QMimeTypeParser: use QStringBuilder more

Replace QString::arg() with QStringBuilder, use QStringLiteral
where appropriate, and remove it where it isn't (e.g. in
QStringBuilder expressions).

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

Change-Id: I2471c849db79f477677213f9a155053248800590
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

2 files changed, 7 insertions, 11 deletions

diff --git a/src/corelib/mimetypes/qmimemagicrule.cpp b/src/corelib/mimetypes/qmimemagicrule.cpp
index 06628fa323..528dca3ff5 100644
--- a/src/corelib/mimetypes/qmimemagicrule.cpp
+++ b/src/corelib/mimetypes/qmimemagicrule.cpp
@@ -234,7 +234,7 @@ QMimeMagicRule::QMimeMagicRule(const QString &type,
       m_matchFunction(nullptr)
 {
     if (m_type == Invalid)
-        *errorString = QStringLiteral("Type %s is not supported").arg(type);
+        *errorString = QLatin1String("Type ") + type + QLatin1String(" is not supported");
 
     // Parse for offset as "1" or "1:10"
     const int colonIndex = offsets.indexOf(QLatin1Char(':'));
@@ -249,7 +249,7 @@ QMimeMagicRule::QMimeMagicRule(const QString &type,
     if (m_value.isEmpty()) {
         m_type = Invalid;
         if (errorString)
-            *errorString = QLatin1String("Invalid empty magic rule value");
+            *errorString = QStringLiteral("Invalid empty magic rule value");
         return;
     }
 
@@ -259,8 +259,7 @@ QMimeMagicRule::QMimeMagicRule(const QString &type,
         if (!ok) {
             m_type = Invalid;
             if (errorString)
-                *errorString = QString::fromLatin1("Invalid magic rule value \"%1\"").arg(
-                        QString::fromLatin1(m_value));
+                *errorString = QLatin1String("Invalid magic rule value \"") + QLatin1String(m_value) + QLatin1Char('"');
             return;
         }
         m_numberMask = !m_mask.isEmpty() ? m_mask.toUInt(&ok, 0) : 0; // autodetect base
@@ -274,8 +273,7 @@ QMimeMagicRule::QMimeMagicRule(const QString &type,
             if (m_mask.size() < 4 || !m_mask.startsWith("0x")) {
                 m_type = Invalid;
                 if (errorString)
-                    *errorString = QString::fromLatin1("Invalid magic rule mask \"%1\"").arg(
-                            QString::fromLatin1(m_mask));
+                    *errorString = QLatin1String("Invalid magic rule mask \"") + QLatin1String(m_mask) + QLatin1Char('"');
                 return;
             }
             const QByteArray &tempMask = QByteArray::fromHex(QByteArray::fromRawData(
@@ -283,8 +281,7 @@ QMimeMagicRule::QMimeMagicRule(const QString &type,
             if (tempMask.size() != m_pattern.size()) {
                 m_type = Invalid;
                 if (errorString)
-                    *errorString = QString::fromLatin1("Invalid magic rule mask size \"%1\"").arg(
-                            QString::fromLatin1(m_mask));
+                    *errorString = QLatin1String("Invalid magic rule mask size \"") + QLatin1String(m_mask) + QLatin1Char('"');
                 return;
             }
             m_mask = tempMask;
diff --git a/src/corelib/mimetypes/qmimetypeparser.cpp b/src/corelib/mimetypes/qmimetypeparser.cpp
index b0d599fb0e..0751c1feed 100644
--- a/src/corelib/mimetypes/qmimetypeparser.cpp
+++ b/src/corelib/mimetypes/qmimetypeparser.cpp
@@ -205,7 +205,7 @@ bool QMimeTypeParserBase::parse(QIODevice *dev, const QString &fileName, QString
             case ParseMimeType: { // start parsing a MIME type name
                 const QString name = atts.value(QLatin1String(mimeTypeAttributeC)).toString();
                 if (name.isEmpty()) {
-                    reader.raiseError(QString::fromLatin1("Missing '%1'-attribute").arg(QString::fromLatin1(mimeTypeAttributeC)));
+                    reader.raiseError(QStringLiteral("Missing 'type'-attribute"));
                 } else {
                     data.name = name;
                 }
@@ -282,8 +282,7 @@ bool QMimeTypeParserBase::parse(QIODevice *dev, const QString &fileName, QString
                 break;
             }
             case ParseError:
-                reader.raiseError(QString::fromLatin1("Unexpected element <%1>").
-                                  arg(reader.name().toString()));
+                reader.raiseError(QLatin1String("Unexpected element <") + reader.name() + QLatin1Char('>'));
                 break;
             default:
                 break;