overhaul process argument handling

get away from argument stringlists. instead, use native shell command
lines which support quoting/splitting, environment variable expansion
and redirections with well-understood semantics.

Task-number: QTCREATORBUG-542
Task-number: QTCREATORBUG-1564

82 files changed, 475 insertions, 453 deletions

diff --git a/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp b/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
index a7ed541148..0ae0833f57 100644
--- a/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp
@@ -243,7 +243,7 @@ CMakeBuildConfiguration *CMakeBuildConfigurationFactory::create(ProjectExplorer:
 
     MakeStep *cleanMakeStep = new MakeStep(cleanSteps);
     cleanSteps->insertStep(0, cleanMakeStep);
-    cleanMakeStep->setAdditionalArguments(QStringList() << "clean");
+    cleanMakeStep->setAdditionalArguments("clean");
     cleanMakeStep->setClean(true);
 
     CMakeOpenProjectWizard copw(cmtarget->cmakeProject()->projectManager(),
diff --git a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.cpp b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.cpp
index 56870530fb..6b1c4ba713 100644
--- a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.cpp
@@ -202,12 +202,12 @@ void CMakeOpenProjectWizard::setMsvcVersion(const QString &version)
     m_msvcVersion = version;
 }
 
-QStringList CMakeOpenProjectWizard::arguments() const
+QString CMakeOpenProjectWizard::arguments() const
 {
     return m_arguments;
 }
 
-void CMakeOpenProjectWizard::setArguments(const QStringList &args)
+void CMakeOpenProjectWizard::setArguments(const QString &args)
 {
     m_arguments = args;
 }
@@ -426,7 +426,6 @@ void CMakeRunPage::runCMake()
 {
     m_runCMake->setEnabled(false);
     m_argumentsLineEdit->setEnabled(false);
-    QStringList arguments = Utils::Environment::parseCombinedArgString(m_argumentsLineEdit->text());
     CMakeManager *cmakeManager = m_cmakeWizard->cmakeManager();
 
 #ifdef Q_OS_WIN
@@ -464,11 +463,11 @@ void CMakeRunPage::runCMake()
     m_output->clear();
 
     if (m_cmakeWizard->cmakeManager()->isCMakeExecutableValid()) {
-        m_cmakeProcess = new QProcess();
+        m_cmakeProcess = new Utils::QtcProcess();
         connect(m_cmakeProcess, SIGNAL(readyReadStandardOutput()), this, SLOT(cmakeReadyReadStandardOutput()));
         connect(m_cmakeProcess, SIGNAL(readyReadStandardError()), this, SLOT(cmakeReadyReadStandardError()));
         connect(m_cmakeProcess, SIGNAL(finished(int)), this, SLOT(cmakeFinished()));
-        cmakeManager->createXmlFile(m_cmakeProcess, arguments, m_cmakeWizard->sourceDirectory(), m_buildDirectory, env, generator);
+        cmakeManager->createXmlFile(m_cmakeProcess, m_argumentsLineEdit->text(), m_cmakeWizard->sourceDirectory(), m_buildDirectory, env, generator);
     } else {
         m_runCMake->setEnabled(true);
         m_argumentsLineEdit->setEnabled(true);
@@ -522,7 +521,7 @@ void CMakeRunPage::cmakeFinished()
     }
     m_cmakeProcess->deleteLater();
     m_cmakeProcess = 0;
-    m_cmakeWizard->setArguments(Utils::Environment::parseCombinedArgString(m_argumentsLineEdit->text()));
+    m_cmakeWizard->setArguments(m_argumentsLineEdit->text());
     //TODO Actually test that running cmake was finished, for setting this bool
     emit completeChanged();
 }
diff --git a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
index d38edd6b4b..d28b77a9a0 100644
--- a/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
+++ b/src/plugins/cmakeprojectmanager/cmakeopenprojectwizard.h
@@ -32,8 +32,8 @@
 
 #include <utils/environment.h>
 #include <utils/wizard.h>
+#include <utils/qtcprocess.h>
 
-#include <QtCore/QProcess>
 #include <QtGui/QPushButton>
 #include <QtGui/QComboBox>
 #include <QtGui/QLineEdit>
@@ -81,8 +81,8 @@ public:
     QString sourceDirectory() const;
     void setBuildDirectory(const QString &directory);
     CMakeManager *cmakeManager() const;
-    QStringList arguments() const;
-    void setArguments(const QStringList &args);
+    QString arguments() const;
+    void setArguments(const QString &args);
     Utils::Environment environment() const;
     QString msvcVersion() const;
     void setMsvcVersion(const QString &version);
@@ -93,7 +93,7 @@ private:
     CMakeManager *m_cmakeManager;
     QString m_buildDirectory;
     QString m_sourceDirectory;
-    QStringList m_arguments;
+    QString m_arguments;
     QString m_msvcVersion;
     bool m_creatingCbpFiles;
     Utils::Environment m_environment;
@@ -140,7 +140,7 @@ private:
     CMakeOpenProjectWizard *m_cmakeWizard;
     QPlainTextEdit *m_output;
     QPushButton *m_runCMake;
-    QProcess *m_cmakeProcess;
+    Utils::QtcProcess *m_cmakeProcess;
     QLineEdit *m_argumentsLineEdit;
     Utils::PathChooser *m_cmakeExecutable;
     QComboBox *m_generatorComboBox;
diff --git a/src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp b/src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp
index 2403846cd9..200d4037ce 100644
--- a/src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakeprojectmanager.cpp
@@ -32,6 +32,7 @@
 #include "cmakeproject.h"
 
 #include <utils/synchronousprocess.h>
+#include <utils/qtcprocess.h>
 
 #include <coreplugin/icore.h>
 #include <coreplugin/uniqueidmanager.h>
@@ -102,7 +103,7 @@ bool CMakeManager::hasCodeBlocksMsvcGenerator() const
 // we probably want the process instead of this function
 // cmakeproject then could even run the cmake process in the background, adding the files afterwards
 // sounds like a plan
-void CMakeManager::createXmlFile(QProcess *proc, const QStringList &arguments,
+void CMakeManager::createXmlFile(Utils::QtcProcess *proc, const QString &arguments,
                                  const QString &sourceDirectory, const QDir &buildDirectory,
                                  const Utils::Environment &env, const QString &generator)
 {
@@ -117,11 +118,16 @@ void CMakeManager::createXmlFile(QProcess *proc, const QStringList &arguments,
     QString buildDirectoryPath = buildDirectory.absolutePath();
     buildDirectory.mkpath(buildDirectoryPath);
     proc->setWorkingDirectory(buildDirectoryPath);
-    proc->setEnvironment(env.toStringList());
+    proc->setEnvironment(env);
 
     const QString srcdir = buildDirectory.exists(QLatin1String("CMakeCache.txt")) ?
                 QString(QLatin1Char('.')) : sourceDirectory;
-    proc->start(cmakeExecutable(), QStringList() << srcdir << arguments << generator);
+    QString args;
+    Utils::QtcProcess::addArg(&args, srcdir);
+    Utils::QtcProcess::addArgs(&args, arguments);
+    Utils::QtcProcess::addArg(&args, generator);
+    proc->setCommand(cmakeExecutable(), args);
+    proc->start();
 }
 
 QString CMakeManager::findCbpFile(const QDir &directory)
diff --git a/src/plugins/cmakeprojectmanager/cmakeprojectmanager.h b/src/plugins/cmakeprojectmanager/cmakeprojectmanager.h
index 9da4e120cc..44ecd271cd 100644
--- a/src/plugins/cmakeprojectmanager/cmakeprojectmanager.h
+++ b/src/plugins/cmakeprojectmanager/cmakeprojectmanager.h
@@ -44,6 +44,10 @@
 QT_FORWARD_DECLARE_CLASS(QProcess)
 QT_FORWARD_DECLARE_CLASS(QLabel)
 
+namespace Utils {
+class QtcProcess;
+}
+
 namespace CMakeProjectManager {
 namespace Internal {
 
@@ -66,8 +70,8 @@ public:
 
     void setCMakeExecutable(const QString &executable);
 
-    void createXmlFile(QProcess *process,
-                       const QStringList &arguments,
+    void createXmlFile(Utils::QtcProcess *process,
+                       const QString &arguments,
                        const QString &sourceDirectory,
                        const QDir &buildDirectory,
                        const Utils::Environment &env,
diff --git a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.cpp b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.cpp
index b72443ea6c..f1f34bc969 100644
--- a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.cpp
+++ b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.cpp
@@ -141,14 +141,9 @@ QString CMakeRunConfiguration::baseWorkingDirectory() const
     return m_workingDirectory;
 }
 
-QStringList CMakeRunConfiguration::commandLineArguments() const
+QString CMakeRunConfiguration::commandLineArguments() const
 {
-    return environment().expandVariables(baseCommandLineArguments());
-}
-
-QStringList CMakeRunConfiguration::baseCommandLineArguments() const
-{
-    return Utils::Environment::parseCombinedArgString(m_arguments);
+    return m_arguments;
 }
 
 QString CMakeRunConfiguration::title() const
@@ -329,7 +324,7 @@ CMakeRunConfigurationWidget::CMakeRunConfigurationWidget(CMakeRunConfiguration *
     fl->setMargin(0);
     fl->setFieldGrowthPolicy(QFormLayout::ExpandingFieldsGrow);
     QLineEdit *argumentsLineEdit = new QLineEdit();
-    argumentsLineEdit->setText(Utils::Environment::joinArgumentList(cmakeRunConfiguration->baseCommandLineArguments()));
+    argumentsLineEdit->setText(cmakeRunConfiguration->commandLineArguments());
     connect(argumentsLineEdit, SIGNAL(textChanged(QString)),
             this, SLOT(setArguments(QString)));
     fl->addRow(tr("Arguments:"), argumentsLineEdit);
diff --git a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
index 8a84f0dc11..de5971ac07 100644
--- a/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
+++ b/src/plugins/cmakeprojectmanager/cmakerunconfiguration.h
@@ -68,7 +68,7 @@ public:
     QString executable() const;
     RunMode runMode() const;
     QString workingDirectory() const;
-    QStringList commandLineArguments() const;
+    QString commandLineArguments() const;
     Utils::Environment environment() const;
     QWidget *createConfigurationWidget();
 
@@ -104,7 +104,6 @@ protected:
 private:
     void setUserWorkingDirectory(const QString &workingDirectory);
     QString baseWorkingDirectory() const;
-    QStringList baseCommandLineArguments() const;
     void ctor();
 
     enum BaseEnvironmentBase { CleanEnvironmentBase = 0,
diff --git a/src/plugins/cmakeprojectmanager/cmaketarget.cpp b/src/plugins/cmakeprojectmanager/cmaketarget.cpp
index 705eb223bd..c223cd4c7d 100644
--- a/src/plugins/cmakeprojectmanager/cmaketarget.cpp
+++ b/src/plugins/cmakeprojectmanager/cmaketarget.cpp
@@ -209,7 +209,7 @@ CMakeTarget *CMakeTargetFactory::create(ProjectExplorer::Project *parent, const
 
     MakeStep *cleanMakeStep = new MakeStep(cleanSteps);
     cleanSteps->insertStep(0, cleanMakeStep);
-    cleanMakeStep->setAdditionalArguments(QStringList() << "clean");
+    cleanMakeStep->setAdditionalArguments("clean");
     cleanMakeStep->setClean(true);
 
     t->addBuildConfiguration(bc);
diff --git a/src/plugins/cmakeprojectmanager/makestep.cpp b/src/plugins/cmakeprojectmanager/makestep.cpp
index 5689bcdbba..1f1b1e7632 100644
--- a/src/plugins/cmakeprojectmanager/makestep.cpp
+++ b/src/plugins/cmakeprojectmanager/makestep.cpp
@@ -39,6 +39,8 @@
 #include <projectexplorer/projectexplorer.h>
 #include <projectexplorer/gnumakeparser.h>
 
+#include <utils/qtcprocess.h>
+
 #include <QtGui/QFormLayout>
 #include <QtGui/QGroupBox>
 #include <QtGui/QCheckBox>
@@ -78,7 +80,7 @@ MakeStep::MakeStep(BuildStepList *bsl, MakeStep *bs) :
     m_clean(bs->m_clean),
     m_futureInterface(0),
     m_buildTargets(bs->m_buildTargets),
-    m_additionalArguments(bs->m_buildTargets)
+    m_additionalArguments(Utils::QtcProcess::joinArgs(bs->m_buildTargets))
 {
     ctor();
 }
@@ -117,7 +119,7 @@ bool MakeStep::fromMap(const QVariantMap &map)
 {
     m_clean = map.value(QLatin1String(CLEAN_KEY)).toBool();
     m_buildTargets = map.value(QLatin1String(BUILD_TARGETS_KEY)).toStringList();
-    m_additionalArguments = map.value(QLatin1String(ADDITIONAL_ARGUMENTS_KEY)).toStringList();
+    m_additionalArguments = map.value(QLatin1String(ADDITIONAL_ARGUMENTS_KEY)).toString();
 
     return BuildStep::fromMap(map);
 }
@@ -132,8 +134,8 @@ bool MakeStep::init()
 
     setCommand(bc->toolChain()->makeCommand());
 
-    QStringList arguments = m_buildTargets;
-    arguments << additionalArguments();
+    QString arguments = Utils::QtcProcess::joinArgs(m_buildTargets);
+    Utils::QtcProcess::addArgs(&arguments, additionalArguments());
     setArguments(arguments);
     setEnvironment(bc->environment());
     setIgnoreReturnValue(m_clean);
@@ -191,12 +193,12 @@ void MakeStep::setBuildTarget(const QString &buildTarget, bool on)
     m_buildTargets = old;
 }
 
-QStringList MakeStep::additionalArguments() const
+QString MakeStep::additionalArguments() const
 {
     return m_additionalArguments;
 }
 
-void MakeStep::setAdditionalArguments(const QStringList &list)
+void MakeStep::setAdditionalArguments(const QString &list)
 {
     m_additionalArguments = list;
 }
@@ -239,7 +241,7 @@ MakeStepConfigWidget::MakeStepConfigWidget(MakeStep *makeStep)
 
 void MakeStepConfigWidget::additionalArgumentsEdited()
 {
-    m_makeStep->setAdditionalArguments(Utils::Environment::parseCombinedArgString(m_additionalArguments->text()));
+    m_makeStep->setAdditionalArguments(m_additionalArguments->text());
     updateDetails();
 }
 
@@ -266,7 +268,7 @@ void MakeStepConfigWidget::init()
     // and connect again
     connect(m_buildTargetsList, SIGNAL(itemChanged(QListWidgetItem*)), this, SLOT(itemChanged(QListWidgetItem*)));
 
-    m_additionalArguments->setText(Utils::Environment::joinArgumentList(m_makeStep->additionalArguments()));
+    m_additionalArguments->setText(m_makeStep->additionalArguments());
     updateDetails();
 
     CMakeProject *pro = m_makeStep->cmakeBuildConfiguration()->cmakeTarget()->cmakeProject();
@@ -290,13 +292,13 @@ void MakeStepConfigWidget::buildTargetsChanged()
 
 void MakeStepConfigWidget::updateDetails()
 {
-    QStringList arguments = m_makeStep->m_buildTargets;
-    arguments << m_makeStep->additionalArguments();
+    QString arguments = Utils::QtcProcess::joinArgs(m_makeStep->m_buildTargets);
+    Utils::QtcProcess::addArgs(&arguments, m_makeStep->additionalArguments());
 
     CMakeBuildConfiguration *bc = m_makeStep->cmakeBuildConfiguration();
     ProjectExplorer::ToolChain *tc = bc->toolChain();
     if (tc)
-        m_summaryText = tr("<b>Make:</b> %1 %2").arg(tc->makeCommand(), arguments.join(QString(QLatin1Char(' '))));
+        m_summaryText = tr("<b>Make:</b> %1 %2").arg(tc->makeCommand(), arguments);
     else
         m_summaryText = tr("<b>Unknown Toolchain</b>");
     emit updateSummary();
diff --git a/src/plugins/cmakeprojectmanager/makestep.h b/src/plugins/cmakeprojectmanager/makestep.h
index c0ac7bfe97..7da6042d25 100644
--- a/src/plugins/cmakeprojectmanager/makestep.h
+++ b/src/plugins/cmakeprojectmanager/makestep.h
@@ -65,8 +65,8 @@ public:
     virtual bool immutable() const;
     bool buildsBuildTarget(const QString &target) const;
     void setBuildTarget(const QString &target, bool on);
-    QStringList additionalArguments() const;
-    void setAdditionalArguments(const QStringList &list);
+    QString additionalArguments() const;
+    void setAdditionalArguments(const QString &list);
 
     void setClean(bool clean);
 
@@ -88,7 +88,7 @@ private:
     QRegExp m_percentProgress;
     QFutureInterface<bool> *m_futureInterface;
     QStringList m_buildTargets;
-    QStringList m_additionalArguments;
+    QString m_additionalArguments;
 };
 
 class MakeStepConfigWidget :public ProjectExplorer::BuildStepConfigWidget
diff --git a/src/plugins/debugger/cdb/cdbengine.cpp b/src/plugins/debugger/cdb/cdbengine.cpp
index ab09bce6e5..bc0a100c8d 100644
--- a/src/plugins/debugger/cdb/cdbengine.cpp
+++ b/src/plugins/debugger/cdb/cdbengine.cpp
@@ -56,6 +56,7 @@
 
