Use QString::splitRef() instead of QString::split()

Avoid string allocation where it seems feasible.

Change-Id: I61b23d4ef8a459f5aa77727a75f4e1d2b140da3b
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

11 files changed, 27 insertions, 24 deletions

diff --git a/src/plugins/cmakeprojectmanager/cmaketool.cpp b/src/plugins/cmakeprojectmanager/cmaketool.cpp
index 2cc0228656..e38ce68748 100644
--- a/src/plugins/cmakeprojectmanager/cmaketool.cpp
+++ b/src/plugins/cmakeprojectmanager/cmaketool.cpp
@@ -411,7 +411,7 @@ void CMakeTool::fetchVersionFromVersionOutput() const
         return;
 
     QRegularExpression versionLine("^cmake version ((\\d+).(\\d+).(\\d+).*)$");
-    for (const QString &line : response.stdOut().split('\n')) {
+    for (const QStringRef &line : response.stdOut().splitRef(QLatin1Char('\n'))) {
         QRegularExpressionMatch match = versionLine.match(line);
         if (!match.hasMatch())
             continue;
diff --git a/src/plugins/coreplugin/documentmanager.cpp b/src/plugins/coreplugin/documentmanager.cpp
index ef5ab7b776..9cf6a25a71 100644
--- a/src/plugins/coreplugin/documentmanager.cpp
+++ b/src/plugins/coreplugin/documentmanager.cpp
@@ -703,14 +703,14 @@ QString DocumentManager::getSaveFileName(const QString &title, const QString &pa
                 const int index = regExp.lastIndexIn(*selectedFilter);
                 if (index != -1) {
                     bool suffixOk = false;
-                    const QStringList &suffixes = regExp.cap(1).remove(QLatin1Char('*')).split(QLatin1Char(' '));
-                    foreach (const QString &suffix, suffixes)
+                    const QVector<QStringRef> suffixes = regExp.cap(1).remove(QLatin1Char('*')).splitRef(QLatin1Char(' '));
+                    foreach (const QStringRef &suffix, suffixes)
                         if (fileName.endsWith(suffix)) {
                             suffixOk = true;
                             break;
                         }
                     if (!suffixOk && !suffixes.isEmpty())
-                        fileName.append(suffixes.at(0));
+                        fileName.append(suffixes.at(0).toString());
                 }
             }
             if (QFile::exists(fileName)) {
diff --git a/src/plugins/debugger/breakpoint.cpp b/src/plugins/debugger/breakpoint.cpp
index 3313448fe4..448cbb7df5 100644
--- a/src/plugins/debugger/breakpoint.cpp
+++ b/src/plugins/debugger/breakpoint.cpp
@@ -228,8 +228,8 @@ bool BreakpointParameters::isCppBreakpoint() const
         if (qmlExtensionString.isEmpty())
             qmlExtensionString = ".qml;.js";
 
-        auto qmlFileExtensions = qmlExtensionString.split(";", QString::SkipEmptyParts);
-        foreach (QString extension, qmlFileExtensions) {
+        auto qmlFileExtensions = qmlExtensionString.splitRef(QLatin1Char(';'), QString::SkipEmptyParts);
+        foreach (QStringRef extension, qmlFileExtensions) {
             if (fileName.endsWith(extension, Qt::CaseInsensitive))
                 return false;
         }
diff --git a/src/plugins/debugger/cdb/cdbengine.cpp b/src/plugins/debugger/cdb/cdbengine.cpp
index 5afd9da1a1..e663e91fc8 100644
--- a/src/plugins/debugger/cdb/cdbengine.cpp
+++ b/src/plugins/debugger/cdb/cdbengine.cpp
@@ -2071,7 +2071,7 @@ void CdbEngine::ensureUsing32BitStackInWow64(const DebuggerResponse &response, c
 {
     // Parsing the header of the stack output to check which bitness
     // the cdb is currently using.
-    foreach (const QString &line, response.data.data().split('\n')) {
+    foreach (const QStringRef &line, response.data.data().splitRef(QLatin1Char('\n'))) {
         if (!line.startsWith("Child"))
             continue;
         if (line.startsWith("ChildEBP")) {
@@ -2909,7 +2909,8 @@ void CdbEngine::setupScripting(const DebuggerResponse &response)
         return;
     }
     const QString &verOutput = data.data();
-    const QStringList pythonVersion = verOutput.split(' ').first().split('.');
+    const QVector<QStringRef> pythonVersion =
+         verOutput.split(QLatin1Char(' ')).constFirst().splitRef(QLatin1Char('.'));
 
     bool ok = false;
     if (pythonVersion.size() == 3) {
diff --git a/src/plugins/debugger/debuggerprotocol.cpp b/src/plugins/debugger/debuggerprotocol.cpp
index 46f60b0954..45288cb83c 100644
--- a/src/plugins/debugger/debuggerprotocol.cpp
+++ b/src/plugins/debugger/debuggerprotocol.cpp
@@ -822,9 +822,9 @@ QString DebuggerCommand::argsToString() const
 
