Python: add pyside uic extra compiler

To be able to autocomplete code from .ui forms we need to feed the
python language server the compiled form. The uic extra compiler
generates a temporary ui_name.py file for uncompiled or unsaved ui
files. These files are inside a folder that gets appended to the python
path environment variable for the python language server.

Change-Id: I9f48d2012162f33986639315189c41e0a7e0dad2
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/python/pysideuicextracompiler.cpp

@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2022 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include "pysideuicextracompiler.h"
+
+#include <utils/qtcprocess.h>
+
+using namespace ProjectExplorer;
+
+namespace Python {
+namespace Internal {
+
+PySideUicExtraCompiler::PySideUicExtraCompiler(const Utils::FilePath &pySideUic,
+                                               const Project *project,
+                                               const Utils::FilePath &source,
+                                               const Utils::FilePaths &targets,
+                                               QObject *parent)
+    : ProcessExtraCompiler(project, source, targets, parent)
+    , m_pySideUic(pySideUic)
+{
+}
+
+Utils::FilePath PySideUicExtraCompiler::pySideUicPath() const
+{
+    return m_pySideUic;
+}
+
+Utils::FilePath PySideUicExtraCompiler::command() const
+{
+    return m_pySideUic;
+}
+
+FileNameToContentsHash PySideUicExtraCompiler::handleProcessFinished(
+    Utils::QtcProcess *process)
+{
+    FileNameToContentsHash result;
+    if (process->exitStatus() != QProcess::NormalExit && process->exitCode() != 0)
+        return result;
+
+    const Utils::FilePaths targetList = targets();
+    if (targetList.size() != 1)
+        return result;
+    // As far as I can discover in the UIC sources, it writes out local 8-bit encoding. The
+    // conversion below is to normalize both the encoding, and the line terminators.
+    result[targetList.first()] = QString::fromLocal8Bit(process->readAllStandardOutput()).toUtf8();
+    return result;
+}
+
+} // namespace Internal
+} // namespace Python