 #include <coreplugin/icore.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/winutils.h>
 #include <utils/consoleprocess.h>
 #include <utils/fancymainwindow.h>
@@ -464,7 +465,17 @@ void CdbEngine::runEngine()
         needWatchTimer = true; // Fetch away module load, etc. even if crashed
         break;
     case StartInternal:
-    case StartExternal:
+    case StartExternal: {
+        Utils::QtcProcess::SplitError perr;
+        QString pargs = Utils::QtcProcess::prepareArgs(sp.processArgs, &perr,
+                                                       &sp.environment, &sp.workingDirectory);
+        if (perr != Utils::QtcProcess::SplitOk) {
+            // perr == BadQuoting is never returned on Windows
+            // FIXME? QTCREATORBUG-2809
+            errorMessage = QApplication::translate("DebuggerEngine", // Same message in GdbEngine
+                    "Debugging complex command lines is currently not supported under Windows");
+            break;
+        }
         if (sp.useTerminal) {
             // Attaching to console processes triggers an initial breakpoint, which we do not want
             m_d->m_ignoreInitialBreakPoint = true;
@@ -472,7 +483,7 @@ void CdbEngine::runEngine()
             m_d->m_consoleStubProc.stop(); // We leave the console open, so recycle it now.
             m_d->m_consoleStubProc.setWorkingDirectory(sp.workingDirectory);
             m_d->m_consoleStubProc.setEnvironment(sp.environment);
-            rc = m_d->m_consoleStubProc.start(sp.executable, sp.processArgs);
+            rc = m_d->m_consoleStubProc.start(sp.executable, pargs);
             if (!rc)
                 errorMessage = tr("The console stub process was unable to start '%1'.").arg(sp.executable);
             // continues in slotConsoleStubStarted()...
@@ -480,11 +491,11 @@ void CdbEngine::runEngine()
             needWatchTimer = true;
             rc = m_d->startDebuggerWithExecutable(sp.workingDirectory,
                                                   sp.executable,
-                                                  sp.processArgs,
-                                                  sp.environment,
+                                                  pargs,
+                                                  sp.environment.toStringList(),
                                                   &errorMessage);
         }
-        break;
+        break; }
     case AttachCore:
         errorMessage = tr("Attaching to core files is not supported.");
         break;
diff --git a/src/plugins/debugger/cdb/coreengine.cpp b/src/plugins/debugger/cdb/coreengine.cpp
index f4b4168bde..0b47cfe6f1 100644
--- a/src/plugins/debugger/cdb/coreengine.cpp
+++ b/src/plugins/debugger/cdb/coreengine.cpp
@@ -465,7 +465,7 @@ void CoreEngine::resetModuleLoadTimer()
 
 bool CoreEngine::startDebuggerWithExecutable(const QString &workingDirectory,
                                              const QString &filename,
-                                             const QStringList &args,
+                                             const QString &args,
                                              const QStringList &envList,
                                              QString *errorMessage)
 {
diff --git a/src/plugins/debugger/cdb/coreengine.h b/src/plugins/debugger/cdb/coreengine.h
index 36d8e9601f..1b3f83c7b8 100644
--- a/src/plugins/debugger/cdb/coreengine.h
+++ b/src/plugins/debugger/cdb/coreengine.h
@@ -86,7 +86,7 @@ public:
     // Start functions
     bool startDebuggerWithExecutable(const QString &workingDirectory,
                                      const QString &filename,
-                                     const QStringList &args,
+                                     const QString &args,
                                      const QStringList &env,
                                      QString *errorMessage);
 
diff --git a/src/plugins/debugger/debuggerengine.cpp b/src/plugins/debugger/debuggerengine.cpp
index d489b92b11..8bc54a88f0 100644
--- a/src/plugins/debugger/debuggerengine.cpp
+++ b/src/plugins/debugger/debuggerengine.cpp
@@ -118,10 +118,9 @@ QDebug operator<<(QDebug d, DebuggerState state)
 QDebug operator<<(QDebug str, const DebuggerStartParameters &sp)
 {
     QDebug nospace = str.nospace();
-    const QString sep = QString(QLatin1Char(','));
     nospace << "executable=" << sp.executable
             << " coreFile=" << sp.coreFile
-            << " processArgs=" << sp.processArgs.join(sep)
+            << " processArgs=" << sp.processArgs
             << " environment=<" << sp.environment.size() << " variables>"
             << " workingDir=" << sp.workingDirectory
             << " attachPID=" << sp.attachPID
@@ -477,8 +476,8 @@ void DebuggerEngine::startDebugger(DebuggerRunControl *runControl)
     d->m_inferiorPid = d->m_startParameters.attachPID > 0
         ? d->m_startParameters.attachPID : 0;
 
-    if (d->m_startParameters.environment.empty())
-        d->m_startParameters.environment = Utils::Environment().toStringList();
+    if (!d->m_startParameters.environment.size())
+        d->m_startParameters.environment = Utils::Environment();
 
     if (d->m_startParameters.breakAtMain)
         breakByFunctionMain();
diff --git a/src/plugins/debugger/debuggerengine.h b/src/plugins/debugger/debuggerengine.h
index cb439dd387..4ebf9f731a 100644
--- a/src/plugins/debugger/debuggerengine.h
+++ b/src/plugins/debugger/debuggerengine.h
@@ -37,6 +37,8 @@
 
 #include <coreplugin/ssh/sshconnection.h> 
 
+#include <utils/environment.h>
+
 #include <QtCore/QObject>
 #include <QtCore/QStringList>
 
@@ -70,8 +72,8 @@ public:
     QString displayName;
     QString coreFile;
     bool isSnapshot; // set if created internally
-    QStringList processArgs;
-    QStringList environment;
+    QString processArgs;
+    Utils::Environment environment;
     QString workingDirectory;
     qint64 attachPID;
     bool useTerminal;
diff --git a/src/plugins/debugger/debuggerplugin.cpp b/src/plugins/debugger/debuggerplugin.cpp
index 8dc968c065..bd89729453 100644
--- a/src/plugins/debugger/debuggerplugin.cpp
+++ b/src/plugins/debugger/debuggerplugin.cpp
@@ -2047,10 +2047,9 @@ void DebuggerPluginPrivate::startExternalApplication()
     sp.workingDirectory = dlg.workingDirectory();
     sp.breakAtMain = dlg.breakAtMain();
     if (!dlg.executableArguments().isEmpty())
-        sp.processArgs = dlg.executableArguments().split(QLatin1Char(' '));
+        sp.processArgs = dlg.executableArguments();
     // Fixme: 1 of 3 testing hacks.
-    if (!sp.processArgs.isEmpty()
-        && (sp.processArgs.front() == _("@tcf@") || sp.processArgs.front() == _("@sym@")))
+    if (sp.processArgs.startsWith(__("@tcf@ ")) || sp.processArgs.startsWith(__("@sym@ ")))
         sp.toolChainType = ProjectExplorer::ToolChain_RVCT_ARMV5;
 
 
diff --git a/src/plugins/debugger/debuggerrunner.cpp b/src/plugins/debugger/debuggerrunner.cpp
index 5362ecc261..2c1a6240ae 100644
--- a/src/plugins/debugger/debuggerrunner.cpp
+++ b/src/plugins/debugger/debuggerrunner.cpp
@@ -171,7 +171,7 @@ static DebuggerStartParameters localStartParameters(RunConfiguration *runConfigu
     QTC_ASSERT(rc, return sp);
 
     sp.startMode = StartInternal;
-    sp.environment = rc->environment().toStringList();
+    sp.environment = rc->environment();
     sp.workingDirectory = rc->workingDirectory();
     sp.executable = rc->executable();
     sp.processArgs = rc->commandLineArguments();
@@ -429,7 +429,7 @@ void DebuggerRunControl::createEngine(const DebuggerStartParameters &startParams
     }
 
     // Fixme: 1 of 3 testing hacks.
-    if (sp.processArgs.size() >= 5 && sp.processArgs.at(0) == _("@tcf@"))
+    if (sp.processArgs.startsWith(__("@tcf@ ")))
         engineType = GdbEngineType;
 
     if (sp.processArgs.contains( _("@lldb@")))
@@ -525,7 +525,7 @@ QString DebuggerRunControl::displayName() const
 
 void DebuggerRunControl::setCustomEnvironment(Utils::Environment env)
 {
-    d->m_engine->startParameters().environment = env.toStringList();
+    d->m_engine->startParameters().environment = env;
 }
 
 bool DebuggerRunControl::checkDebugConfiguration(int toolChain,
diff --git a/src/plugins/debugger/gdb/abstractgdbadapter.cpp b/src/plugins/debugger/gdb/abstractgdbadapter.cpp
index b0f80d39f8..2454dde0ed 100644
--- a/src/plugins/debugger/gdb/abstractgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/abstractgdbadapter.cpp
@@ -32,6 +32,9 @@
 #include "abstractgdbprocess.h"
 
 #include <utils/qtcassert.h>
+#ifdef Q_OS_WIN
+#include <utils/qtcprocess.h>
+#endif
 
 #include <QtCore/QProcess>
 
@@ -74,6 +77,24 @@ bool AbstractGdbAdapter::isTrkAdapter() const
     return false;
 }
 
+#ifdef Q_OS_WIN
+bool AbstractGdbAdapter::prepareWinCommand()
+{
+    Utils::QtcProcess::SplitError perr;
+    startParameters().processArgs = Utils::QtcProcess::prepareArgs(
+                startParameters().processArgs, &perr,
+                &startParameters().environment, &startParameters().workingDirectory);
+    if (perr != Utils::QtcProcess::SplitOk) {
+        // perr == BadQuoting is never returned on Windows
+        // FIXME? QTCREATORBUG-2809
+        m_engine->handleAdapterStartFailed(QApplication::translate("DebuggerEngine", // Same message in CdbEngine
+            "Debugging complex command lines is currently not supported under Windows"), QString());
+        return false;
+    }
+    return true;
+}
+#endif
+
 QString AbstractGdbAdapter::msgGdbStopFailed(const QString &why)
 {
     return tr("The Gdb process could not be stopped:\n%1").arg(why);
diff --git a/src/plugins/debugger/gdb/abstractgdbadapter.h b/src/plugins/debugger/gdb/abstractgdbadapter.h
index 82e8676a8a..033f51cac3 100644
--- a/src/plugins/debugger/gdb/abstractgdbadapter.h
+++ b/src/plugins/debugger/gdb/abstractgdbadapter.h
@@ -95,6 +95,9 @@ protected:
     const DebuggerStartParameters &startParameters() const;
     DebuggerStartParameters &startParameters();
     void showMessage(const QString &msg, int channel = LogDebug, int timeout = 1);
+#ifdef Q_OS_WIN
+    bool prepareWinCommand();
+#endif
 
     GdbEngine * const m_engine;
 };
diff --git a/src/plugins/debugger/gdb/abstractplaingdbadapter.cpp b/src/plugins/debugger/gdb/abstractplaingdbadapter.cpp
index e4e7ea16a9..6fdcf482b7 100644
--- a/src/plugins/debugger/gdb/abstractplaingdbadapter.cpp
+++ b/src/plugins/debugger/gdb/abstractplaingdbadapter.cpp
@@ -53,7 +53,7 @@ void AbstractPlainGdbAdapter::setupInferior()
 {
     QTC_ASSERT(state() == InferiorSetupRequested, qDebug() << state());
     if (!startParameters().processArgs.isEmpty()) {
-        QString args = startParameters().processArgs.join(_(" "));
+        QString args = startParameters().processArgs;
         m_engine->postCommand("-exec-arguments " + toLocalEncoding(args));
     }
     m_engine->postCommand("-file-exec-and-symbols \"" + execFilePath() + '"',
diff --git a/src/plugins/debugger/gdb/gdbengine.cpp b/src/plugins/debugger/gdb/gdbengine.cpp
index 2b71b9b2e6..25935c654b 100644
--- a/src/plugins/debugger/gdb/gdbengine.cpp
+++ b/src/plugins/debugger/gdb/gdbengine.cpp
@@ -1708,7 +1708,7 @@ AbstractGdbAdapter *GdbEngine::createAdapter()
         case ProjectExplorer::ToolChain_RVCT_ARMV5_GNUPOC:
         case ProjectExplorer::ToolChain_GCCE_GNUPOC:
             // fixme: 1 of 3 testing hacks
-            if (sp.processArgs.size() >= 5 && sp.processArgs.at(0) == _("@tcf@"))
+            if (sp.processArgs.startsWith(__("@tcf@ ")))
                 return new TcfTrkGdbAdapter(this);
             return new TrkGdbAdapter(this);
         default:
diff --git a/src/plugins/debugger/gdb/localplaingdbadapter.cpp b/src/plugins/debugger/gdb/localplaingdbadapter.cpp
index 89a8d549ab..a33a177126 100644
--- a/src/plugins/debugger/gdb/localplaingdbadapter.cpp
+++ b/src/plugins/debugger/gdb/localplaingdbadapter.cpp
@@ -72,6 +72,11 @@ void LocalPlainGdbAdapter::startAdapter()
     QTC_ASSERT(state() == EngineSetupRequested, qDebug() << state());
     showMessage(_("TRYING TO START ADAPTER"));
 
+#ifdef Q_OS_WIN
+    if (!prepareWinCommand())
+        return;
+#endif
+
     QStringList gdbArgs;
 
     if (!m_outputCollector.listen()) {
@@ -83,8 +88,8 @@ void LocalPlainGdbAdapter::startAdapter()
 
     if (!startParameters().workingDirectory.isEmpty())
         m_gdbProc.setWorkingDirectory(startParameters().workingDirectory);
-    if (!startParameters().environment.isEmpty())
-        m_gdbProc.setEnvironment(startParameters().environment);
+    if (startParameters().environment.size())
+        m_gdbProc.setEnvironment(startParameters().environment.toStringList());
 
     if (!m_engine->startGdb(gdbArgs)) {
         m_outputCollector.shutdown();
diff --git a/src/plugins/debugger/gdb/remotegdbprocess.cpp b/src/plugins/debugger/gdb/remotegdbprocess.cpp
index 4ad44945df..c88c0ba2d3 100644
--- a/src/plugins/debugger/gdb/remotegdbprocess.cpp
+++ b/src/plugins/debugger/gdb/remotegdbprocess.cpp
@@ -32,6 +32,7 @@
 #include "remoteplaingdbadapter.h"
 
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QFileInfo>
 
@@ -143,11 +144,11 @@ void RemoteGdbProcess::handleAppOutputReaderStarted()
 
     connect(m_appOutputReader.data(), SIGNAL(outputAvailable(QByteArray)),
         this, SLOT(handleAppOutput(QByteArray)));
-    QByteArray cmdLine = "DISPLAY=:0.0 " + m_command.toUtf8() + ' '
-        + m_cmdArgs.join(QLatin1String(" ")).toUtf8()
+    QByteArray cmdLine = "DISPLAY=:0.0 " + Utils::QtcProcess::quoteArgUnix(m_command).toUtf8() + ' '
+        + Utils::QtcProcess::joinArgsUnix(m_cmdArgs).toUtf8()
         + " -tty=" + m_appOutputFileName;
     if (!m_wd.isEmpty())
-        cmdLine.prepend("cd " + m_wd.toUtf8() + " && ");
+        cmdLine.prepend("cd " + Utils::QtcProcess::quoteArgUnix(m_wd).toUtf8() + " && ");
     m_gdbProc = m_conn->createRemoteProcess(cmdLine);
     connect(m_gdbProc.data(), SIGNAL(started()), this,
         SLOT(handleGdbStarted()));
diff --git a/src/plugins/debugger/gdb/remotegdbserveradapter.cpp b/src/plugins/debugger/gdb/remotegdbserveradapter.cpp
index 006dbb2ab7..629c744372 100644
--- a/src/plugins/debugger/gdb/remotegdbserveradapter.cpp
+++ b/src/plugins/debugger/gdb/remotegdbserveradapter.cpp
@@ -176,7 +176,7 @@ void RemoteGdbServerAdapter::setupInferior()
     const QByteArray gnuTarget = startParameters().gnuTarget.toLatin1();
     const QByteArray solibPath =
          QFileInfo(startParameters().dumperLibrary).path().toLocal8Bit();
-    const QString args = startParameters().processArgs.join(_(" "));
+    const QString args = startParameters().processArgs;
 
     if (!remoteArch.isEmpty())
         m_engine->postCommand("set architecture " + remoteArch);
diff --git a/src/plugins/debugger/gdb/remoteplaingdbadapter.cpp b/src/plugins/debugger/gdb/remoteplaingdbadapter.cpp
index 8ad74bdac8..559bb0bd80 100644
--- a/src/plugins/debugger/gdb/remoteplaingdbadapter.cpp
+++ b/src/plugins/debugger/gdb/remoteplaingdbadapter.cpp
@@ -109,8 +109,8 @@ void RemotePlainGdbAdapter::handleSetupDone(int qmlPort)
         startParameters().qmlServerPort = qmlPort;
     if (!startParameters().workingDirectory.isEmpty())
         m_gdbProc.setWorkingDirectory(startParameters().workingDirectory);
-    if (!startParameters().environment.isEmpty())
-        m_gdbProc.setEnvironment(startParameters().environment);
+    if (startParameters().environment.size())
+        m_gdbProc.setEnvironment(startParameters().environment.toStringList());
     m_gdbProc.realStart(m_engine->startParameters().debuggerCommand,
         QStringList() << QLatin1String("-i") << QLatin1String("mi"),
         m_engine->startParameters().executable);
diff --git a/src/plugins/debugger/gdb/tcftrkgdbadapter.cpp b/src/plugins/debugger/gdb/tcftrkgdbadapter.cpp
index cf2b8c3007..890b79a13f 100644
--- a/src/plugins/debugger/gdb/tcftrkgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/tcftrkgdbadapter.cpp
@@ -44,6 +44,7 @@
 
