Meson build plugin initial support

Most basic project management is implemented:
- Project config/build
- Build options accessible to user
- Lists most build targets
- Meson and Ninja added to kit setup
- Basic project file tree with files known by Meson
- Some basic meson and ninja process output parsing
- Some project templates

Missing features, that will come later:
- Configurable project tree layout
- Locators for Meson
- Build importer
- Access to Machine files for better user fine tuning
- ...

Fixes: QTCREATORBUG-18117
Change-Id: I2811e71562c113fb0fc6b6177bcf0698fa71ef63
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/mesonprojectmanager/exewrappers/toolwrapper.cpp

@@ -0,0 +1,84 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Alexis Jeandet.
+** 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 "toolwrapper.h"
+
+namespace MesonProjectManager {
+namespace Internal {
+
+ToolWrapper::ToolWrapper(const QString &name, const Utils::FilePath &path, bool autoDetected)
+    : m_version(read_version(path))
+    , m_isValid{path.exists() && m_version.isValid}
+    , m_autoDetected{autoDetected}
+    , m_id{Core::Id::fromString(QUuid::createUuid().toString())}
+    , m_exe{path}
+    , m_name{name}
+{}
+
+ToolWrapper::ToolWrapper(const QString &name,
+                         const Utils::FilePath &path,
+                         const Core::Id &id,
+                         bool autoDetected)
+    : m_version(read_version(path))
+    , m_isValid{path.exists() && m_version.isValid}
+    , m_autoDetected{autoDetected}
+    , m_id{id}
+    , m_exe{path}
+    , m_name{name}
+{
+    QTC_ASSERT(m_id.isValid(), m_id = Core::Id::fromString(QUuid::createUuid().toString()));
+}
+
+void ToolWrapper::setExe(const Utils::FilePath &newExe)
+{
+    m_exe = newExe;
+    m_version = read_version(m_exe);
+}
+
+Version ToolWrapper::read_version(const Utils::FilePath &toolPath)
+{
+    if (toolPath.toFileInfo().isExecutable()) {
+        QProcess process;
+        process.start(toolPath.toString(), {"--version"});
+        if (process.waitForFinished()) {
+            return Version::fromString(QString::fromUtf8(process.readLine()));
+        }
+    }
+    return {};
+}
+
+Utils::optional<Utils::FilePath> ToolWrapper::findTool(const QStringList &exeNames)
+{
+    using namespace Utils;
+    Environment systemEnvironment = Environment::systemEnvironment();
+    for (const auto &exe : exeNames) {
+        const FilePath exe_path = systemEnvironment.searchInPath(exe);
+        if (exe_path.exists())
+            return exe_path;
+    }
+    return Utils::nullopt;
+}
+
+} // namespace Internal
+} // namespace MesonProjectManager