From b57fac818b7fe028dc61f1196cfda397233edffe Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Thu, 18 Jul 2024 22:57:10 +0200
Subject: Long live QDebug::toBytes()!
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I've seen over and over again how test authors are plagued by the
impedance mismatch between their 8-bit actual data and the result of
QString::toString() being in UTF-16. They invariably ditch their 8-bit
inputs and go to QString, but the mere fact that they start out with
8-bit input and then run into problems means we have a gaping API hole
here. QTest::toString() also suffers from this.

So add the option to a) construct a QDebug object over a QByteArray
(already supported by underlying QTextStream) and b) to stream into
QByteArray like toString() streams into QString.

Finally, make QTest::toString() use the new toBytes() function instead
of the old toString() one.

This saves 1% (91122→90248) in tst_tostring exeutable size on
optimized Linux AMD64 GCC 9 builds.

[ChangeLog][QtCore][QDebug] Added ctor from QByteArray* and a static
toBytes() function.

Change-Id: I2b021513d6427a1a961f39e751eaf4faaf527ba8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/io/qdebug.cpp | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

(limited to 'src/corelib/io/qdebug.cpp')

diff --git a/src/corelib/io/qdebug.cpp b/src/corelib/io/qdebug.cpp
index 600b8b13b80..1c6aecaaabb 100644
--- a/src/corelib/io/qdebug.cpp
+++ b/src/corelib/io/qdebug.cpp
@@ -1000,6 +1000,8 @@ QDebug &QDebug::resetFormat()
     \since 6.0
 
     \include qdebug-toString.qdocinc
+
+    \sa toBytes()
 */
 
 /*! \internal */
@@ -1013,6 +1015,26 @@ QString QDebug::toStringImpl(StreamTypeErased s, const void *obj)
     return result;
 }
 
+/*!
+    \fn template <class T> QByteArray QDebug::toBytes(const T &object)
+    \since 6.9
+
+    This is equivalent to \c{QDebug::toString(object).toUtf8()}, but more efficient.
+
+    \sa toString()
+*/
+
+/*! \internal */
+QByteArray QDebug::toBytesImpl(StreamTypeErased s, const void *obj)
+{
+    QByteArray result;
+    {
+        QDebug d(&result);
+        s(d.nospace(), obj);
+    }
+    return result;
+}
+
 /*!
     \fn template <class T> QDebug operator<<(QDebug debug, const QList<T> &list)
     \relates QDebug
-- 
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