 #include <utils/qtcassert.h>
 #include <utils/savedaction.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QTimer>
 #include <QtCore/QDir>
@@ -971,7 +972,7 @@ void TcfTrkGdbAdapter::startAdapter()
     // Retrieve parameters
     const DebuggerStartParameters &parameters = startParameters();
     m_remoteExecutable = parameters.executable;
-    m_remoteArguments = parameters.processArgs;
+    m_remoteArguments = Utils::QtcProcess::splitArgs(parameters.processArgs);
     m_symbolFile = parameters.symbolFileName;
 
     QPair<QString, unsigned short> tcfTrkAddress;
@@ -983,15 +984,15 @@ void TcfTrkGdbAdapter::startAdapter()
     if (debug)
         qDebug() << parameters.processArgs;
     // Fixme: 1 of 3 testing hacks.
-    if (parameters.processArgs.size() < 5 || parameters.processArgs.at(0) != _("@tcf@")) {
+    if (m_remoteArguments.size() < 5 || m_remoteArguments.at(0) != __("@tcf@")) {
         m_engine->handleAdapterStartFailed(_("Parameter error"), QString());
         return;
     }
 
-    m_remoteExecutable = parameters.processArgs.at(1);
-    m_uid = parameters.processArgs.at(2).toUInt(0, 16);
-    m_symbolFile = parameters.processArgs.at(3);
-    tcfTrkAddress = splitIpAddressSpec(parameters.processArgs.at(4), 1534);
+    m_remoteExecutable = m_remoteArguments.at(1);
+    m_uid = m_remoteArguments.at(2).toUInt(0, 16);
+    m_symbolFile = m_remoteArguments.at(3);
+    tcfTrkAddress = splitIpAddressSpec(m_remoteArguments.at(4), 1534);
     m_remoteArguments.clear();
 
     // Unixish gdbs accept only forward slashes
diff --git a/src/plugins/debugger/gdb/termgdbadapter.cpp b/src/plugins/debugger/gdb/termgdbadapter.cpp
index 1f9826d20d..64b1b68421 100644
--- a/src/plugins/debugger/gdb/termgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/termgdbadapter.cpp
@@ -96,10 +96,14 @@ void TermGdbAdapter::startAdapter()
 //    m_stubProc.stop();
 //    m_stubProc.blockSignals(false);
 
+#ifdef Q_OS_WIN
+    if (!prepareWinCommand())
+        return;
+#endif
+
     m_stubProc.setWorkingDirectory(startParameters().workingDirectory);
     // Set environment + dumper preload.
-    QStringList environment = startParameters().environment;
-    m_stubProc.setEnvironment(environment);
+    m_stubProc.setEnvironment(startParameters().environment);
     // FIXME: Starting the stub implies starting the inferior. This is
     // fairly unclean as far as the state machine and error reporting go.
     if (!m_stubProc.start(startParameters().executable,
diff --git a/src/plugins/debugger/gdb/trkgdbadapter.cpp b/src/plugins/debugger/gdb/trkgdbadapter.cpp
index c5790f26f6..8b235edfae 100644
--- a/src/plugins/debugger/gdb/trkgdbadapter.cpp
+++ b/src/plugins/debugger/gdb/trkgdbadapter.cpp
@@ -46,6 +46,7 @@
 #endif
 
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/savedaction.h>
 
 #include <QtCore/QTimer>
@@ -1551,10 +1552,11 @@ void TrkGdbAdapter::startAdapter()
     m_symbolFile = parameters.symbolFileName;
     QString remoteChannel = parameters.remoteChannel;
     // FIXME: testing hack, remove!
-    if (parameters.processArgs.size() >= 4 && parameters.processArgs.at(0) == _("@sym@")) {
-        remoteChannel = parameters.processArgs.at(1);
-        m_remoteExecutable = parameters.processArgs.at(2);
-        m_symbolFile = parameters.processArgs.at(3);
+    if (m_remoteArguments.startsWith(__("@sym@ "))) {
+        QStringList pa = Utils::QtcProcess::splitArgs(m_remoteArguments);
+        remoteChannel = pa.at(1);
+        m_remoteExecutable = pa.at(2);
+        m_symbolFile = pa.at(3);
         m_remoteArguments.clear();
     }
     // Unixish gdbs accept only forward slashes
diff --git a/src/plugins/debugger/gdb/trkgdbadapter.h b/src/plugins/debugger/gdb/trkgdbadapter.h
index 93fadcccec..7c7905fbde 100644
--- a/src/plugins/debugger/gdb/trkgdbadapter.h
+++ b/src/plugins/debugger/gdb/trkgdbadapter.h
@@ -224,7 +224,7 @@ private:
     trk::Session m_session; // global-ish data (process id, target information)
     Symbian::Snapshot m_snapshot; // local-ish data (memory and registers)
     QString m_remoteExecutable;
-    QStringList m_remoteArguments;
+    QString m_remoteArguments;
     QString m_symbolFile;
     int m_verbose;
     bool m_bufferedMemoryRead;
diff --git a/src/plugins/debugger/lldb/ipcenginehost.cpp b/src/plugins/debugger/lldb/ipcenginehost.cpp
index a654aa9bf5..b8913655a1 100644
--- a/src/plugins/debugger/lldb/ipcenginehost.cpp
+++ b/src/plugins/debugger/lldb/ipcenginehost.cpp
@@ -101,7 +101,7 @@ void IPCEngineHost::setupInferior()
         SET_NATIVE_BYTE_ORDER(s);
         s << QFileInfo(startParameters().executable).absoluteFilePath();
         s << startParameters().processArgs;
-        s << startParameters().environment;
+        s << startParameters().environment.toStringList();
     }
     rpcCall(SetupInferior, p);
 }
diff --git a/src/plugins/debugger/qml/qmlengine.cpp b/src/plugins/debugger/qml/qmlengine.cpp
index f75433b5cd..006a15e5e4 100644
--- a/src/plugins/debugger/qml/qmlengine.cpp
+++ b/src/plugins/debugger/qml/qmlengine.cpp
@@ -791,13 +791,7 @@ bool QmlEngine::isShadowBuildProject() const
 
 QString QmlEngine::qmlImportPath() const
 {
-    const QString qmlImportPathPrefix("QML_IMPORT_PATH=");
-    QStringList env = startParameters().environment;
-    foreach (const QString &envStr, env) {
-        if (envStr.startsWith(qmlImportPathPrefix))
-            return envStr.mid(qmlImportPathPrefix.length());
-    }
-    return QString();
+    return startParameters().environment.value("QML_IMPORT_PATH");
 }
 
 QString QmlEngine::toShadowBuildFilename(const QString &filename) const
diff --git a/src/plugins/genericprojectmanager/genericmakestep.cpp b/src/plugins/genericprojectmanager/genericmakestep.cpp
index 5776f2593e..f633144f4b 100644
--- a/src/plugins/genericprojectmanager/genericmakestep.cpp
+++ b/src/plugins/genericprojectmanager/genericmakestep.cpp
@@ -42,6 +42,7 @@
 #include <coreplugin/variablemanager.h>
 #include <utils/stringutils.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtGui/QFormLayout>
 #include <QtGui/QGroupBox>
@@ -132,26 +133,18 @@ QVariantMap GenericMakeStep::toMap() const
 bool GenericMakeStep::fromMap(const QVariantMap &map)
 {
     m_buildTargets = map.value(QLatin1String(BUILD_TARGETS_KEY)).toStringList();
-    m_makeArguments = map.value(QLatin1String(MAKE_ARGUMENTS_KEY)).toStringList();
+    m_makeArguments = map.value(QLatin1String(MAKE_ARGUMENTS_KEY)).toString();
     m_makeCommand = map.value(QLatin1String(MAKE_COMMAND_KEY)).toString();
 
     return BuildStep::fromMap(map);
 }
 
-QStringList GenericMakeStep::replacedArguments() const
+QString GenericMakeStep::replacedArguments() const
 {
-    Utils::AbstractMacroExpander *mx = Core::VariableManager::instance()->macroExpander();
-    const QStringList targets = m_buildTargets;
-    QStringList arguments = m_makeArguments;
-    QStringList replacedArguments;
-    foreach (QString arg, arguments) {
-        Utils::expandMacros(&arg, mx);
-        replacedArguments << arg;
-    }
-    foreach (QString arg, targets) {
-        Utils::expandMacros(&arg, mx);
-        replacedArguments << arg;
-    }
+    QString replacedArguments = m_makeArguments;
+    Utils::QtcProcess::addArgs(&replacedArguments, m_buildTargets);
+    Utils::QtcProcess::expandMacros(&replacedArguments,
+                                    Core::VariableManager::instance()->macroExpander());
     return replacedArguments;
 }
 
@@ -245,11 +238,8 @@ void GenericMakeStepConfigWidget::init()
 {
     updateMakeOverrrideLabel();
 
-    QString makeCommand = m_makeStep->m_makeCommand;
-    m_ui->makeLineEdit->setText(makeCommand);
-
-    const QStringList &makeArguments = m_makeStep->m_makeArguments;
-    m_ui->makeArgumentsLineEdit->setText(Utils::Environment::joinArgumentList(makeArguments));
+    m_ui->makeLineEdit->setText(m_makeStep->m_makeCommand);
+    m_ui->makeArgumentsLineEdit->setText(m_makeStep->m_makeArguments);
 
     // Disconnect to make the changes to the items
     disconnect(m_ui->targetsList, SIGNAL(itemChanged(QListWidgetItem*)), this, SLOT(itemChanged(QListWidgetItem*)));
@@ -268,8 +258,7 @@ void GenericMakeStepConfigWidget::init()
 void GenericMakeStepConfigWidget::updateDetails()
 {
     m_summaryText = tr("<b>Make:</b> %1 %2")
-                    .arg(m_makeStep->makeCommand(),
-                         Utils::Environment::joinArgumentList(m_makeStep->replacedArguments()));
+                    .arg(m_makeStep->makeCommand(), m_makeStep->replacedArguments());
     emit updateSummary();
 }
 
@@ -292,8 +281,7 @@ void GenericMakeStepConfigWidget::makeLineEditTextEdited()
 
 void GenericMakeStepConfigWidget::makeArgumentsLineEditTextEdited()
 {
-    m_makeStep->m_makeArguments =
-            Utils::Environment::parseCombinedArgString(m_ui->makeArgumentsLineEdit->text());
+    m_makeStep->m_makeArguments = m_ui->makeArgumentsLineEdit->text();
     updateDetails();
 }
 
diff --git a/src/plugins/genericprojectmanager/genericmakestep.h b/src/plugins/genericprojectmanager/genericmakestep.h
index 1326e53005..27830b69a0 100644
--- a/src/plugins/genericprojectmanager/genericmakestep.h
+++ b/src/plugins/genericprojectmanager/genericmakestep.h
@@ -67,7 +67,7 @@ public:
     virtual bool immutable() const;
     bool buildsTarget(const QString &target) const;
     void setBuildTarget(const QString &target, bool on);
-    QStringList replacedArguments() const;
+    QString replacedArguments() const;
     QString makeCommand() const;
 
     QVariantMap toMap() const;
@@ -81,7 +81,7 @@ private:
     void ctor();
 
     QStringList m_buildTargets;
-    QStringList m_makeArguments;
+    QString m_makeArguments;
     QString m_makeCommand;
 };
 
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index fad4e9391e..3bf8ccdfac 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -49,6 +49,7 @@
 
 #include <texteditor/itexteditor.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/synchronousprocess.h>
 #include <utils/environment.h>
 #include <vcsbase/vcsbaseeditor.h>
@@ -1352,7 +1353,7 @@ bool GitClient::tryLauchingGitK(const QProcessEnvironment &env,
 #endif
     VCSBase::VCSBaseOutputWindow *outwin = VCSBase::VCSBaseOutputWindow::instance();
     if (!m_settings.gitkOptions.isEmpty())
-        arguments.append(m_settings.gitkOptions.split(QLatin1Char(' ')));
+        arguments.append(Utils::QtcProcess::splitArgs(m_settings.gitkOptions));
     outwin->appendCommand(workingDirectory, binary, arguments);
     // This should always use QProcess::startDetached (as not to kill
     // the child), but that does not have an environment parameter.
diff --git a/src/plugins/projectexplorer/abstractprocessstep.cpp b/src/plugins/projectexplorer/abstractprocessstep.cpp
index 7234b0479b..0576acc3ca 100644
--- a/src/plugins/projectexplorer/abstractprocessstep.cpp
+++ b/src/plugins/projectexplorer/abstractprocessstep.cpp
@@ -35,6 +35,7 @@
 #include "target.h"
 
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QEventLoop>
 #include <QtCore/QTimer>
@@ -113,12 +114,12 @@ void AbstractProcessStep::setWorkingDirectory(const QString &workingDirectory)
     m_workingDirectory = workingDirectory;
 }
 
-void AbstractProcessStep::setArguments(const QStringList &arguments)
+void AbstractProcessStep::setArguments(const QString &arguments)
 {
     m_arguments = arguments;
 }
 
-QStringList AbstractProcessStep::arguments() const
+QString AbstractProcessStep::arguments() const
 {
     return m_arguments;
 }
@@ -154,9 +155,9 @@ void AbstractProcessStep::run(QFutureInterface<bool> &fi)
     if (!wd.exists())
         wd.mkpath(wd.absolutePath());
 
-    m_process = new QProcess();
+    m_process = new Utils::QtcProcess();
     m_process->setWorkingDirectory(wd.absolutePath());
-    m_process->setEnvironment(m_environment.toStringList());
+    m_process->setEnvironment(m_environment);
 
     connect(m_process, SIGNAL(readyReadStandardOutput()),
             this, SLOT(processReadyReadStdOutput()),
@@ -169,7 +170,8 @@ void AbstractProcessStep::run(QFutureInterface<bool> &fi)
             this, SLOT(slotProcessFinished(int, QProcess::ExitStatus)),
             Qt::DirectConnection);
 
-    m_process->start(expandedCommand(), m_environment.expandVariables(m_arguments));
+    m_process->setCommand(expandedCommand(), m_arguments);
+    m_process->start();
     if (!m_process->waitForStarted()) {
         processStartupFailed();
         delete m_process;
@@ -210,8 +212,7 @@ void AbstractProcessStep::run(QFutureInterface<bool> &fi)
 void AbstractProcessStep::processStarted()
 {
     emit addOutput(tr("Starting: \"%1\" %2\n")
-                   .arg(QDir::toNativeSeparators(expandedCommand()),
-                        m_environment.expandVariables(m_arguments).join(QChar(' '))),
+                   .arg(QDir::toNativeSeparators(expandedCommand()), expandedArguments()),
                    BuildStep::MessageOutput);
 }
 
@@ -232,9 +233,8 @@ void AbstractProcessStep::processFinished(int exitCode, QProcess::ExitStatus sta
 
 void AbstractProcessStep::processStartupFailed()
 {
-    emit addOutput(tr("Could not start process \"%1\" %2").
-                   arg(QDir::toNativeSeparators(expandedCommand()),
-                       m_environment.expandVariables(m_arguments).join(QChar(' '))),
+    emit addOutput(tr("Could not start process \"%1\" %2")
+                   .arg(QDir::toNativeSeparators(expandedCommand()), expandedArguments()),
                    BuildStep::ErrorMessageOutput);
 }
 
@@ -359,3 +359,21 @@ QString AbstractProcessStep::expandedCommand() const
         command = m_command;
     return command;
 }
+
+QString AbstractProcessStep::expandedArguments() const
+{
+#ifdef Q_OS_WIN
+    QString args;
+#else
+    QStringList args;
+#endif
+    Utils::QtcProcess::SplitError err;
+    args = Utils::QtcProcess::prepareArgs(m_arguments, &err, &m_environment);
+    if (err != Utils::QtcProcess::SplitOk)
+        return m_arguments; // Sorry, too complex - just fall back.
+#ifdef Q_OS_WIN
+    return args;
+#else
+    return Utils::QtcProcess::joinArgs(args);
+#endif
+}
diff --git a/src/plugins/projectexplorer/abstractprocessstep.h b/src/plugins/projectexplorer/abstractprocessstep.h
index 78e4723fa4..bf079dae4b 100644
--- a/src/plugins/projectexplorer/abstractprocessstep.h
+++ b/src/plugins/projectexplorer/abstractprocessstep.h
@@ -34,8 +34,9 @@
 
 #include <utils/environment.h>
 
+#include <utils/qtcprocess.h>
+
 #include <QtCore/QString>
-#include <QtCore/QProcess>
 
 QT_BEGIN_NAMESPACE
 class QEventLoop;
@@ -93,8 +94,8 @@ public:
 
     /// sets the command line arguments used by the process for a \p buildConfiguration
     /// should be called from init()
-    void setArguments(const QStringList &arguments);
-    QStringList arguments() const;
+    void setArguments(const QString &arguments);
+    QString arguments() const;
 
     /// enables or disables a BuildStep
     /// Disabled BuildSteps immediately return true from their run method
@@ -125,6 +126,8 @@ protected:
 
     /// Get the fully expanded command name to run:
     QString expandedCommand() const;
+    /// Get the fully expanded command line args. This is for display purposes only!
+    QString expandedArguments() const;
 
