Utils: Introduce QtcProcess::toStandaloneCommandLine()

The goal is to make a QtcProcess incl. environment, working directory,
executable and arguments testable, e.g. in a terminal. The new
toStandaloneCommandLine() returns a string containing the command line
for a call of "env" the data of the QtcProcess instance as parameters.

To be used like:
  qDebug().noquote() << qtcProc.toStandaloneCommandLine();

..and the debug output can be pasted into a terminal.

Change-Id: Ib6cbea290e1eff3279d6e0a67076a624312af879
Reviewed-by: hjk <hjk@qt.io>

src/libs/utils/qtcprocess.cpp

@@ -832,6 +832,25 @@ void QtcProcess::setStandardInputFile(const QString &inputFile)
     d->m_process->setStandardInputFile(inputFile);
 }
 
+QString QtcProcess::toStandaloneCommandLine() const
+{
+    QStringList parts;
+    parts.append("/usr/bin/env");
+    if (!d->m_workingDirectory.isEmpty()) {
+        parts.append("-C");
+        d->m_workingDirectory.path();
+    }
+    parts.append("-i");
+    if (d->m_environment.size() > 0) {
+        const QStringList envVars = d->m_environment.toStringList();
+        std::transform(envVars.cbegin(), envVars.cend(),
+                       std::back_inserter(parts), ProcessArgs::quoteArgUnix);
+    }
+    parts.append(d->m_commandLine.executable().path());
+    parts.append(d->m_commandLine.splitArguments());
+    return parts.join(" ");
+}
+
 void QtcProcess::setRemoteProcessHooks(const DeviceProcessHooks &hooks)
 {
     s_deviceHooks = hooks;

src/libs/utils/qtcprocess.h

@@ -193,6 +193,8 @@ public:
 
     void setStandardInputFile(const QString &inputFile);
 
+    QString toStandaloneCommandLine() const;
+
 signals:
     void started();
     void finished();