.
         rawData = pps_encoder_buffer(&encoder);
         if (!rawData) {
-            qWarning() << "QPpsObjectPrivate::encode: pps_encoder_buffer failed";
+            qWarning("QPpsObjectPrivate::encode: pps_encoder_buffer failed");
             *ok = false;
         }
     }
@@ -448,7 +448,7 @@ void QPpsObjectPrivate::encodeData(pps_encoder_t *encoder, const char *name, con
         errorFunction = QStringLiteral("pps_encoder_add_null");
         break;
     default:
-        qWarning() << "QPpsObjectPrivate::encodeData: the type of the parameter data is invalid";
+        qWarning("QPpsObjectPrivate::encodeData: the type of the parameter data is invalid");
         *ok = false;
         return;
     }
@@ -685,7 +685,7 @@ QByteArray QPpsObject::read(bool *ok)
 
     const int maxSize = ppsMaxSize->value;
     if (maxSize == -1) {
-        qWarning() << "QPpsObject::read: maxSize is equal to -1";
+        qWarning("QPpsObject::read: maxSize is equal to -1");
         safeAssign(ok, false);
         return QByteArray();
     }
diff --git a/src/corelib/kernel/qppsobjectprivate_p.h b/src/corelib/kernel/qppsobjectprivate_p.h
index 26d89ab7f0..e1d54e58de 100644
--- a/src/corelib/kernel/qppsobjectprivate_p.h
+++ b/src/corelib/kernel/qppsobjectprivate_p.h
@@ -105,7 +105,7 @@ inline bool QPpsObjectPrivate::decoderPush(pps_decoder_t *decoder, const char *n
 {
     pps_decoder_error_t error = pps_decoder_push(decoder, name);
     if (error != PPS_DECODER_OK) {
-        qWarning() << "QPpsObjectPrivate::decodeData: pps_decoder_push failed";
+        qWarning("QPpsObjectPrivate::decodeData: pps_decoder_push failed");
         return false;
     }
     return true;
@@ -115,7 +115,7 @@ inline bool QPpsObjectPrivate::decoderPop(pps_decoder_t *decoder)
 {
     pps_decoder_error_t error = pps_decoder_pop(decoder);
     if (error != PPS_DECODER_OK) {
-        qWarning() << "QPpsObjectPrivate::decodeData: pps_decoder_pop failed";
+        qWarning("QPpsObjectPrivate::decodeData: pps_decoder_pop failed");
         return false;
     }
     return true;
diff --git a/src/corelib/kernel/qsystemsemaphore_posix.cpp b/src/corelib/kernel/qsystemsemaphore_posix.cpp
index 76ab0d42eb..6137239467 100644
--- a/src/corelib/kernel/qsystemsemaphore_posix.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_posix.cpp
@@ -119,7 +119,7 @@ void QSystemSemaphorePrivate::cleanHandle()
         if (::sem_close(semaphore) == -1) {
             setErrorString(QLatin1String("QSystemSemaphore::cleanHandle (sem_close)"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-            qDebug() << QLatin1String("QSystemSemaphore::cleanHandle sem_close failed.");
+            qDebug("QSystemSemaphore::cleanHandle sem_close failed.");
 #endif
         }
         semaphore = SEM_FAILED;
@@ -129,7 +129,7 @@ void QSystemSemaphorePrivate::cleanHandle()
         if (::sem_unlink(QFile::encodeName(fileName).constData()) == -1 && errno != ENOENT) {
             setErrorString(QLatin1String("QSystemSemaphore::cleanHandle (sem_unlink)"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-            qDebug() << QLatin1String("QSystemSemaphore::cleanHandle sem_unlink failed.");
+            qDebug("QSystemSemaphore::cleanHandle sem_unlink failed.");
 #endif
         }
         createdSemaphore = false;
diff --git a/src/corelib/kernel/qsystemsemaphore_systemv.cpp b/src/corelib/kernel/qsystemsemaphore_systemv.cpp
index 69e1bf7705..f4fdfa5f58 100644
--- a/src/corelib/kernel/qsystemsemaphore_systemv.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_systemv.cpp
@@ -153,7 +153,7 @@ void QSystemSemaphorePrivate::cleanHandle()
             if (-1 == semctl(semaphore, 0, IPC_RMID, 0)) {
                 setErrorString(QLatin1String("QSystemSemaphore::cleanHandle"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-                qDebug() << QLatin1String("QSystemSemaphore::cleanHandle semctl failed.");
+                qDebug("QSystemSemaphore::cleanHandle semctl failed.");
 #endif
             }
             semaphore = -1;
diff --git a/src/corelib/kernel/qsystemsemaphore_win.cpp b/src/corelib/kernel/qsystemsemaphore_win.cpp
index ca31e9d59d..236e346afe 100644
--- a/src/corelib/kernel/qsystemsemaphore_win.cpp
+++ b/src/corelib/kernel/qsystemsemaphore_win.cpp
@@ -101,7 +101,7 @@ void QSystemSemaphorePrivate::cleanHandle()
 {
     if (semaphore && !CloseHandle(semaphore)) {
 #if defined QSYSTEMSEMAPHORE_DEBUG
-        qDebug() << QLatin1String("QSystemSemaphorePrivate::CloseHandle: sem failed");
+        qDebug("QSystemSemaphorePrivate::CloseHandle: sem failed");
 #endif
     }
     semaphore = 0;
@@ -116,7 +116,7 @@ bool QSystemSemaphorePrivate::modifySemaphore(int count)
         if (0 == ReleaseSemaphore(semaphore, count, 0)) {
             setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-            qDebug() << QLatin1String("QSystemSemaphore::modifySemaphore ReleaseSemaphore failed");
+            qDebug("QSystemSemaphore::modifySemaphore ReleaseSemaphore failed");
 #endif
             return false;
         }
@@ -128,7 +128,7 @@ bool QSystemSemaphorePrivate::modifySemaphore(int count)
 #endif
             setErrorString(QLatin1String("QSystemSemaphore::modifySemaphore"));
 #if defined QSYSTEMSEMAPHORE_DEBUG
-            qDebug() << QLatin1String("QSystemSemaphore::modifySemaphore WaitForSingleObject failed");
+            qDebug("QSystemSemaphore::modifySemaphore WaitForSingleObject failed");
 #endif
             return false;
         }
diff --git a/src/corelib/mimetypes/qmimeprovider.cpp b/src/corelib/mimetypes/qmimeprovider.cpp
index dd60c5af08..52b5327f54 100644
--- a/src/corelib/mimetypes/qmimeprovider.cpp
+++ b/src/corelib/mimetypes/qmimeprovider.cpp
@@ -559,7 +559,7 @@ QList<QMimeType> QMimeBinaryProvider::allMimeTypes()
 void QMimeBinaryProvider::loadMimeTypePrivate(QMimeTypePrivate &data)
 {
 #ifdef QT_NO_XMLSTREAMREADER
-    qWarning() << "Cannot load mime type since QXmlStreamReader is not available.";
+    qWarning("Cannot load mime type since QXmlStreamReader is not available.");
     return;
 #else
     if (data.loaded)
diff --git a/src/corelib/tools/qcollator_macx.cpp b/src/corelib/tools/qcollator_macx.cpp
index 207b5bb2b1..b4d93e58d4 100644
--- a/src/corelib/tools/qcollator_macx.cpp
+++ b/src/corelib/tools/qcollator_macx.cpp
@@ -55,7 +55,7 @@ void QCollatorPrivate::init()
     LocaleRef localeRef;
     int rc = LocaleRefFromLocaleString(locale.bcp47Name().toLocal8Bit(), &localeRef);
     if (rc != 0)
-        qWarning() << "couldn't initialize the locale";
+        qWarning("couldn't initialize the locale");
 