     /// Called after the process is started
     /// the default implementation adds a process started message to the output message
@@ -161,10 +164,10 @@ private:
     QFutureInterface<bool> *m_futureInterface;
     QString m_workingDirectory;
     QString m_command;
-    QStringList m_arguments;
+    QString m_arguments;
     bool m_enabled;
     bool m_ignoreReturnValue;
-    QProcess *m_process;
+    Utils::QtcProcess *m_process;
     QEventLoop *m_eventLoop;
     Utils::Environment m_environment;
     ProjectExplorer::IOutputParser *m_outputParserChain;
diff --git a/src/plugins/projectexplorer/applicationlauncher.h b/src/plugins/projectexplorer/applicationlauncher.h
index a35f654eaa..4f7a2c9bdc 100644
--- a/src/plugins/projectexplorer/applicationlauncher.h
+++ b/src/plugins/projectexplorer/applicationlauncher.h
@@ -32,12 +32,10 @@
 
 #include "projectexplorer_export.h"
 
-#include <QtCore/QObject>
-#include <QtCore/QStringList>
 #include <QtCore/QProcess>
 
 namespace Utils {
-class ConsoleProcess;
+class Environment;
 }
 
 namespace ProjectExplorer {
@@ -57,10 +55,10 @@ public:
     ~ApplicationLauncher();
 
     void setWorkingDirectory(const QString &dir);
-    void setEnvironment(const QStringList &env);
+    void setEnvironment(const Utils::Environment &env);
 
     void start(Mode mode, const QString &program,
-               const QStringList &args = QStringList());
+               const QString &args = QString());
     void stop();
     bool isRunning() const;
     qint64 applicationPID() const;
diff --git a/src/plugins/projectexplorer/applicationlauncher_win.cpp b/src/plugins/projectexplorer/applicationlauncher_win.cpp
index eb61352dcc..e5df2b1b67 100644
--- a/src/plugins/projectexplorer/applicationlauncher_win.cpp
+++ b/src/plugins/projectexplorer/applicationlauncher_win.cpp
@@ -69,13 +69,13 @@ void ApplicationLauncher::setWorkingDirectory(const QString &dir)
     d->m_consoleProcess.setWorkingDirectory(dir);
 }
 
-void ApplicationLauncher::setEnvironment(const QStringList &env)
+void ApplicationLauncher::setEnvironment(const Utils::Environment &env)
 {
     d->m_winGuiProcess.setEnvironment(env);
     d->m_consoleProcess.setEnvironment(env);
 }
 
-void ApplicationLauncher::start(Mode mode, const QString &program, const QStringList &args)
+void ApplicationLauncher::start(Mode mode, const QString &program, const QString &args)
 {
     d->m_currentMode = mode;
     if (mode == Gui) {
diff --git a/src/plugins/projectexplorer/applicationlauncher_x11.cpp b/src/plugins/projectexplorer/applicationlauncher_x11.cpp
index d058c96f95..63963b3878 100644
--- a/src/plugins/projectexplorer/applicationlauncher_x11.cpp
+++ b/src/plugins/projectexplorer/applicationlauncher_x11.cpp
@@ -32,6 +32,8 @@
 
 #include <coreplugin/icore.h>
 
+#include <utils/qtcprocess.h>
+
 #include <QtCore/QTimer>
 #include <QtCore/QTextCodec>
 
@@ -40,7 +42,7 @@ namespace ProjectExplorer {
 struct ApplicationLauncherPrivate {
     ApplicationLauncherPrivate();
 
-    QProcess m_guiProcess;
+    Utils::QtcProcess m_guiProcess;
     Utils::ConsoleProcess m_consoleProcess;
     ApplicationLauncher::Mode m_currentMode;
 
@@ -87,17 +89,18 @@ void ApplicationLauncher::setWorkingDirectory(const QString &dir)
     d->m_consoleProcess.setWorkingDirectory(dir);
 }
 
-void ApplicationLauncher::setEnvironment(const QStringList &env)
+void ApplicationLauncher::setEnvironment(const Utils::Environment &env)
 {
     d->m_guiProcess.setEnvironment(env);
     d->m_consoleProcess.setEnvironment(env);
 }
 
-void ApplicationLauncher::start(Mode mode, const QString &program, const QStringList &args)
+void ApplicationLauncher::start(Mode mode, const QString &program, const QString &args)
 {
     d->m_currentMode = mode;
     if (mode == Gui) {
-        d->m_guiProcess.start(program, args);
+        d->m_guiProcess.setCommand(program, args);
+        d->m_guiProcess.start();
     } else {
         d->m_consoleProcess.start(program, args);
     }
diff --git a/src/plugins/projectexplorer/applicationrunconfiguration.cpp b/src/plugins/projectexplorer/applicationrunconfiguration.cpp
index c1963bc065..7ad4c8fc57 100644
--- a/src/plugins/projectexplorer/applicationrunconfiguration.cpp
+++ b/src/plugins/projectexplorer/applicationrunconfiguration.cpp
@@ -48,4 +48,3 @@ LocalApplicationRunConfiguration::~LocalApplicationRunConfiguration()
 }
 
 } // namespace ProjectExplorer
-
diff --git a/src/plugins/projectexplorer/applicationrunconfiguration.h b/src/plugins/projectexplorer/applicationrunconfiguration.h
index 49092e260a..c0e2323131 100644
--- a/src/plugins/projectexplorer/applicationrunconfiguration.h
+++ b/src/plugins/projectexplorer/applicationrunconfiguration.h
@@ -54,7 +54,7 @@ public:
     virtual QString executable() const = 0;
     virtual RunMode runMode() const = 0;
     virtual QString workingDirectory() const = 0;
-    virtual QStringList commandLineArguments() const = 0;
+    virtual QString commandLineArguments() const = 0;
     virtual Utils::Environment environment() const = 0;
     virtual QString dumperLibrary() const = 0;
     virtual QStringList dumperLibraryLocations() const = 0;
diff --git a/src/plugins/projectexplorer/customexecutableconfigurationwidget.cpp b/src/plugins/projectexplorer/customexecutableconfigurationwidget.cpp
index 2d1b3399a8..d4266937ef 100644
--- a/src/plugins/projectexplorer/customexecutableconfigurationwidget.cpp
+++ b/src/plugins/projectexplorer/customexecutableconfigurationwidget.cpp
@@ -231,7 +231,7 @@ void CustomExecutableConfigurationWidget::executableEdited()
 void CustomExecutableConfigurationWidget::argumentsEdited(const QString &arguments)
 {
     m_ignoreChange = true;
-    m_runConfiguration->setBaseCommandLineArguments(arguments);
+    m_runConfiguration->setCommandLineArguments(arguments);
     m_ignoreChange = false;
 }
 void CustomExecutableConfigurationWidget::workingDirectoryEdited()
@@ -256,7 +256,7 @@ void CustomExecutableConfigurationWidget::changed()
         return;
 
     m_executableChooser->setPath(m_runConfiguration->rawExecutable());
-    m_commandLineArgumentsLineEdit->setText(Utils::Environment::joinArgumentList(m_runConfiguration->baseCommandLineArguments()));
+    m_commandLineArgumentsLineEdit->setText(m_runConfiguration->commandLineArguments());
     m_workingDirectory->setPath(m_runConfiguration->baseWorkingDirectory());
     m_useTerminalCheck->setChecked(m_runConfiguration->runMode() == LocalApplicationRunConfiguration::Console);
 }
diff --git a/src/plugins/projectexplorer/customexecutablerunconfiguration.cpp b/src/plugins/projectexplorer/customexecutablerunconfiguration.cpp
index dc353214b2..2890c8a7e4 100644
--- a/src/plugins/projectexplorer/customexecutablerunconfiguration.cpp
+++ b/src/plugins/projectexplorer/customexecutablerunconfiguration.cpp
@@ -141,7 +141,7 @@ QString CustomExecutableRunConfiguration::executable() const
 
         QString oldExecutable = m_executable;
         QString oldWorkingDirectory = m_workingDirectory;
-        QStringList oldCmdArguments = m_cmdArguments;
+        QString oldCmdArguments = m_cmdArguments;
 
         if (dialog.exec()) {
             return executable();
@@ -183,12 +183,7 @@ QString CustomExecutableRunConfiguration::baseWorkingDirectory() const
 }
 
 
-QStringList CustomExecutableRunConfiguration::commandLineArguments() const
-{
-    return environment().expandVariables(baseCommandLineArguments());
-}
-
-QStringList CustomExecutableRunConfiguration::baseCommandLineArguments() const
+QString CustomExecutableRunConfiguration::commandLineArguments() const
 {
     return m_cmdArguments;
 }
@@ -275,7 +270,7 @@ QVariantMap CustomExecutableRunConfiguration::toMap() const
 bool CustomExecutableRunConfiguration::fromMap(const QVariantMap &map)
 {
     m_executable = map.value(QLatin1String(EXECUTABLE_KEY)).toString();
-    m_cmdArguments = map.value(QLatin1String(ARGUMENTS_KEY)).toStringList();
+    m_cmdArguments = map.value(QLatin1String(ARGUMENTS_KEY)).toString();
     m_workingDirectory = map.value(QLatin1String(WORKING_DIRECTORY_KEY)).toString();
     m_runMode = map.value(QLatin1String(USE_TERMINAL_KEY)).toBool() ? Console : Gui;
     m_userEnvironmentChanges = Utils::EnvironmentItem::fromStringList(map.value(QLatin1String(USER_ENVIRONMENT_CHANGES_KEY)).toStringList());
@@ -294,9 +289,9 @@ void CustomExecutableRunConfiguration::setExecutable(const QString &executable)
     emit changed();
 }
 
-void CustomExecutableRunConfiguration::setBaseCommandLineArguments(const QString &commandLineArguments)
+void CustomExecutableRunConfiguration::setCommandLineArguments(const QString &commandLineArguments)
 {
-    m_cmdArguments = Utils::Environment::parseCombinedArgString(commandLineArguments);
+    m_cmdArguments = commandLineArguments;
     emit changed();
 }
 
diff --git a/src/plugins/projectexplorer/customexecutablerunconfiguration.h b/src/plugins/projectexplorer/customexecutablerunconfiguration.h
index f3287b65ba..debbba3ca0 100644
--- a/src/plugins/projectexplorer/customexecutablerunconfiguration.h
+++ b/src/plugins/projectexplorer/customexecutablerunconfiguration.h
@@ -69,7 +69,7 @@ public:
 
     LocalApplicationRunConfiguration::RunMode runMode() const;
     QString workingDirectory() const;
-    QStringList commandLineArguments() const;
+    QString commandLineArguments() const;
     Utils::Environment environment() const;
 
     QWidget *createConfigurationWidget();
@@ -108,8 +108,7 @@ private:
     QList<Utils::EnvironmentItem> userEnvironmentChanges() const;
 
     void setExecutable(const QString &executable);
-    void setBaseCommandLineArguments(const QString &commandLineArguments);
-    QStringList baseCommandLineArguments() const;
+    void setCommandLineArguments(const QString &commandLineArguments);
     QString baseWorkingDirectory() const;
     void setBaseWorkingDirectory(const QString &workingDirectory);
     void setUserName(const QString &name);
@@ -117,7 +116,7 @@ private:
 
     QString m_executable;
     QString m_workingDirectory;
-    QStringList m_cmdArguments;
+    QString m_cmdArguments;
     RunMode m_runMode;
     bool m_userSetName;
     QString m_userName;
diff --git a/src/plugins/projectexplorer/foldernavigationwidget.cpp b/src/plugins/projectexplorer/foldernavigationwidget.cpp
index 217d89173d..c4ffda2581 100644
--- a/src/plugins/projectexplorer/foldernavigationwidget.cpp
+++ b/src/plugins/projectexplorer/foldernavigationwidget.cpp
@@ -40,6 +40,7 @@
 #include <utils/environment.h>
 #include <utils/pathchooser.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/unixutils.h>
 #include <utils/consoleprocess.h>
 
@@ -438,8 +439,8 @@ void FolderNavigationWidget::openTerminal(const QString &path)
     const QString terminalEmulator = QString::fromLocal8Bit(qgetenv("COMSPEC"));
     const QStringList args; // none
 #else
-   QStringList args = Utils::ConsoleProcess::terminalEmulator(
-           Core::ICore::instance()->settings()).split(QLatin1Char(' '));
+    QStringList args = Utils::QtcProcess::splitArgs(
+        Utils::ConsoleProcess::terminalEmulator(Core::ICore::instance()->settings()));
     const QString terminalEmulator = args.takeFirst();
     const QString shell = QString::fromLocal8Bit(qgetenv("SHELL"));
     args.append(shell);
diff --git a/src/plugins/projectexplorer/localapplicationruncontrol.cpp b/src/plugins/projectexplorer/localapplicationruncontrol.cpp
index fda6752b7d..c7cd867def 100644
--- a/src/plugins/projectexplorer/localapplicationruncontrol.cpp
+++ b/src/plugins/projectexplorer/localapplicationruncontrol.cpp
@@ -78,7 +78,7 @@ LocalApplicationRunControl::LocalApplicationRunControl(LocalApplicationRunConfig
 {
     Utils::Environment env = rc->environment();
     QString dir = rc->workingDirectory();
-    m_applicationLauncher.setEnvironment(env.toStringList());
+    m_applicationLauncher.setEnvironment(env);
     m_applicationLauncher.setWorkingDirectory(dir);
 
     m_executable = rc->executable();
diff --git a/src/plugins/projectexplorer/localapplicationruncontrol.h b/src/plugins/projectexplorer/localapplicationruncontrol.h
index 3c546f0c3b..3445b05301 100644
--- a/src/plugins/projectexplorer/localapplicationruncontrol.h
+++ b/src/plugins/projectexplorer/localapplicationruncontrol.h
@@ -66,7 +66,7 @@ private slots:
 private:
     ProjectExplorer::ApplicationLauncher m_applicationLauncher;
     QString m_executable;
-    QStringList m_commandLineArguments;
+    QString m_commandLineArguments;
     ProjectExplorer::ApplicationLauncher::Mode m_runMode;
 };
 
diff --git a/src/plugins/projectexplorer/processstep.cpp b/src/plugins/projectexplorer/processstep.cpp
index eca3efb90f..3edb56e7de 100644
--- a/src/plugins/projectexplorer/processstep.cpp
+++ b/src/plugins/projectexplorer/processstep.cpp
@@ -33,6 +33,7 @@
 #include "buildconfiguration.h"
 
 #include <coreplugin/ifile.h>
+#include <utils/qtcprocess.h>
 #include <utils/qtcassert.h>
 
 #include <QtCore/QDebug>
@@ -124,7 +125,7 @@ QString ProcessStep::command() const
     return m_command;
 }
 
-QStringList ProcessStep::arguments() const
+QString ProcessStep::arguments() const
 {
     return m_arguments;
 }
@@ -144,7 +145,7 @@ void ProcessStep::setCommand(const QString &command)
     m_command = command;
 }
 
-void ProcessStep::setArguments(const QStringList &arguments)
+void ProcessStep::setArguments(const QString &arguments)
 {
     m_arguments = arguments;
 }
@@ -176,7 +177,7 @@ QVariantMap ProcessStep::toMap() const
 bool ProcessStep::fromMap(const QVariantMap &map)
 {
     setCommand(map.value(QLatin1String(PROCESS_COMMAND_KEY)).toString());
-    setArguments(map.value(QLatin1String(PROCESS_ARGUMENTS_KEY)).toStringList());
+    setArguments(map.value(QLatin1String(PROCESS_ARGUMENTS_KEY)).toString());
     setWorkingDirectory(map.value(QLatin1String(PROCESS_WORKINGDIRECTORY_KEY)).toString());
     setEnabled(map.value(QLatin1String(PROCESS_ENABLED_KEY), false).toBool());
     return AbstractProcessStep::fromMap(map);
@@ -277,7 +278,7 @@ void ProcessStepConfigWidget::updateDetails()
     m_summaryText = tr("<b>%1</b> %2 %3 %4")
                     .arg(displayName,
                          m_step->command(),
-                         m_step->arguments().join(QString(QLatin1Char(' '))),
+                         m_step->arguments(),
                          m_step->enabled() ? QString() : tr("(disabled)"));
     emit updateSummary();
 }
@@ -295,7 +296,7 @@ void ProcessStepConfigWidget::init()
     m_ui.workingDirectory->setEnvironment(m_step->buildConfiguration()->environment());
     m_ui.workingDirectory->setPath(m_step->workingDirectory());
 
-    m_ui.commandArgumentsLineEdit->setText(m_step->arguments().join(QString(QLatin1Char(' '))));
+    m_ui.commandArgumentsLineEdit->setText(m_step->arguments());
     m_ui.enabledCheckBox->setChecked(m_step->enabled());
 
     updateDetails();
@@ -319,8 +320,7 @@ void ProcessStepConfigWidget::workingDirectoryLineEditTextEdited()
 
 void ProcessStepConfigWidget::commandArgumentsLineEditTextEdited()
 {
-    m_step->setArguments(m_ui.commandArgumentsLineEdit->text().split(QLatin1Char(' '),
-          QString::SkipEmptyParts));
+    m_step->setArguments(m_ui.commandArgumentsLineEdit->text());
     updateDetails();
 }
 
diff --git a/src/plugins/projectexplorer/processstep.h b/src/plugins/projectexplorer/processstep.h
index e6c865cc14..f38ad0b7c7 100644
--- a/src/plugins/projectexplorer/processstep.h
+++ b/src/plugins/projectexplorer/processstep.h
@@ -73,12 +73,12 @@ public:
     virtual bool immutable() const;
 
     QString command() const;
-    QStringList arguments() const;
+    QString arguments() const;
     bool enabled() const;
     QString workingDirectory() const;
 
     void setCommand(const QString &command);
-    void setArguments(const QStringList &arguments);
+    void setArguments(const QString &arguments);
     void setEnabled(bool enabled);
     void setWorkingDirectory(const QString &workingDirectory);
 