 DebuggerEncoding::DebuggerEncoding(const QString &data)
 {
-    const QStringList l = data.split(':');
+    const QVector<QStringRef> l = data.splitRef(QLatin1Char(':'));
 
-    const QString &t = l.at(0);
+    const QStringRef &t = l.at(0);
     if (t == "latin1") {
         type = HexEncodedLatin1;
         size = 1;
diff --git a/src/plugins/debugger/gdb/gdbengine.cpp b/src/plugins/debugger/gdb/gdbengine.cpp
index 8a8e649522..7716240c5a 100644
--- a/src/plugins/debugger/gdb/gdbengine.cpp
+++ b/src/plugins/debugger/gdb/gdbengine.cpp
@@ -3515,14 +3515,14 @@ void GdbEngine::handleRegisterListing(const DebuggerResponse &response)
     m_registers.clear();
     QStringList lines = response.consoleStreamOutput.split('\n');
     for (int i = 1; i < lines.size(); ++i) {
-        QStringList parts = QString(lines.at(i)).split(' ', QString::SkipEmptyParts);
+        const QVector<QStringRef> parts = QString(lines.at(i)).splitRef(' ', QString::SkipEmptyParts);
         if (parts.size() < 7)
             continue;
         int gdbRegisterNumber = parts.at(1).toInt();
         Register reg;
-        reg.name = parts.at(0);
+        reg.name = parts.at(0).toString();
         reg.size = parts.at(4).toInt();
-        reg.reportedType = parts.at(5);
+        reg.reportedType = parts.at(5).toString();
         m_registers[gdbRegisterNumber] = reg;
     }
 }
@@ -3895,7 +3895,7 @@ static SourcePathMap mergeStartParametersSourcePathMap(const DebuggerRunParamete
 void GdbEngine::startGdb(const QStringList &args)
 {
     const QString tests = QString::fromLocal8Bit(qgetenv("QTC_DEBUGGER_TESTS"));
-    foreach (const QString &test, tests.split(','))
+    foreach (const QStringRef &test, tests.splitRef(QLatin1Char(',')))
         m_testCases.insert(test.toInt());
     foreach (int test, m_testCases)
         showMessage("ENABLING TEST CASE: " + QString::number(test));
diff --git a/src/plugins/debugger/watchhandler.cpp b/src/plugins/debugger/watchhandler.cpp
index afd40dfdcc..e295492d05 100644
--- a/src/plugins/debugger/watchhandler.cpp
+++ b/src/plugins/debugger/watchhandler.cpp
@@ -2531,7 +2531,7 @@ void WatchHandler::addDumpers(const GdbMi &dumpers)
         DisplayFormats formats;
         formats.append(RawFormat);
         QString reportedFormats = dumper["formats"].data();
-        foreach (const QString &format, reportedFormats.split(',')) {
+        foreach (const QStringRef &format, reportedFormats.splitRef(',')) {
             if (int f = format.toInt())
                 formats.append(DisplayFormat(f));
         }
diff --git a/src/plugins/projectexplorer/abi.cpp b/src/plugins/projectexplorer/abi.cpp
index 9b42b97f6b..448f8cfe3f 100644
--- a/src/plugins/projectexplorer/abi.cpp
+++ b/src/plugins/projectexplorer/abi.cpp
@@ -352,7 +352,7 @@ Abi::Abi(const QString &abiString) :
     m_architecture(UnknownArchitecture), m_os(UnknownOS),
     m_osFlavor(UnknownFlavor), m_binaryFormat(UnknownFormat), m_wordWidth(0)
 {
-    QStringList abiParts = abiString.split(QLatin1Char('-'));
+    const QVector<QStringRef> abiParts = abiString.splitRef(QLatin1Char('-'));
     if (abiParts.count() >= 1) {
         if (abiParts.at(0) == QLatin1String("unknown"))
             m_architecture = UnknownArchitecture;
@@ -453,12 +453,14 @@ Abi::Abi(const QString &abiString) :
     }
 
