CppTools: Refactor ProjectPartBuilder

...and add some basic tests.

Introduce the abstractions ProjectInterface and ToolChainInterface in
order to break the dependency to the ProjectExplorer. Also, some simple
logic can go there to simplify the (Base)ProjectPartBuilder.

Change-Id: I6c50a1804ce62098b87109931eb171f5c2542937
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/cppprojectinterface.h

@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 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.
+**
+****************************************************************************/
+
+#pragma once
+
+#include <projectexplorer/toolchain.h>
+
+#include <memory>
+
+QT_BEGIN_NAMESPACE
+class QString;
+QT_END_NAMESPACE
+
+namespace Core {
+class Id;
+}
+
+namespace ProjectExplorer {
+class Project;
+class ToolChain;
+}
+
+namespace CppTools {
+
+class ToolChainInterface
+{
+public:
+    virtual ~ToolChainInterface() {}
+
+    virtual Core::Id type() const = 0;
+    virtual bool isMsvc2015Toolchain() const = 0;
+
+    virtual unsigned wordWidth() const = 0;
+    virtual QString targetTriple() const = 0;
+
+    virtual QByteArray predefinedMacros() const = 0;
+    virtual QList<ProjectExplorer::HeaderPath> systemHeaderPaths() const = 0;
+
+    virtual ProjectExplorer::WarningFlags warningFlags() const = 0;
+    virtual ProjectExplorer::ToolChain::CompilerFlags compilerFlags() const = 0;
+};
+
+using ToolChainInterfacePtr = std::unique_ptr<ToolChainInterface>;
+
+class ProjectInterface
+{
+public:
+    virtual ~ProjectInterface() {}
+
+    virtual QString displayName() const = 0;
+    virtual QString projectFilePath() const = 0;
+
+    virtual ToolChainInterfacePtr toolChain(ProjectExplorer::ToolChain::Language language,
+                                            const QStringList &commandLineFlags) const = 0;
+};
+
+} // namespace CppTools