Terminal: Enable TerminalProcessInterface

Adds a new helper app "process_stub" that replaces the previous.
"process_stub_unix/win". The purpose was and is to allow processes
to be "injected" into other hosts apps like terminals while still
being able to control and debug them.

A new base class called "TerminalInterface" is used for both the new
Terminal plugin and the legacy TerminalProcess implementation.

Fixes: QTCREATORBUG-16364
Change-Id: If21273fe53ad545d1a768c17c83db4bf2fd85395
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/terminal/terminalprocessimpl.cpp

@@ -0,0 +1,67 @@
+// Copyright (C) 2022 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
+
+#include "terminalprocessimpl.h"
+#include "terminalwidget.h"
+
+#include <QCoreApplication>
+#include <QLocalServer>
+#include <QLocalSocket>
+#include <QLoggingCategory>
+#include <QTemporaryFile>
+#include <QTimer>
+
+Q_LOGGING_CATEGORY(terminalProcessLog, "qtc.terminal.stubprocess", QtDebugMsg)
+
+using namespace Utils;
+using namespace Utils::Terminal;
+
+namespace Terminal {
+
+class ProcessStubCreator : public StubCreator
+{
+public:
+    ProcessStubCreator(TerminalProcessImpl *interface, TerminalPane *terminalPane)
+        : m_terminalPane(terminalPane)
+        , m_process(interface)
+    {}
+
+    void startStubProcess(const CommandLine &cmd, const ProcessSetupData &setup) override
+    {
+        const Id id = Id::fromString(setup.m_commandLine.executable().toUserOutput());
+
+        TerminalWidget *terminal = m_terminalPane->stoppedTerminalWithId(id);
+
+        const OpenTerminalParameters openParameters{cmd,
+                                                    std::nullopt,
+                                                    std::nullopt,
+                                                    ExitBehavior::Keep,
+                                                    id};
+
+        if (!terminal) {
+            terminal = new TerminalWidget(nullptr, openParameters);
+
+            terminal->setShellName(setup.m_commandLine.executable().fileName());
+            m_terminalPane->addTerminal(terminal, "App");
+        } else {
+            terminal->restart(openParameters);
+        }
+
+        connect(terminal, &TerminalWidget::destroyed, m_process, [process = m_process] {
+            if (process->inferiorProcessId())
+                process->emitFinished(-1, QProcess::CrashExit);
+        });
+    }
+
+    TerminalPane *m_terminalPane;
+    TerminalProcessImpl *m_process;
+};
+
+TerminalProcessImpl::TerminalProcessImpl(TerminalPane *terminalPane)
+{
+    auto creator = new ProcessStubCreator(this, terminalPane);
+    creator->moveToThread(qApp->thread());
+    setStubCreator(creator);
+}
+
+} // namespace Terminal