@@ -94,7 +94,7 @@ private:
     void ctor();
 
     QString m_command;
-    QStringList m_arguments;
+    QString m_arguments;
     QString m_workingDirectory;
     Utils::Environment m_env;
     bool m_enabled;
diff --git a/src/plugins/projectexplorer/toolchain.cpp b/src/plugins/projectexplorer/toolchain.cpp
index 16ee9c4668..8fe844ddbe 100644
--- a/src/plugins/projectexplorer/toolchain.cpp
+++ b/src/plugins/projectexplorer/toolchain.cpp
@@ -35,8 +35,8 @@
 #include "msvcparser.h"
 #include "linuxiccparser.h"
 
-
 #include <utils/synchronousprocess.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QDebug>
 #include <QtCore/QFileInfo>
@@ -768,16 +768,16 @@ MSVCToolChain::StringStringPairList MSVCToolChain::readEnvironmentSettingI(const
     if (!tf.open())
         return StringStringPairList();
     const QString filename = tf.fileName();
-    QByteArray call = "call \"";
-    call +=  varsBat.toLocal8Bit();
-    call += '"';
+    QByteArray call = "call ";
+    call += Utils::QtcProcess::quoteArg(varsBat).toLocal8Bit();
     if (!args.isEmpty()) {
         call += ' ';
-        call += args.join(QString(QLatin1Char(' '))).toLocal8Bit();
+        call += Utils::QtcProcess::joinArgs(args).toLocal8Bit();
     }
     call += "\r\n";
     tf.write(call);
-    const QByteArray redirect = "set > \"" + QDir::toNativeSeparators(tempOutputFileName).toLocal8Bit() + "\"\r\n";
+    const QByteArray redirect = "set > " + Utils::QtcProcess::quoteArg(
+                QDir::toNativeSeparators(tempOutputFileName)).toLocal8Bit() + "\r\n";
     tf.write(redirect);
     tf.flush();
     tf.waitForBytesWritten(30000);
diff --git a/src/plugins/projectexplorer/winguiprocess.cpp b/src/plugins/projectexplorer/winguiprocess.cpp
index 3317ce317b..97e8170d70 100644
--- a/src/plugins/projectexplorer/winguiprocess.cpp
+++ b/src/plugins/projectexplorer/winguiprocess.cpp
@@ -30,6 +30,8 @@
 #include "winguiprocess.h"
 #include "consoleprocess.h"
 
+#include <utils/qtcprocess.h>
+
 #include <QtCore/QDir>
 
 using namespace ProjectExplorer::Internal;
@@ -46,7 +48,7 @@ WinGuiProcess::~WinGuiProcess()
     stop();
 }
 
-bool WinGuiProcess::start(const QString &program, const QStringList &args)
+bool WinGuiProcess::start(const QString &program, const QString &args)
 {
     m_program = program;
     m_args = args;
@@ -112,11 +114,14 @@ void WinGuiProcess::run()
 
         const bool dbgInterface = setupDebugInterface(bufferReadyEvent, dataReadyEvent, sharedFile, sharedMem);
 
-        const QString cmdLine = createWinCommandline(m_program, m_args);
+        QString pcmd, pargs;
+        QtcProcess::prepareCommand(m_program, m_args, &pcmd, &pargs, &m_environment, &m_workingDir);
+        const QString cmdLine = createWinCommandline(pcmd, pargs);
+        const QStringList env = m_environment.toStringList();
         started = CreateProcessW(0, (WCHAR*)cmdLine.utf16(),
                                       0, 0, TRUE, CREATE_UNICODE_ENVIRONMENT,
-                                      environment().isEmpty() ? 0
-                                          : createWinEnvironment(fixWinEnvironment(environment())).data(),
+                                      env.isEmpty() ? 0
+                                          : createWinEnvironment(fixWinEnvironment(env)).data(),
                                           workingDirectory().isEmpty() ? 0
                                               : (WCHAR*)QDir::convertSeparators(workingDirectory()).utf16(),
                                               &si, m_pid);
diff --git a/src/plugins/projectexplorer/winguiprocess.h b/src/plugins/projectexplorer/winguiprocess.h
index e729317dd2..3e63439018 100644
--- a/src/plugins/projectexplorer/winguiprocess.h
+++ b/src/plugins/projectexplorer/winguiprocess.h
@@ -53,7 +53,7 @@ public:
     explicit WinGuiProcess(QObject *parent = 0);
     virtual ~WinGuiProcess();
 
-    bool start(const QString &program, const QStringList &args);
+    bool start(const QString &program, const QString &args);
     void stop();
 
     bool isRunning() const;
@@ -71,7 +71,7 @@ private:
 
     PROCESS_INFORMATION *m_pid;
     QString m_program;
-    QStringList m_args;
+    QString m_args;
     unsigned long m_exitCode;
 };
 
diff --git a/src/plugins/qmljseditor/qmljspreviewrunner.cpp b/src/plugins/qmljseditor/qmljspreviewrunner.cpp
index 585b2e3b18..c16e528ed6 100644
--- a/src/plugins/qmljseditor/qmljspreviewrunner.cpp
+++ b/src/plugins/qmljseditor/qmljspreviewrunner.cpp
@@ -30,6 +30,7 @@
 #include "qmljspreviewrunner.h"
 
 #include <utils/environment.h>
+#include <utils/qtcprocess.h>
 #include <utils/synchronousprocess.h>
 
 #include <QtGui/QMessageBox>
@@ -50,7 +51,7 @@ QmlJSPreviewRunner::QmlJSPreviewRunner(QObject *parent) :
     m_qmlViewerDefaultPath = Utils::SynchronousProcess::locateBinary(searchPath, QLatin1String("qmlviewer"));
 
     Utils::Environment environment = Utils::Environment::systemEnvironment();
-    m_applicationLauncher.setEnvironment(environment.toStringList());
+    m_applicationLauncher.setEnvironment(environment);
 }
 
 bool QmlJSPreviewRunner::isReady() const
@@ -63,7 +64,7 @@ void QmlJSPreviewRunner::run(const QString &filename)
     QString errorMessage;
     if (!filename.isEmpty()) {
         m_applicationLauncher.start(ProjectExplorer::ApplicationLauncher::Gui, m_qmlViewerDefaultPath,
-                                    QStringList() << filename);
+                                    Utils::QtcProcess::quoteArg(filename));
 
     } else {
         errorMessage = "No file specified.";
diff --git a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
index 4c28260adc..5a51a0cea3 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
+++ b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
@@ -43,6 +43,7 @@
 #include <utils/debuggerlanguagechooser.h>
 #include <utils/detailswidget.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <qt4projectmanager/qtversionmanager.h>
 #include <qt4projectmanager/qt4projectmanagerconstants.h>
 #include <qt4projectmanager/qmlobservertool.h>
@@ -135,23 +136,20 @@ QString QmlProjectRunConfiguration::observerPath() const
     }
 }
 
-QStringList QmlProjectRunConfiguration::viewerArguments() const
+QString QmlProjectRunConfiguration::viewerArguments() const
 {
-    QStringList args;
-
     // arguments in .user file
-    if (!m_qmlViewerArgs.isEmpty())
-        args.append(m_qmlViewerArgs.split(QLatin1Char(' ')));
+    QString args = m_qmlViewerArgs;
 
     // arguments from .qmlproject file
     foreach (const QString &importPath, qmlTarget()->qmlProject()->importPaths()) {
-        args.append(QLatin1String("-I"));
-        args.append(importPath);
+        Utils::QtcProcess::addArg(&args, "-I");
+        Utils::QtcProcess::addArg(&args, importPath);
     }
 
-    const QString s = mainScript();
-    if (! s.isEmpty())
-        args.append(s);
+    const QString &s = mainScript();
+    if (!s.isEmpty())
+        Utils::QtcProcess::addArg(&args, s);
     return args;
 }
 
diff --git a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h
index 5942a76c0a..74d61dce6e 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h
+++ b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h
@@ -75,7 +75,7 @@ public:
 
     QString viewerPath() const;
     QString observerPath() const;
-    QStringList viewerArguments() const;
+    QString viewerArguments() const;
     QString workingDirectory() const;
     int qtVersionId() const;
     Qt4ProjectManager::QtVersion *qtVersion() const;
diff --git a/src/plugins/qmlprojectmanager/qmlprojectruncontrol.cpp b/src/plugins/qmlprojectmanager/qmlprojectruncontrol.cpp
index 861c58537c..cfaf92e77d 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectruncontrol.cpp
+++ b/src/plugins/qmlprojectmanager/qmlprojectruncontrol.cpp
@@ -37,6 +37,7 @@
 #include <qt4projectmanager/qtversionmanager.h>
 #include <utils/environment.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <debugger/debuggerrunner.h>
 #include <debugger/debuggerplugin.h>
@@ -64,7 +65,9 @@ QmlRunControl::QmlRunControl(QmlProjectRunConfiguration *runConfiguration, QStri
     : RunControl(runConfiguration, mode)
 {
     if (Qt4ProjectManager::QtVersion *qtVersion = runConfiguration->qtVersion())
-        m_applicationLauncher.setEnvironment(qtVersion->qmlToolsEnvironment().toStringList());
+        m_applicationLauncher.setEnvironment(qtVersion->qmlToolsEnvironment());
+    else
+        m_applicationLauncher.setEnvironment(Utils::Environment::systemEnvironment());
     m_applicationLauncher.setWorkingDirectory(runConfiguration->workingDirectory());
 
     if (mode == ProjectExplorer::Constants::RUNMODE) {
@@ -96,7 +99,7 @@ void QmlRunControl::start()
 
     emit started();
     emit appendMessage(this, tr("Starting %1 %2").arg(QDir::toNativeSeparators(m_executable),
-                                                      m_commandLineArguments.join(QLatin1String(" "))), false);
+                                                      m_commandLineArguments), false);
 }
 
 RunControl::StopResult QmlRunControl::stop()
@@ -200,10 +203,11 @@ ProjectExplorer::RunControl *QmlRunControlFactory::createDebugRunControl(QmlProj
     params.qmlServerAddress = "127.0.0.1";
     params.qmlServerPort = runConfig->qmlDebugServerPort();
     params.processArgs = runConfig->viewerArguments();
-    params.processArgs.append(QLatin1String("-qmljsdebugger=port:") + QString::number(runConfig->qmlDebugServerPort()));
+    Utils::QtcProcess::addArg(&params.processArgs,
+            QLatin1String("-qmljsdebugger=port:") + QString::number(runConfig->qmlDebugServerPort()));
     params.workingDirectory = runConfig->workingDirectory();
     if (Qt4ProjectManager::QtVersion *qtVersion = runConfig->qtVersion())
-        params.environment = qtVersion->qmlToolsEnvironment().toStringList();
+        params.environment = qtVersion->qmlToolsEnvironment();
     params.displayName = runConfig->displayName();
 
     if (params.executable.isEmpty()) {
diff --git a/src/plugins/qmlprojectmanager/qmlprojectruncontrol.h b/src/plugins/qmlprojectmanager/qmlprojectruncontrol.h
index 9254becabc..3d6c58588b 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectruncontrol.h
+++ b/src/plugins/qmlprojectmanager/qmlprojectruncontrol.h
@@ -61,7 +61,7 @@ private:
     ProjectExplorer::ApplicationLauncher m_applicationLauncher;
 
     QString m_executable;
-    QStringList m_commandLineArguments;
+    QString m_commandLineArguments;
 };
 
 class QmlRunControlFactory : public ProjectExplorer::IRunControlFactory {
diff --git a/src/plugins/qt4projectmanager/makestep.cpp b/src/plugins/qt4projectmanager/makestep.cpp
index 400b6ee6b7..7a34273cd0 100644
--- a/src/plugins/qt4projectmanager/makestep.cpp
+++ b/src/plugins/qt4projectmanager/makestep.cpp
@@ -43,6 +43,7 @@
 #include <projectexplorer/gnumakeparser.h>
 #include <projectexplorer/projectexplorer.h>
 #include <extensionsystem/pluginmanager.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QDir>
 #include <QtCore/QFileInfo>
@@ -113,7 +114,7 @@ QVariantMap MakeStep::toMap() const
 bool MakeStep::fromMap(const QVariantMap &map)
 {
     m_makeCmd = map.value(QLatin1String(MAKE_COMMAND_KEY)).toString();
-    m_userArgs = map.value(QLatin1String(MAKE_ARGUMENTS_KEY)).toStringList();
+    m_userArgs = map.value(QLatin1String(MAKE_ARGUMENTS_KEY)).toString();
     m_clean = map.value(QLatin1String(CLEAN_KEY)).toBool();
 
     return ProjectExplorer::AbstractProcessStep::fromMap(map);
@@ -150,22 +151,26 @@ bool MakeStep::init()
     // we should stop the clean queue
     // That is mostly so that rebuild works on a already clean project
     setIgnoreReturnValue(m_clean);
-    QStringList args;
+
+    QString args;
 
     ProjectExplorer::ToolChain *toolchain = bc->toolChain();
 
     if (bc->subNodeBuild()){
         if(!bc->subNodeBuild()->makefile().isEmpty()) {
-            args << "-f" << bc->subNodeBuild()->makefile();
+            Utils::QtcProcess::addArg(&args, QLatin1String("-f"));
+            Utils::QtcProcess::addArg(&args, bc->subNodeBuild()->makefile());
         }
     } else if (!bc->makefile().isEmpty()) {
-        args << "-f" << bc->makefile();
+        Utils::QtcProcess::addArg(&args, QLatin1String("-f"));
+        Utils::QtcProcess::addArg(&args, bc->makefile());
     }
 
-    args.append(m_userArgs);
+    Utils::QtcProcess::addArgs(&args, m_userArgs);
+
     if (!m_clean) {
         if (!bc->defaultMakeTarget().isEmpty())
-            args << bc->defaultMakeTarget();
+            Utils::QtcProcess::addArg(&args, bc->defaultMakeTarget());
     }
     // -w option enables "Enter"/"Leaving directory" messages, which we need for detecting the
     // absolute file path
@@ -177,7 +182,7 @@ bool MakeStep::init()
         if (toolchain->type() != ProjectExplorer::ToolChain_MSVC &&
             toolchain->type() != ProjectExplorer::ToolChain_WINCE) {
             if (m_makeCmd.isEmpty())
-                args << "-w";
+                Utils::QtcProcess::addArg(&args, QLatin1String("-w"));
         }
     }
 
@@ -235,12 +240,12 @@ ProjectExplorer::BuildStepConfigWidget *MakeStep::createConfigWidget()
     return new MakeStepConfigWidget(this);
 }
 
-QStringList MakeStep::userArguments()
+QString MakeStep::userArguments()
 {
     return m_userArgs;
 }
 
-void MakeStep::setUserArguments(const QStringList &arguments)
+void MakeStep::setUserArguments(const QString &arguments)
 {
     m_userArgs = arguments;
     emit userArgumentsChanged();
@@ -314,16 +319,16 @@ void MakeStepConfigWidget::updateDetails()
     // FIXME doing this without the user having a way to override this is rather bad
     // so we only do it for unix and if the user didn't override the make command
     // but for now this is the least invasive change
-    QStringList args = m_makeStep->userArguments();
+    QString args = m_makeStep->userArguments();
     ProjectExplorer::ToolChainType t = ProjectExplorer::ToolChain_UNKNOWN;
     ProjectExplorer::ToolChain *toolChain = bc->toolChain();
     if (toolChain)
         t = toolChain->type();
     if (t != ProjectExplorer::ToolChain_MSVC && t != ProjectExplorer::ToolChain_WINCE) {
         if (m_makeStep->m_makeCmd.isEmpty())
-            args << "-w";
+            Utils::QtcProcess::addArg(&args, QLatin1String("-w"));
     }
-    m_summaryText = tr("<b>Make:</b> %1 %2 in %3").arg(QFileInfo(makeCmd).fileName(), args.join(" "),
+    m_summaryText = tr("<b>Make:</b> %1 %2 in %3").arg(QFileInfo(makeCmd).fileName(), args,
                                                        QDir::toNativeSeparators(workingDirectory));
     emit updateSummary();
 }
@@ -342,8 +347,7 @@ void MakeStepConfigWidget::userArgumentsChanged()
 {
     if (m_ignoreChange)
         return;
-    const QStringList &makeArguments = m_makeStep->userArguments();
-    m_ui->makeArgumentsLineEdit->setText(Utils::Environment::joinArgumentList(makeArguments));
+    m_ui->makeArgumentsLineEdit->setText(m_makeStep->userArguments());
     updateDetails();
 }
 
@@ -354,8 +358,7 @@ void MakeStepConfigWidget::init()
     const QString &makeCmd = m_makeStep->m_makeCmd;
     m_ui->makePathChooser->setPath(makeCmd);
 
-    const QStringList &makeArguments = m_makeStep->userArguments();
-    m_ui->makeArgumentsLineEdit->setText(Utils::Environment::joinArgumentList(makeArguments));
+    m_ui->makeArgumentsLineEdit->setText(m_makeStep->userArguments());
     updateDetails();
 }
 