     UInt32 options = 0;
 
@@ -73,7 +73,7 @@ void QCollatorPrivate::init()
         &collator
     );
     if (status != 0)
-        qWarning() << "Couldn't initialize the collator";
+        qWarning("Couldn't initialize the collator");
 
     dirty = false;
 }
diff --git a/src/corelib/tools/qcollator_win.cpp b/src/corelib/tools/qcollator_win.cpp
index 30e358c3f9..fcd8d069eb 100644
--- a/src/corelib/tools/qcollator_win.cpp
+++ b/src/corelib/tools/qcollator_win.cpp
@@ -73,7 +73,7 @@ void QCollatorPrivate::init()
         if (QSysInfo::windowsVersion() >= QSysInfo::WV_WINDOWS7)
             collator |= SORT_DIGITSASNUMBERS;
         else
-            qWarning() << "Numeric sorting unsupported on Windows versions older than Windows 7.";
+            qWarning("Numeric sorting unsupported on Windows versions older than Windows 7.");
     }
 
     if (ignorePunctuation)
diff --git a/src/corelib/tools/qmap.h b/src/corelib/tools/qmap.h
index 7eec281957..9801878bdc 100644
--- a/src/corelib/tools/qmap.h
+++ b/src/corelib/tools/qmap.h
@@ -909,7 +909,7 @@ template <class Key, class T>
 void QMap<Key, T>::dump() const
 {
     const_iterator it = begin();
-    qDebug() << "map dump:";
+    qDebug("map dump:");
     while (it != end()) {
         const QMapNodeBase *n = it.i;
         int depth = 0;
@@ -922,7 +922,7 @@ void QMap<Key, T>::dump() const
                  << it.key() << it.value();
         ++it;
     }
-    qDebug() << "---------";
+    qDebug("---------");
 }
 #endif
 
diff --git a/src/corelib/tools/qtimeline.cpp b/src/corelib/tools/qtimeline.cpp
index dd6a4dbc56..adbc2900e3 100644
--- a/src/corelib/tools/qtimeline.cpp
+++ b/src/corelib/tools/qtimeline.cpp
@@ -131,7 +131,7 @@ void QTimeLinePrivate::setCurrentTime(int msecs)
         const int transitionframe = (direction == QTimeLine::Forward ? endFrame : startFrame);
         if (looping && !finished && transitionframe != currentFrame) {
 #ifdef QTIMELINE_DEBUG
-            qDebug() << "QTimeLinePrivate::setCurrentTime: transitionframe";
+            qDebug("QTimeLinePrivate::setCurrentTime: transitionframe");
 #endif
             emit q->frameChanged(transitionframe, QTimeLine::QPrivateSignal());
         }