     if (abiParts.count() >= 5) {
-        const QString &bits = abiParts.at(4);
+        const QStringRef &bits = abiParts.at(4);
         if (!bits.endsWith(QLatin1String("bit")))
             return;
 
         bool ok = false;
-        int bitCount = bits.leftRef(bits.count() - 3).toInt(&ok);
+        const QStringRef number =
+            bits.string()->midRef(bits.position(), bits.count() - 3);
+        const int bitCount = number.toInt(&ok);
         if (!ok)
             return;
         if (bitCount != 8 && bitCount != 16 && bitCount != 32 && bitCount != 64)
@@ -473,7 +475,7 @@ Abi Abi::abiFromTargetTriplet(const QString &triple)
     if (machine.isEmpty())
         return Abi();
 
-    QStringList parts = machine.split(QRegExp(QLatin1String("[ /-]")));
+    const QVector<QStringRef> parts = machine.splitRef(QRegExp(QLatin1String("[ /-]")));
 
     Abi::Architecture arch = Abi::UnknownArchitecture;
     Abi::OS os = Abi::UnknownOS;
@@ -482,7 +484,7 @@ Abi Abi::abiFromTargetTriplet(const QString &triple)
     unsigned char width = 0;
     int unknownCount = 0;
 
-    foreach (const QString &p, parts) {
+    for (const QStringRef &p : parts) {
         if (p == QLatin1String("unknown") || p == QLatin1String("pc") || p == QLatin1String("none")
                 || p == QLatin1String("gnu") || p == QLatin1String("uclibc")
                 || p == QLatin1String("86_64") || p == QLatin1String("redhat")
diff --git a/src/plugins/texteditor/generichighlighter/highlighter.cpp b/src/plugins/texteditor/generichighlighter/highlighter.cpp
index 877767f4c4..89150ac6d4 100644
--- a/src/plugins/texteditor/generichighlighter/highlighter.cpp
+++ b/src/plugins/texteditor/generichighlighter/highlighter.cpp
@@ -415,8 +415,8 @@ void Highlighter::changeContext(const QString &contextName,
                                 const bool assignCurrent)
 {
     if (contextName.startsWith(kPop)) {
-        QStringList list = contextName.split(kHash, QString::SkipEmptyParts);
-        for (int i = 0; i < list.size(); ++i) {
+        const int count = contextName.splitRef(kHash, QString::SkipEmptyParts).size();
+        for (int i = 0; i < count; ++i) {
             if (m_contexts.isEmpty()) {
                 throw HighlighterException(
                         QCoreApplication::translate("GenericHighlighter", "Reached empty context."));
diff --git a/src/plugins/texteditor/linenumberfilter.cpp b/src/plugins/texteditor/linenumberfilter.cpp
index f2315d4e11..1376972733 100644
--- a/src/plugins/texteditor/linenumberfilter.cpp
+++ b/src/plugins/texteditor/linenumberfilter.cpp
@@ -61,7 +61,7 @@ void LineNumberFilter::prepareSearch(const QString &entry)
 QList<LocatorFilterEntry> LineNumberFilter::matchesFor(QFutureInterface<LocatorFilterEntry> &, const QString &entry)
 {
     QList<LocatorFilterEntry> value;
-    QStringList lineAndColumn = entry.split(QLatin1Char(':'));
+    const QVector<QStringRef> lineAndColumn = entry.splitRef(QLatin1Char(':'));
     int sectionCount = lineAndColumn.size();
     int line = 0;
     int column = 0;
diff --git a/src/plugins/valgrind/callgrind/callgrindparser.cpp b/src/plugins/valgrind/callgrind/callgrindparser.cpp
index 9b072ee1b4..fec9f52c5c 100644
--- a/src/plugins/valgrind/callgrind/callgrindparser.cpp
+++ b/src/plugins/valgrind/callgrind/callgrindparser.cpp
@@ -327,7 +327,7 @@ void Parser::Private::parseHeader(QIODevice *device)
         } else if (line.startsWith("summary: ")) {
             QString values = getValue(line, 9);
             uint i = 0;
-            foreach (const QString &value, values.split(QLatin1Char(' '), QString::SkipEmptyParts))
+            foreach (const QStringRef &value, values.splitRef(QLatin1Char(' '), QString::SkipEmptyParts))
                 data->setTotalCost(i++, value.toULongLong());
         } else if (!line.trimmed().isEmpty()) {
             // handle line and exit parseHeader