@@ -368,8 +371,7 @@ void MakeStepConfigWidget::makeEdited()
 void MakeStepConfigWidget::makeArgumentsLineEdited()
 {
     m_ignoreChange = true;
-    m_makeStep->setUserArguments(
-            Utils::Environment::parseCombinedArgString(m_ui->makeArgumentsLineEdit->text()));
+    m_makeStep->setUserArguments(m_ui->makeArgumentsLineEdit->text());
     m_ignoreChange = false;
     updateDetails();
 }
diff --git a/src/plugins/qt4projectmanager/makestep.h b/src/plugins/qt4projectmanager/makestep.h
index ee650b4136..0858e55fd9 100644
--- a/src/plugins/qt4projectmanager/makestep.h
+++ b/src/plugins/qt4projectmanager/makestep.h
@@ -91,8 +91,8 @@ public:
 
     virtual ProjectExplorer::BuildStepConfigWidget *createConfigWidget();
     virtual bool immutable() const;
-    QStringList userArguments();
-    void setUserArguments(const QStringList &arguments);
+    QString userArguments();
+    void setUserArguments(const QString &arguments);
     void setClean(bool clean);
 
     QVariantMap toMap() const;
@@ -108,7 +108,7 @@ protected:
 private:
     void ctor();
     bool m_clean;
-    QStringList m_userArgs;
+    QString m_userArgs;
     QString m_makeCmd;
     ProjectExplorer::GnuMakeParser * m_gnuMakeParser;
 };
diff --git a/src/plugins/qt4projectmanager/qmakestep.cpp b/src/plugins/qt4projectmanager/qmakestep.cpp
index 63753bb426..82a0ddc281 100644
--- a/src/plugins/qt4projectmanager/qmakestep.cpp
+++ b/src/plugins/qt4projectmanager/qmakestep.cpp
@@ -42,6 +42,7 @@
 
 #include <coreplugin/icore.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QDir>
 #include <QtCore/QFile>
@@ -100,29 +101,34 @@ Qt4BuildConfiguration *QMakeStep::qt4BuildConfiguration() const
 /// config arguemnts
 /// moreArguments
 /// user arguments
-QStringList QMakeStep::allArguments()
+QString QMakeStep::allArguments(bool shorted)
 {
-    QStringList additonalArguments = m_userArgs;
+    QString additonalArguments = m_userArgs;
     Qt4BuildConfiguration *bc = qt4BuildConfiguration();
     QStringList arguments;
     if (bc->subNodeBuild())
         arguments << QDir::toNativeSeparators(bc->subNodeBuild()->path());
+    else if (shorted)
+        arguments << QDir::toNativeSeparators(QFileInfo(
+                buildConfiguration()->target()->project()->file()->fileName()).fileName());
     else
         arguments << QDir::toNativeSeparators(buildConfiguration()->target()->project()->file()->fileName());
     arguments << "-r";
 
-    if (!additonalArguments.contains("-spec"))
-        arguments << "-spec" << bc->qtVersion()->mkspec();
+    for (Utils::QtcProcess::ArgIterator ait(&additonalArguments); ait.next(); )
+        if (ait.value() == QLatin1String("-spec"))
+            goto haveSpec;
+    arguments << "-spec" << bc->qtVersion()->mkspec();
+  haveSpec:
 
     // Find out what flags we pass on to qmake
     arguments << bc->configCommandLineArguments();
 
-    if (!additonalArguments.isEmpty())
-        arguments << additonalArguments;
-
     arguments << moreArguments();
 
-    return arguments;
+    QString args = Utils::QtcProcess::joinArgs(arguments);
+    Utils::QtcProcess::addArgs(&args, additonalArguments);
+    return args;
 }
 
 ///
@@ -164,7 +170,7 @@ bool QMakeStep::init()
     Qt4BuildConfiguration *qt4bc = qt4BuildConfiguration();
     const QtVersion *qtVersion = qt4bc->qtVersion();
 
-    QStringList args = allArguments();
+    QString args = allArguments();
     QString workingDirectory;
 
     if (qt4bc->subNodeBuild())
@@ -286,7 +292,7 @@ bool QMakeStep::processSucceeded(int exitCode, QProcess::ExitStatus status)
     return result;
 }
 
-void QMakeStep::setUserArguments(const QStringList &arguments)
+void QMakeStep::setUserArguments(const QString &arguments)
 {
     if (m_userArgs == arguments)
         return;
@@ -301,14 +307,13 @@ void QMakeStep::setUserArguments(const QStringList &arguments)
 QStringList QMakeStep::parserArguments()
 {
     QStringList result;
-    foreach (const QString &str, allArguments()) {
-        if (str.contains("="))
-            result << str;
-    }
+    for (Utils::QtcProcess::ConstArgIterator ait(allArguments()); ait.next(); )
+        if (ait.value().contains(QLatin1Char('=')))
+            result << ait.value();
     return result;
 }
 
-QStringList QMakeStep::userArguments()
+QString QMakeStep::userArguments()
 {
     return m_userArgs;
 }
@@ -322,7 +327,7 @@ QVariantMap QMakeStep::toMap() const
 
 bool QMakeStep::fromMap(const QVariantMap &map)
 {
-    m_userArgs = map.value(QLatin1String(QMAKE_ARGUMENTS_KEY)).toStringList();
+    m_userArgs = map.value(QLatin1String(QMAKE_ARGUMENTS_KEY)).toString();
 
     return BuildStep::fromMap(map);
 }
@@ -349,8 +354,7 @@ QMakeStepConfigWidget::QMakeStepConfigWidget(QMakeStep *step)
 
 void QMakeStepConfigWidget::init()
 {
-    QString qmakeArgs = Utils::Environment::joinArgumentList(m_step->userArguments());
-    m_ui.qmakeAdditonalArgumentsLineEdit->setText(qmakeArgs);
+    m_ui.qmakeAdditonalArgumentsLineEdit->setText(m_step->userArguments());
 
     qmakeBuildConfigChanged();
 
@@ -393,8 +397,7 @@ void QMakeStepConfigWidget::userArgumentsChanged()
 {
     if (m_ignoreChange)
         return;
-    QString qmakeArgs = Utils::Environment::joinArgumentList(m_step->userArguments());
-    m_ui.qmakeAdditonalArgumentsLineEdit->setText(qmakeArgs);
+    m_ui.qmakeAdditonalArgumentsLineEdit->setText(m_step->userArguments());
     updateSummaryLabel();
     updateEffectiveQMakeCall();
 }
@@ -402,8 +405,7 @@ void QMakeStepConfigWidget::userArgumentsChanged()
 void QMakeStepConfigWidget::qmakeArgumentsLineEdited()
 {
     m_ignoreChange = true;
-    m_step->setUserArguments(
-            Utils::Environment::parseCombinedArgString(m_ui.qmakeAdditonalArgumentsLineEdit->text()));
+    m_step->setUserArguments(m_ui.qmakeAdditonalArgumentsLineEdit->text());
     m_ignoreChange = false;
 
     updateSummaryLabel();
@@ -446,16 +448,11 @@ void QMakeStepConfigWidget::updateSummaryLabel()
         return;
     }
 
-    QStringList args = m_step->allArguments();
     // We don't want the full path to the .pro file
-    const QString projectFileName = m_step->buildConfiguration()->target()->project()->file()->fileName();
-    int index = args.indexOf(projectFileName);
-    if (index != -1)
-        args[index] = QFileInfo(projectFileName).fileName();
-
+    QString args = m_step->allArguments(true);
     // And we only use the .pro filename not the full path
     QString program = QFileInfo(qtVersion->qmakeCommand()).fileName();
-    m_summaryText = tr("<b>qmake:</b> %1 %2").arg(program, args.join(QString(QLatin1Char(' '))));
+    m_summaryText = tr("<b>qmake:</b> %1 %2").arg(program, args);
     emit updateSummary();
 
 }
@@ -465,7 +462,7 @@ void QMakeStepConfigWidget::updateEffectiveQMakeCall()
     Qt4BuildConfiguration *qt4bc = m_step->qt4BuildConfiguration();
     const QtVersion *qtVersion = qt4bc->qtVersion();
     QString program = QFileInfo(qtVersion->qmakeCommand()).fileName();
-    m_ui.qmakeArgumentsEdit->setPlainText(program + QLatin1Char(' ') + Utils::Environment::joinArgumentList(m_step->allArguments()));
+    m_ui.qmakeArgumentsEdit->setPlainText(program + QLatin1Char(' ') + m_step->allArguments());
 }
 
 ////
diff --git a/src/plugins/qt4projectmanager/qmakestep.h b/src/plugins/qt4projectmanager/qmakestep.h
index 0f3c00c3ee..09befadf73 100644
--- a/src/plugins/qt4projectmanager/qmakestep.h
+++ b/src/plugins/qt4projectmanager/qmakestep.h
@@ -86,11 +86,11 @@ public:
     bool forced();
 
     // TODO clean up those functions
-    QStringList allArguments();
+    QString allArguments(bool shorted = false);
     QStringList moreArguments();
     QStringList parserArguments();
-    QStringList userArguments();
-    void setUserArguments(const QStringList &arguments);
+    QString userArguments();
+    void setUserArguments(const QString &arguments);
 
     QVariantMap toMap() const;
 
@@ -112,7 +112,7 @@ private:
     QStringList m_lastEnv;
     bool m_forced;
     bool m_needToRunQMake; // set in init(), read in run()
-    QStringList m_userArgs;
+    QString m_userArgs;
     bool m_scriptTemplate;
     QList<ProjectExplorer::Task> m_tasks;
 };
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemodebugsupport.cpp b/src/plugins/qt4projectmanager/qt-maemo/maemodebugsupport.cpp
index 4b2ac4e5b9..2c2e6156a8 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemodebugsupport.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemodebugsupport.cpp
@@ -270,7 +270,7 @@ void MaemoDebugSupport::startDebugging()
         const QString cmdPrefix = MaemoGlobal::remoteCommandPrefix(remoteExe);
         const QString env
             = environment(m_debuggingType, m_runner->userEnvChanges());
-        const QString args = m_runner->arguments().join(QLatin1String(" "));
+        const QString args = m_runner->arguments();
         const QString remoteCommandLine
             = m_debuggingType == MaemoRunConfiguration::DebugQmlOnly
                 ? QString::fromLocal8Bit("%1 %2 %3 %4").arg(cmdPrefix).arg(env)
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.cpp b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.cpp
index 39e74db339..fe118baee0 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.cpp
@@ -49,6 +49,7 @@
 #include <qt4projectmanager/qt4project.h>
 
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtCore/QStringBuilder>
 
@@ -185,7 +186,7 @@ bool MaemoRunConfiguration::fromMap(const QVariantMap &map)
     if (!RunConfiguration::fromMap(map))
         return false;
 
-    m_arguments = map.value(ArgumentsKey).toStringList();
+    m_arguments = map.value(ArgumentsKey).toString();
     const QDir dir = QDir(target()->project()->projectDirectory());
     m_proFilePath = dir.filePath(map.value(ProFileKey).toString());
     m_useRemoteGdb = map.value(UseRemoteGdbKey, DefaultUseRemoteGdbValue).toBool();
@@ -262,7 +263,7 @@ const QString MaemoRunConfiguration::targetRoot() const
     return QString();
 }
 
-const QStringList MaemoRunConfiguration::arguments() const
+const QString MaemoRunConfiguration::arguments() const
 {
     return m_arguments;
 }
@@ -334,7 +335,7 @@ bool MaemoRunConfiguration::useRemoteGdb() const
     return m_useRemoteGdb && toolchain()->allowsRemoteMounts();
 }
 
-void MaemoRunConfiguration::setArguments(const QStringList &args)
+void MaemoRunConfiguration::setArguments(const QString &args)
 {
     m_arguments = args;
 }
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.h b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.h
index 0288b08a82..883fef516a 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.h
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfiguration.h
@@ -92,8 +92,8 @@ public:
     QString remoteExecutableFilePath() const;
     const QString sysRoot() const;
     const QString targetRoot() const;
-    const QStringList arguments() const;
-    void setArguments(const QStringList &args);
+    const QString arguments() const;
+    void setArguments(const QString &args);
     MaemoDeviceConfig deviceConfig() const;
     MaemoPortList freePorts() const;
     bool useRemoteGdb() const;
@@ -149,7 +149,7 @@ private:
     QString m_proFilePath;
     mutable QString m_gdbPath;
     MaemoRemoteMountsModel *m_remoteMounts;
-    QStringList m_arguments;
+    QString m_arguments;
     bool m_useRemoteGdb;
 
     BaseEnvironmentBase m_baseEnvironmentBase;
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfigurationwidget.cpp b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfigurationwidget.cpp
index d2a8799e92..1b1f6eea49 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemorunconfigurationwidget.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemorunconfigurationwidget.cpp
@@ -137,7 +137,7 @@ void MaemoRunConfigurationWidget::addGenericWidgets(QVBoxLayout *mainLayout)
     formLayout->addRow(tr("Executable on host:"), m_localExecutableLabel);
     m_remoteExecutableLabel = new QLabel;
     formLayout->addRow(tr("Executable on device:"), m_remoteExecutableLabel);
-    m_argsLineEdit = new QLineEdit(m_runConfiguration->arguments().join(" "));
+    m_argsLineEdit = new QLineEdit(m_runConfiguration->arguments());
     formLayout->addRow(tr("Arguments:"), m_argsLineEdit);
 
     QHBoxLayout * const debugButtonsLayout = new QHBoxLayout;
@@ -293,7 +293,7 @@ void MaemoRunConfigurationWidget::addEnvironmentWidgets(QVBoxLayout *mainLayout)
 
 void MaemoRunConfigurationWidget::argumentsEdited(const QString &text)
 {
-    m_runConfiguration->setArguments(text.split(' ', QString::SkipEmptyParts));
+    m_runConfiguration->setArguments(text);
 }
 
 void MaemoRunConfigurationWidget::updateTargetInformation()
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemoruncontrol.cpp b/src/plugins/qt4projectmanager/qt-maemo/maemoruncontrol.cpp
index aabc0c2c24..388450e41c 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemoruncontrol.cpp
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemoruncontrol.cpp
@@ -104,7 +104,7 @@ void MaemoRunControl::startExecution()
         .arg(MaemoGlobal::remoteCommandPrefix(m_runner->remoteExecutable()))
         .arg(MaemoGlobal::remoteEnvironment(m_runner->userEnvChanges()))
         .arg(m_runner->remoteExecutable())
-        .arg(m_runner->arguments().join(QLatin1String(" "))).toUtf8());
+        .arg(m_runner->arguments()).toUtf8());
 }
 
 void MaemoRunControl::handleRemoteProcessFinished(qint64 exitCode)
diff --git a/src/plugins/qt4projectmanager/qt-maemo/maemosshrunner.h b/src/plugins/qt4projectmanager/qt-maemo/maemosshrunner.h
index 94828e5385..dba27d2e18 100644
--- a/src/plugins/qt4projectmanager/qt-maemo/maemosshrunner.h
+++ b/src/plugins/qt4projectmanager/qt-maemo/maemosshrunner.h
@@ -74,7 +74,7 @@ public:
     MaemoPortList *freePorts() { return &m_freePorts; }
     MaemoDeviceConfig deviceConfig() const { return m_devConfig; }
     QString remoteExecutable() const { return m_remoteExecutable; }
-    QStringList arguments() const { return m_appArguments; }
+    QString arguments() const { return m_appArguments; }
     QList<Utils::EnvironmentItem> userEnvChanges() const { return m_userEnvChanges; }
 
     static const qint64 InvalidExitCode;
@@ -118,7 +118,7 @@ private:
     MaemoUsedPortsGatherer * const m_portsGatherer;
     const MaemoDeviceConfig m_devConfig;
     const QString m_remoteExecutable;
-    const QStringList m_appArguments;
+    const QString m_appArguments;
     const QList<Utils::EnvironmentItem> m_userEnvChanges;
     const MaemoPortList m_initialFreePorts;
     QList<MaemoMountSpecification> m_mountSpecs;
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.cpp b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.cpp
index 8958d5686e..128a96347e 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.cpp
@@ -225,7 +225,7 @@ bool S60DeviceRunConfiguration::fromMap(const QVariantMap &map)
     const QDir projectDir = QDir(target()->project()->projectDirectory());
 
     m_proFilePath = projectDir.filePath(map.value(QLatin1String(PRO_FILE_KEY)).toString());
-    m_commandLineArguments = map.value(QLatin1String(COMMAND_LINE_ARGUMENTS_KEY)).toStringList();
+    m_commandLineArguments = map.value(QLatin1String(COMMAND_LINE_ARGUMENTS_KEY)).toString();
 
     if (m_proFilePath.isEmpty())
         return false;
@@ -368,12 +368,12 @@ QString S60DeviceRunConfiguration::projectFilePath() const
     return m_proFilePath;
 }
 
-QStringList S60DeviceRunConfiguration::commandLineArguments() const
+QString S60DeviceRunConfiguration::commandLineArguments() const
 {
     return m_commandLineArguments;
 }
 
-void S60DeviceRunConfiguration::setCommandLineArguments(const QStringList &args)
+void S60DeviceRunConfiguration::setCommandLineArguments(const QString &args)
 {
     m_commandLineArguments = args;
 }
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.h b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.h
index bee69b71ec..8e0b479feb 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.h
+++ b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfiguration.h
@@ -77,8 +77,8 @@ public:
 
     ProjectExplorer::OutputFormatter *createOutputFormatter() const;
 
-    QStringList commandLineArguments() const;
-    void setCommandLineArguments(const QStringList &args);
+    QString commandLineArguments() const;
+    void setCommandLineArguments(const QString &args);
 
     QString projectFilePath() const;
 
@@ -112,7 +112,7 @@ private:
     void handleParserState(bool sucess);
 
     QString m_proFilePath;
-    QStringList m_commandLineArguments;
+    QString m_commandLineArguments;
     bool m_validParse;
 };
 
@@ -184,7 +184,7 @@ private:
     QString m_serialPortName;
     QString m_serialPortFriendlyName;
     QString m_targetName;
-    QStringList m_commandLineArguments;
+    QString m_commandLineArguments;
     QString m_executableFileName;
     QString m_qtDir;
     QString m_qtBinPath;
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfigurationwidget.cpp b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfigurationwidget.cpp
index 339343dfac..7aa0c2d705 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfigurationwidget.cpp
+++ b/src/plugins/qt4projectmanager/qt-s60/s60devicerunconfigurationwidget.cpp
@@ -46,7 +46,7 @@ S60DeviceRunConfigurationWidget::S60DeviceRunConfigurationWidget(
     : QWidget(parent),
     m_runConfiguration(runConfiguration),
     m_detailsWidget(new Utils::DetailsWidget),
-    m_argumentsLineEdit(new QLineEdit(m_runConfiguration->commandLineArguments().join(QString(QLatin1Char(' ')))))
+    m_argumentsLineEdit(new QLineEdit(m_runConfiguration->commandLineArguments()))
 {
     m_detailsWidget->setState(Utils::DetailsWidget::NoSummary);
     QVBoxLayout *mainBoxLayout = new QVBoxLayout();
@@ -76,13 +76,7 @@ S60DeviceRunConfigurationWidget::S60DeviceRunConfigurationWidget(
 
 void S60DeviceRunConfigurationWidget::argumentsEdited(const QString &text)
 {
-    const QString trimmed = text.trimmed();
-    if (trimmed.isEmpty()) {
-        m_runConfiguration->setCommandLineArguments(QStringList());
-    } else {
-        m_runConfiguration->setCommandLineArguments(trimmed.split(QLatin1Char(' '),
-                                                                  QString::SkipEmptyParts));
-    }
+    m_runConfiguration->setCommandLineArguments(text.trimmed());
 }
 
 void S60DeviceRunConfigurationWidget::runConfigurationEnabledChange(bool enabled)
diff --git a/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.cpp b/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.cpp
index d01a368653..2fb2d1c6fe 100644
--- a/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt-s60/s60emulatorrunconfiguration.cpp
@@ -327,7 +327,7 @@ S60EmulatorRunControl::S60EmulatorRunControl(S60EmulatorRunConfiguration *runCon
     // stuff like the EPOCROOT and EPOCDEVICE env variable
     Utils::Environment env = Utils::Environment::systemEnvironment();
     runConfiguration->qt4Target()->activeBuildConfiguration()->toolChain()->addToEnvironment(env);
-    m_applicationLauncher.setEnvironment(env.toStringList());
+    m_applicationLauncher.setEnvironment(env);
 
     m_executable = runConfiguration->executable();
     connect(&m_applicationLauncher, SIGNAL(applicationError(QString)),
@@ -342,7 +342,7 @@ S60EmulatorRunControl::S60EmulatorRunControl(S60EmulatorRunConfiguration *runCon
 
 void S60EmulatorRunControl::start()
 {
-    m_applicationLauncher.start(ApplicationLauncher::Gui, m_executable, QStringList());
+    m_applicationLauncher.start(ApplicationLauncher::Gui, m_executable, QString());
     emit started();
 
     emit appendMessage(this, tr("Starting %1...").arg(QDir::toNativeSeparators(m_executable)), false);
diff --git a/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp b/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
index d19abc99fa..54cb7f8294 100644
--- a/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt4buildconfiguration.cpp
@@ -37,6 +37,7 @@
 #include "makestep.h"
 
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <limits>
 #include <projectexplorer/buildsteplist.h>
 #include <projectexplorer/projectexplorerconstants.h>
@@ -494,7 +495,7 @@ bool Qt4BuildConfiguration::compareToImportFrom(const QString &makefile)
         QtVersion *version = qtVersion();
         if (version->qmakeCommand() == qmakePath) {
             // same qtversion
-            QPair<QtVersion::QmakeBuildConfigs, QStringList> result =
+            QPair<QtVersion::QmakeBuildConfigs, QString> result =
                     QtVersionManager::scanMakeFile(makefile, version->defaultBuildConfig());
             if (qmakeBuildConfiguration() == result.first) {
                 // The qmake Build Configuration are the same,
@@ -502,18 +503,18 @@ bool Qt4BuildConfiguration::compareToImportFrom(const QString &makefile)
                 // we have to compare without the spec/platform cmd argument
                 // and compare that on its own
                 QString workingDirectory = QFileInfo(makefile).absolutePath();
-                QString actualSpec = extractSpecFromArgumentList(qs->userArguments(), workingDirectory, version);
+                QString userArgs = qs->userArguments();
+                QStringList actualArgs;
+                QString actualSpec = extractSpecFromArguments(&userArgs, workingDirectory, version, &actualArgs);
                 if (actualSpec.isEmpty()) {
                     // Easy one: the user has chosen not to override the settings
                     actualSpec = version->mkspec();
                 }
+                actualArgs += qs->moreArguments();
 
-
-                QString parsedSpec = extractSpecFromArgumentList(result.second, workingDirectory, version);
-                QStringList actualArgs = qs->moreArguments();
-                actualArgs << qs->userArguments();
-                actualArgs = removeSpecFromArgumentList(actualArgs);
-                QStringList parsedArgs = removeSpecFromArgumentList(result.second);
+                QString qmakeArgs = result.second;
+                QStringList parsedArgs;
+                QString parsedSpec = extractSpecFromArguments(&qmakeArgs, workingDirectory, version, &parsedArgs);
 
                 if (debug) {
                     qDebug()<<"Actual args:"<<actualArgs;
@@ -558,59 +559,53 @@ bool Qt4BuildConfiguration::compareToImportFrom(const QString &makefile)
     return false;
 }
 
-QStringList Qt4BuildConfiguration::removeQMLInspectorFromArgumentList(const QStringList &old)
+void Qt4BuildConfiguration::removeQMLInspectorFromArguments(QString *args)
 {
-    QStringList result;
-    foreach (const QString &str, old)
-        if (!str.startsWith(QLatin1String(Constants::QMAKEVAR_QMLJSDEBUGGER_PATH)))
-            result << str;
-    return result;
+    for (Utils::QtcProcess::ArgIterator ait(args); ait.next(); )
+        if (ait.value().startsWith(QLatin1String(Constants::QMAKEVAR_QMLJSDEBUGGER_PATH)))
+            ait.deleteArg();
 }
 
-// We match -spec and -platfrom separetly
-// We ignore -cache, because qmake contained a bug that it didn't
-// mention the -cache in the Makefile
-// That means changing the -cache option in the additional arguments
-// does not automatically rerun qmake. Alas, we could try more
-// intelligent matching for -cache, but i guess people rarely
-// do use that.
-
-QStringList Qt4BuildConfiguration::removeSpecFromArgumentList(const QStringList &old)
+QString Qt4BuildConfiguration::extractSpecFromArguments(QString *args,
+                                                        const QString &directory, const QtVersion *version,
+                                                        QStringList *outArgs)
 {
-    if (!old.contains("-spec") && !old.contains("-platform") && !old.contains("-cache"))
-        return old;
-    QStringList newList;
+    QString parsedSpec;
+
     bool ignoreNext = false;
-    foreach(const QString &item, old) {
+    bool nextIsSpec = false;
+    for (Utils::QtcProcess::ArgIterator ait(args); ait.next(); ) {
         if (ignoreNext) {
             ignoreNext = false;
-        } else if (item == "-spec" || item == "-platform" || item == "-cache") {
+            ait.deleteArg();
+        } else if (nextIsSpec) {
+            nextIsSpec = false;
+            parsedSpec = QDir::cleanPath(ait.value());
+            ait.deleteArg();
+        } else if (ait.value() == QLatin1String("-spec") || ait.value() == QLatin1String("-platform")) {
+            nextIsSpec = true;
+            ait.deleteArg();
+        } else if (ait.value() == QLatin1String("-cache")) {
+            // We ignore -cache, because qmake contained a bug that it didn't
+            // mention the -cache in the Makefile.
+            // That means changing the -cache option in the additional arguments
+            // does not automatically rerun qmake. Alas, we could try more
+            // intelligent matching for -cache, but i guess people rarely
+            // do use that.
             ignoreNext = true;
-        } else {
-            newList << item;
+            ait.deleteArg();
+        } else if (outArgs && ait.isSimple()) {
+            outArgs->append(ait.value());
         }
     }
-    return newList;
-}
-
-QString Qt4BuildConfiguration::extractSpecFromArgumentList(const QStringList &list, QString directory, QtVersion *version)
-{
-    int index = list.indexOf("-spec");
-    if (index == -1)
-        index = list.indexOf("-platform");
-    if (index == -1)
-        return QString();
-
-    ++index;
 
-    if (index >= list.length())
+    if (parsedSpec.isEmpty())
         return QString();
 
     QString baseMkspecDir = version->versionInfo().value("QMAKE_MKSPECS");
     if (baseMkspecDir.isEmpty())
         baseMkspecDir = version->versionInfo().value("QT_INSTALL_DATA") + "/mkspecs";
 
-    QString parsedSpec = QDir::cleanPath(list.at(index));
 #ifdef Q_OS_WIN
     baseMkspecDir = baseMkspecDir.toLower();
     parsedSpec = parsedSpec.toLower();
@@ -753,12 +748,12 @@ BuildConfiguration *Qt4BuildConfigurationFactory::create(ProjectExplorer::Target
     qt4Target->addQt4BuildConfiguration(tr("%1 Debug").arg(buildConfigurationName),
                                         version,
                                         (version->defaultBuildConfig() | QtVersion::DebugBuild),
-                                        QStringList(), QString());
+                                        QString(), QString());
     BuildConfiguration *bc =
     qt4Target->addQt4BuildConfiguration(tr("%1 Release").arg(buildConfigurationName),
                                         version,
                                         (version->defaultBuildConfig() & ~QtVersion::DebugBuild),
-                                        QStringList(), QString());
+                                        QString(), QString());
     return bc;
 }
 
diff --git a/src/plugins/qt4projectmanager/qt4buildconfiguration.h b/src/plugins/qt4projectmanager/qt4buildconfiguration.h
index 956c95e73c..2a1940bbfe 100644
--- a/src/plugins/qt4projectmanager/qt4buildconfiguration.h
+++ b/src/plugins/qt4projectmanager/qt4buildconfiguration.h
@@ -109,9 +109,10 @@ public:
     QString makefile() const;
 
     bool compareToImportFrom(const QString &makefile);
-    static QStringList removeQMLInspectorFromArgumentList(const QStringList &old);
-    static QStringList removeSpecFromArgumentList(const QStringList &old);
-    static QString extractSpecFromArgumentList(const QStringList &list, QString directory, QtVersion *version);
+    static void removeQMLInspectorFromArguments(QString *args);
+    static QString extractSpecFromArguments(QString *arguments,
+                                            const QString &directory, const QtVersion *version,
+                                            QStringList *outArgs = 0);
 
     QVariantMap toMap() const;
 
diff --git a/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp b/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
index 081a20d2ae..1056bf935d 100644
--- a/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
+++ b/src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp
@@ -43,6 +43,7 @@
 #include <projectexplorer/projectexplorerconstants.h>
 #include <projectexplorer/buildconfiguration.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <extensionsystem/pluginmanager.h>
 
 #include <QtGui/QFileDialog>
@@ -416,20 +417,22 @@ void Qt4ProjectConfigWidget::importLabelClicked()
                 vm->addVersion(version);
             }
 
-            QPair<QtVersion::QmakeBuildConfigs, QStringList> result =
+            QPair<QtVersion::QmakeBuildConfigs, QString> result =
                     QtVersionManager::scanMakeFile(directory, version->defaultBuildConfig());
             QtVersion::QmakeBuildConfigs qmakeBuildConfig = result.first;
-            QStringList additionalArguments = Qt4BuildConfiguration::removeSpecFromArgumentList(result.second);
-            QString parsedSpec = Qt4BuildConfiguration::extractSpecFromArgumentList(result.second, directory, version);
+
+            QString aa = result.second;
+            QString parsedSpec = Qt4BuildConfiguration::extractSpecFromArguments(&aa, directory, version);
             QString versionSpec = version->mkspec();
+            QString additionalArguments;
             if (parsedSpec.isEmpty() || parsedSpec == versionSpec || parsedSpec == "default") {
                 // using the default spec, don't modify additional arguments
             } else {
-                additionalArguments.prepend(parsedSpec);
-                additionalArguments.prepend("-spec");
+                additionalArguments = "-spec " + Utils::QtcProcess::quoteArg(parsedSpec);
             }
+            Utils::QtcProcess::addArgs(&additionalArguments, aa);
 
-            additionalArguments = Qt4BuildConfiguration::removeQMLInspectorFromArgumentList(additionalArguments);
+            Qt4BuildConfiguration::removeQMLInspectorFromArguments(&additionalArguments);
 
             // So we got all the information now apply it...
             m_buildConfiguration->setQtVersion(version);
@@ -443,16 +446,25 @@ void Qt4ProjectConfigWidget::importLabelClicked()
             // If we are switching to BuildAll we want "release" in there and no "debug"
             // or "debug" in there and no "release"
             // If we are switching to not BuildAl we want neither "release" nor "debug" in there
-            QStringList makeCmdArguments = makeStep->userArguments();
             bool debug = qmakeBuildConfig & QtVersion::DebugBuild;
-            if (qmakeBuildConfig & QtVersion::BuildAll) {
-                makeCmdArguments.removeAll(debug ? "release" : "debug");
-                if (!makeCmdArguments.contains(debug ? "debug" : "release"))
-                    makeCmdArguments.append(debug ? "debug" : "release");
-            } else {
-                makeCmdArguments.removeAll("debug");
-                makeCmdArguments.removeAll("release");
+            bool haveTag = !(qmakeBuildConfig & QtVersion::BuildAll);
+            QString makeCmdArguments = makeStep->userArguments();
+            Utils::QtcProcess::ArgIterator ait(&makeCmdArguments);
+            while (ait.next()) {
+                if (ait.value() == QLatin1String("debug")) {
+                    if (!haveTag && debug)
+                        haveTag = true;
+                    else
+                        ait.deleteArg();
+                } else if (ait.value() == QLatin1String("release")) {
+                    if (!haveTag && !debug)
+                        haveTag = true;
+                    else
+                        ait.deleteArg();
+                }
             }
+            if (!haveTag)
+                ait.appendArg(QLatin1String(debug ? "debug" : "release"));
             makeStep->setUserArguments(makeCmdArguments);
         }
     }
diff --git a/src/plugins/qt4projectmanager/qt4runconfiguration.cpp b/src/plugins/qt4projectmanager/qt4runconfiguration.cpp
index 132d7be6bd..5866a02e56 100644
--- a/src/plugins/qt4projectmanager/qt4runconfiguration.cpp
+++ b/src/plugins/qt4projectmanager/qt4runconfiguration.cpp
@@ -47,6 +47,7 @@
 #include <projectexplorer/environmenteditmodel.h>
 #include <projectexplorer/persistentsettings.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #include <utils/pathchooser.h>
 #include <utils/detailswidget.h>
 #include <utils/debuggerlanguagechooser.h>
@@ -220,7 +221,7 @@ Qt4RunConfigurationWidget::Qt4RunConfigurationWidget(Qt4RunConfiguration *qt4Run
     toplayout->addRow(tr("Executable:"), m_executableLineEdit);
 
     QLabel *argumentsLabel = new QLabel(tr("Arguments:"), this);
-    m_argumentsLineEdit = new QLineEdit(Utils::Environment::joinArgumentList(qt4RunConfiguration->baseCommandLineArguments()), this);
+    m_argumentsLineEdit = new QLineEdit(qt4RunConfiguration->commandLineArguments(), this);
     argumentsLabel->setBuddy(m_argumentsLineEdit);
     toplayout->addRow(argumentsLabel, m_argumentsLineEdit);
 
@@ -326,7 +327,7 @@ Qt4RunConfigurationWidget::Qt4RunConfigurationWidget(Qt4RunConfiguration *qt4Run
     connect(qt4RunConfiguration, SIGNAL(baseWorkingDirectoryChanged(QString)),
             this, SLOT(workingDirectoryChanged(QString)));
 
-    connect(qt4RunConfiguration, SIGNAL(baseCommandLineArgumentsChanged(QString)),
+    connect(qt4RunConfiguration, SIGNAL(commandLineArgumentsChanged(QString)),
             this, SLOT(commandLineArgumentsChanged(QString)));
     connect(qt4RunConfiguration, SIGNAL(runModeChanged(ProjectExplorer::LocalApplicationRunConfiguration::RunMode)),
             this, SLOT(runModeChanged(ProjectExplorer::LocalApplicationRunConfiguration::RunMode)));
@@ -424,7 +425,7 @@ void Qt4RunConfigurationWidget::workingDirectoryReseted()
 void Qt4RunConfigurationWidget::argumentsEdited(const QString &args)
 {
     m_ignoreChange = true;
-    m_qt4RunConfiguration->setBaseCommandLineArguments(args);
+    m_qt4RunConfiguration->setCommandLineArguments(args);
     m_ignoreChange = false;
 }
 
@@ -514,7 +515,7 @@ QVariantMap Qt4RunConfiguration::toMap() const
 bool Qt4RunConfiguration::fromMap(const QVariantMap &map)
 {
     const QDir projectDir = QDir(target()->project()->projectDirectory());
-    m_commandLineArguments = map.value(QLatin1String(COMMAND_LINE_ARGUMENTS_KEY)).toStringList();
+    m_commandLineArguments = map.value(QLatin1String(COMMAND_LINE_ARGUMENTS_KEY)).toString();
     m_proFilePath = projectDir.filePath(map.value(QLatin1String(PRO_FILE_KEY)).toString());
     m_runMode = map.value(QLatin1String(USE_TERMINAL_KEY), false).toBool() ? Console : Gui;
     m_isUsingDyldImageSuffix = map.value(QLatin1String(USE_DYLD_IMAGE_SUFFIX_KEY), false).toBool();
@@ -573,12 +574,7 @@ QString Qt4RunConfiguration::baseWorkingDirectory() const
     return ti.workingDir;
 }
 
-QStringList Qt4RunConfiguration::commandLineArguments() const
-{
-    return environment().expandVariables(baseCommandLineArguments());
-}
-
-QStringList Qt4RunConfiguration::baseCommandLineArguments() const
+QString Qt4RunConfiguration::commandLineArguments() const
 {
     return m_commandLineArguments;
 }
@@ -651,10 +647,10 @@ void Qt4RunConfiguration::setBaseWorkingDirectory(const QString &wd)
         emit baseWorkingDirectoryChanged(newWorkingDirectory);
 }
 
-void Qt4RunConfiguration::setBaseCommandLineArguments(const QString &argumentsString)
+void Qt4RunConfiguration::setCommandLineArguments(const QString &argumentsString)
 {
-    m_commandLineArguments = Utils::Environment::parseCombinedArgString(argumentsString);
-    emit baseCommandLineArgumentsChanged(argumentsString);
+    m_commandLineArguments = argumentsString;
+    emit commandLineArgumentsChanged(argumentsString);
 }
 
 void Qt4RunConfiguration::setRunMode(RunMode runMode)
diff --git a/src/plugins/qt4projectmanager/qt4runconfiguration.h b/src/plugins/qt4projectmanager/qt4runconfiguration.h
index 413f214253..3a57cc87f4 100644
--- a/src/plugins/qt4projectmanager/qt4runconfiguration.h
+++ b/src/plugins/qt4projectmanager/qt4runconfiguration.h
@@ -84,7 +84,7 @@ public:
     virtual QString executable() const;
     virtual RunMode runMode() const;
     virtual QString workingDirectory() const;
-    virtual QStringList commandLineArguments() const;
+    virtual QString commandLineArguments() const;
     virtual Utils::Environment environment() const;
     virtual QString dumperLibrary() const;
     virtual QStringList dumperLibraryLocations() const;
@@ -101,7 +101,7 @@ public:
     ProjectExplorer::OutputFormatter *createOutputFormatter() const;
 
 signals:
-    void baseCommandLineArgumentsChanged(const QString&);
+    void commandLineArgumentsChanged(const QString&);
     void baseWorkingDirectoryChanged(const QString&);
     void runModeChanged(ProjectExplorer::LocalApplicationRunConfiguration::RunMode runMode);
     void usingDyldImageSuffixChanged(bool);
@@ -124,8 +124,7 @@ private:
     void setRunMode(RunMode runMode);
     void setBaseWorkingDirectory(const QString &workingDirectory);
     QString baseWorkingDirectory() const;
-    void setBaseCommandLineArguments(const QString &argumentsString);
-    QStringList baseCommandLineArguments() const;
+    void setCommandLineArguments(const QString &argumentsString);
     enum BaseEnvironmentBase { CleanEnvironmentBase = 0,
                                SystemEnvironmentBase = 1,
                                BuildEnvironmentBase  = 2 };
@@ -141,7 +140,7 @@ private:
     QList<Utils::EnvironmentItem> userEnvironmentChanges() const;
 
     void updateTarget();
-    QStringList m_commandLineArguments;
+    QString m_commandLineArguments;
     QString m_proFilePath; // Full path to the Application Pro File
 
     // Cached startup sub project information
diff --git a/src/plugins/qt4projectmanager/qt4target.cpp b/src/plugins/qt4projectmanager/qt4target.cpp
index ccdbbc6b22..e154d20ae7 100644
--- a/src/plugins/qt4projectmanager/qt4target.cpp
+++ b/src/plugins/qt4projectmanager/qt4target.cpp
@@ -274,7 +274,7 @@ Qt4Project *Qt4Target::qt4Project() const
 
 Qt4BuildConfiguration *Qt4Target::addQt4BuildConfiguration(QString displayName, QtVersion *qtversion,
                                                            QtVersion::QmakeBuildConfigs qmakeBuildConfiguration,
-                                                           QStringList additionalArguments,
+                                                           QString additionalArguments,
                                                            QString directory)
 {
     Q_ASSERT(qtversion);
@@ -297,14 +297,14 @@ Qt4BuildConfiguration *Qt4Target::addQt4BuildConfiguration(QString displayName,
 
     MakeStep* cleanStep = new MakeStep(cleanSteps);
     cleanStep->setClean(true);
-    cleanStep->setUserArguments(QStringList() << "clean");
+    cleanStep->setUserArguments("clean");
     cleanSteps->insertStep(0, cleanStep);
     if (!additionalArguments.isEmpty())
         qmakeStep->setUserArguments(additionalArguments);
 
     // set some options for qmake and make
     if (qmakeBuildConfiguration & QtVersion::BuildAll) // debug_and_release => explicit targets
-        makeStep->setUserArguments(QStringList() << (debug ? "debug" : "release"));
+        makeStep->setUserArguments(debug ? "debug" : "release");
 
     bc->setQMakeBuildConfiguration(qmakeBuildConfiguration);
 
diff --git a/src/plugins/qt4projectmanager/qt4target.h b/src/plugins/qt4projectmanager/qt4target.h
index fa5c1cca85..d6df4457c5 100644
--- a/src/plugins/qt4projectmanager/qt4target.h
+++ b/src/plugins/qt4projectmanager/qt4target.h
@@ -47,12 +47,12 @@ class Qt4DeployConfigurationFactory;
 
 struct BuildConfigurationInfo {
     explicit BuildConfigurationInfo(QtVersion *v = 0, QtVersion::QmakeBuildConfigs bc = QtVersion::QmakeBuildConfig(0),
-                                    const QStringList &aa = QStringList(), const QString &d = QString()) :
+                                    const QString &aa = QString(), const QString &d = QString()) :
         version(v), buildConfig(bc), additionalArguments(aa), directory(d)
     { }
     QtVersion *version;
     QtVersion::QmakeBuildConfigs buildConfig;
-    QStringList additionalArguments;
+    QString additionalArguments;
     QString directory;
 };
 
@@ -71,7 +71,7 @@ public:
     Internal::Qt4BuildConfiguration *addQt4BuildConfiguration(QString displayName,
                                                               QtVersion *qtversion,
                                                               QtVersion::QmakeBuildConfigs qmakeBuildConfiguration,
-                                                              QStringList additionalArguments,
+                                                              QString additionalArguments,
                                                               QString directory);
     void addRunConfigurationForPath(const QString &proFilePath);
 
diff --git a/src/plugins/qt4projectmanager/qtversionmanager.cpp b/src/plugins/qt4projectmanager/qtversionmanager.cpp
index ff9fb7ad4d..16867f7278 100644
--- a/src/plugins/qt4projectmanager/qtversionmanager.cpp
+++ b/src/plugins/qt4projectmanager/qtversionmanager.cpp
@@ -49,6 +49,7 @@
 #include <coreplugin/helpmanager.h>
 #include <extensionsystem/pluginmanager.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 #ifdef Q_OS_WIN
 #    include <utils/winutils.h>
 #endif
@@ -884,25 +885,21 @@ bool QtVersionManager::makefileIsFor(const QString &makefile, const QString &pro
     return srcFileInfo == proFileInfo;
 }
 
-QPair<QtVersion::QmakeBuildConfigs, QStringList> QtVersionManager::scanMakeFile(const QString &makefile, QtVersion::QmakeBuildConfigs defaultBuildConfig)
+QPair<QtVersion::QmakeBuildConfigs, QString> QtVersionManager::scanMakeFile(const QString &makefile, QtVersion::QmakeBuildConfigs defaultBuildConfig)
 {
     if (debug)
         qDebug()<<"ScanMakeFile, the gory details:";
     QtVersion::QmakeBuildConfigs result = defaultBuildConfig;
-    QStringList result2;
+    QString result2;
 
     QString line = findQMakeLine(makefile, QLatin1String("# Command:"));
     if (!line.isEmpty()) {
         if (debug)
             qDebug()<<"Found line"<<line;
         line = trimLine(line);
-        QStringList parts = splitLine(line);
-        if (debug)
-            qDebug()<<"Split into"<<parts;
         QList<QMakeAssignment> assignments;
         QList<QMakeAssignment> afterAssignments;
-        QStringList additionalArguments;
-        parseParts(parts, &assignments, &afterAssignments, &additionalArguments);
+        parseArgs(line, &assignments, &afterAssignments, &result2);
 
         if (debug) {
             dumpQMakeAssignments(assignments);
@@ -918,13 +915,12 @@ QPair<QtVersion::QmakeBuildConfigs, QStringList> QtVersionManager::scanMakeFile(
         if (debug)
             dumpQMakeAssignments(assignments);
 
-        result2.append(additionalArguments);
         foreach(const QMakeAssignment &qa, assignments)
-            result2.append(qa.variable + qa.op + qa.value);
+            Utils::QtcProcess::addArg(&result2, qa.variable + qa.op + qa.value);
         if (!afterAssignments.isEmpty()) {
-            result2.append("-after");
+            Utils::QtcProcess::addArg(&result2, QLatin1String("-after"));
             foreach(const QMakeAssignment &qa, afterAssignments)
-                result2.append(qa.variable + qa.op + qa.value);
+                Utils::QtcProcess::addArg(&result2, qa.variable + qa.op + qa.value);
         }
     }
 
@@ -965,55 +961,23 @@ QString QtVersionManager::trimLine(const QString line)
     return line.mid(firstSpace).trimmed();
 }
 
-QStringList QtVersionManager::splitLine(const QString &line)
-{
-    // Split on each " ", except on those which are escaped
-    // On Unix also remove all escaping
-    // On Windows also, but different escaping
-    bool escape = false;
-    QString currentWord;
-    QStringList results;
-    int length = line.length();
-    for (int i=0; i<length; ++i) {
-#ifdef Q_OS_WIN
-        if (line.at(i) == '"') {
-            escape = !escape;
-        } else if (escape || line.at(i) != ' ') {
-            currentWord += line.at(i);
-        } else {
-            results << currentWord;
-            currentWord.clear();;
-        }
-#else
-        if (escape) {
-            currentWord += line.at(i);
-            escape = false;
-        } else if (line.at(i) == ' ') {
-            results << currentWord;
-            currentWord.clear();
-        } else if (line.at(i) == '\\') {
-            escape = true;
-        } else {
-            currentWord += line.at(i);
-        }
-#endif
-    }
-    return results;
-}
-
-void QtVersionManager::parseParts(const QStringList &parts, QList<QMakeAssignment> *assignments, QList<QMakeAssignment> *afterAssignments, QStringList *additionalArguments)
+void QtVersionManager::parseArgs(const QString &args, QList<QMakeAssignment> *assignments, QList<QMakeAssignment> *afterAssignments, QString *additionalArguments)
 {
     QRegExp regExp("([^\\s\\+-]*)\\s*(\\+=|=|-=|~=)(.*)");
     bool after = false;
     bool ignoreNext = false;
-    foreach (const QString &part, parts) {
+    *additionalArguments = args;
+    Utils::QtcProcess::ArgIterator ait(additionalArguments);
+    while (ait.next()) {
         if (ignoreNext) {
             // Ignoring
             ignoreNext = false;
-        } else if (part == "-after") {
+            ait.deleteArg();
+        } else if (ait.value() == QLatin1String("-after")) {
             after = true;
-        } else if(part.contains('=')) {
-            if (regExp.exactMatch(part)) {
+            ait.deleteArg();
+        } else if (ait.value().contains(QLatin1Char('='))) {
+            if (regExp.exactMatch(ait.value())) {
                 QMakeAssignment qa;
                 qa.variable = regExp.cap(1);
                 qa.op = regExp.cap(2);
@@ -1025,21 +989,23 @@ void QtVersionManager::parseParts(const QStringList &parts, QList<QMakeAssignmen
             } else {
                 qDebug()<<"regexp did not match";
             }
-        } else if (part == "-o") {
+            ait.deleteArg();
+        } else if (ait.value() == QLatin1String("-o")) {
             ignoreNext = true;
-        } else {
-            additionalArguments->append(part);
-        }
-    }
+            ait.deleteArg();
 #if defined(Q_OS_WIN32)
-    additionalArguments->removeAll("-win32");
+        } else if (ait.value() == QLatin1String("-win32")) {
 #elif defined(Q_OS_MAC)
-    additionalArguments->removeAll("-macx");
+        } else if (ait.value() == QLatin1String("-macx")) {
 #elif defined(Q_OS_QNX6)
-    additionalArguments->removeAll("-qnx6");
+        } else if (ait.value() == QLatin1String("-qnx6")) {
 #else
-    additionalArguments->removeAll("-unix");
+        } else if (ait.value() == QLatin1String("-unix")) {
 #endif
+            ait.deleteArg();
+        }
+    }
+    ait.deleteArg();  // The .pro file is always the last arg
 }
 
 /// This function extracts all the CONFIG+=debug, CONFIG+=release
diff --git a/src/plugins/qt4projectmanager/qtversionmanager.h b/src/plugins/qt4projectmanager/qtversionmanager.h
index 90d52c95ab..9462a7ffb4 100644
--- a/src/plugins/qt4projectmanager/qtversionmanager.h
+++ b/src/plugins/qt4projectmanager/qtversionmanager.h
@@ -265,9 +265,9 @@ public:
 
     // Static Methods
     static bool makefileIsFor(const QString &makefile, const QString &proFile);
-    static QPair<QtVersion::QmakeBuildConfigs, QStringList> scanMakeFile(const QString &makefile,
-                                                                         QtVersion::QmakeBuildConfigs defaultBuildConfig);
-    static QString findQMakeBinaryFromMakefile(const QString &makefile);
+    static QPair<QtVersion::QmakeBuildConfigs, QString> scanMakeFile(const QString &makefile,
+                                                                     QtVersion::QmakeBuildConfigs defaultBuildConfig);
+    static QString findQMakeBinaryFromMakefile(const QString &directory);
     bool isValidId(int id) const;
 
 signals:
@@ -281,11 +281,10 @@ private:
     static bool equals(QtVersion *a, QtVersion *b);
     static QString findQMakeLine(const QString &directory, const QString &key);
     static QString trimLine(const QString line);
-    static QStringList splitLine(const QString &line);
-    static void parseParts(const QStringList &parts,
-                           QList<QMakeAssignment> *assignments,
-                           QList<QMakeAssignment> *afterAssignments,
-                           QStringList *additionalArguments);
+    static void parseArgs(const QString &args,
+                          QList<QMakeAssignment> *assignments,
+                          QList<QMakeAssignment> *afterAssignments,
+                          QString *additionalArguments);
     static QtVersion::QmakeBuildConfigs qmakeBuildConfigFromCmdArgs(QList<QMakeAssignment> *assignments,
                                                                     QtVersion::QmakeBuildConfigs defaultBuildConfig);
     // Used by QtOptionsPage
diff --git a/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp b/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
index 227b0b5946..601472054e 100644
--- a/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
+++ b/src/plugins/qt4projectmanager/wizards/targetsetuppage.cpp
@@ -40,6 +40,7 @@
 #include <projectexplorer/task.h>
 #include <projectexplorer/taskhub.h>
 #include <utils/qtcassert.h>
+#include <utils/qtcprocess.h>
 
 #include <QtGui/QAction>
 #include <QtGui/QFileDialog>
@@ -415,21 +416,20 @@ TargetSetupPage::recursivelyCheckDirectoryForBuild(const QString &directory, con
         info.isTemporary = true;
     }
 
-    QPair<QtVersion::QmakeBuildConfigs, QStringList> result =
+    QPair<QtVersion::QmakeBuildConfigs, QString> result =
             QtVersionManager::scanMakeFile(directory + "/Makefile", info.version->defaultBuildConfig());
     info.buildConfig = result.first;
-    info.additionalArguments = Qt4BuildConfiguration::removeSpecFromArgumentList(result.second);
-
-    QString parsedSpec = Qt4BuildConfiguration::extractSpecFromArgumentList(result.second, directory, info.version);
+    QString aa = result.second;
+    QString parsedSpec = Qt4BuildConfiguration::extractSpecFromArguments(&aa, directory, info.version);
     QString versionSpec = info.version->mkspec();
 
     // Compare mkspecs and add to additional arguments
     if (parsedSpec.isEmpty() || parsedSpec == versionSpec || parsedSpec == "default") {
         // using the default spec, don't modify additional arguments
     } else {
-        info.additionalArguments.prepend(parsedSpec);
-        info.additionalArguments.prepend("-spec");
+        info.additionalArguments = "-spec " + Utils::QtcProcess::quoteArg(parsedSpec);
     }
+    Utils::QtcProcess::addArgs(&info.additionalArguments, aa);
 
     results.append(info);
     return results;
diff --git a/src/plugins/qt4projectmanager/wizards/targetsetuppage.h b/src/plugins/qt4projectmanager/wizards/targetsetuppage.h
index e29b9343b7..e354e6a243 100644
--- a/src/plugins/qt4projectmanager/wizards/targetsetuppage.h
+++ b/src/plugins/qt4projectmanager/wizards/targetsetuppage.h
@@ -87,7 +87,7 @@ public:
         QtVersion *version;
         bool isTemporary;
         QtVersion::QmakeBuildConfigs buildConfig;
-        QStringList additionalArguments;
+        QString additionalArguments;
         QString directory;
         bool isExistingBuild;
         bool isShadowBuild;