Clang: Improve interfaces

The interfaces should never used to handle ownership. So it is now using
protected destructors. Copy operations are forbidden too.

https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#c35-a-base-class-destructor-should-be-either-public-and-virtual-or-protected-and-nonvirtual

Change-Id: Ib0b60a73a7ec130973b5cb0095cc5b2f10fa0758
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangrefactoring/clangrefactoring-source.pri

@@ -39,7 +39,5 @@ SOURCES += \
     $$PWD/refactoringconnectionclient.cpp \
     $$PWD/refactoringengine.cpp \
     $$PWD/refactoringprojectupdater.cpp \
-    $$PWD/searchinterface.cpp \
     $$PWD/searchhandle.cpp \
-    $$PWD/symbolsfindfilter.cpp \
-    $$PWD/projectpartproviderinterface.cpp
+    $$PWD/symbolsfindfilter.cpp

src/plugins/clangrefactoring/projectpartproviderinterface.cpp

@@ -1,32 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2017 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 "projectpartproviderinterface.h"
-
-namespace ClangRefactoring {
-
-ProjectPartProviderInterface::~ProjectPartProviderInterface() = default;
-
-} // namespace ClangRefactoring

src/plugins/clangrefactoring/projectpartproviderinterface.h

@@ -39,7 +39,6 @@ class ProjectPartProviderInterface
 {
 public:
     ProjectPartProviderInterface() = default;
-    virtual ~ProjectPartProviderInterface();
 
     ProjectPartProviderInterface(const ProjectPartProviderInterface&) = delete;
     ProjectPartProviderInterface& operator=(const ProjectPartProviderInterface&) = delete;
@@ -49,6 +48,9 @@ public:
 
     virtual CppTools::ProjectPart *projectPart(const QString &projectPartId) const = 0;
     virtual ClangBackEnd::V2::FileContainers generatedFiles() const = 0;
+
+protected:
+    ~ProjectPartProviderInterface() = default;
 };
 
 } // namespace ClangRefactoring

src/plugins/clangrefactoring/searchhandle.h

@@ -34,6 +34,10 @@ namespace ClangRefactoring {
 class SearchHandle
 {
 public:
+    SearchHandle() = default;
+    SearchHandle(const SearchHandle &) = delete;
+    SearchHandle &operator=(const SearchHandle &) = delete;
+
     virtual ~SearchHandle();
 
     virtual void addResult(const QString &fileName,

src/plugins/clangrefactoring/searchinterface.h

@@ -36,9 +36,15 @@ namespace ClangRefactoring {
 class SearchInterface
 {
 public:
-    virtual ~SearchInterface();
+    SearchInterface() = default;
+    SearchInterface(const SearchInterface &) = delete;
+    SearchInterface &operator=(const SearchInterface &) = delete;
+
     virtual std::unique_ptr<SearchHandle> startNewSearch(const QString &searchLabel,
-                                                                  const QString &searchTerm) = 0;
+                                                         const QString &searchTerm) = 0;
+
+protected:
+    ~SearchInterface() = default;
 };
 
 } // namespace ClangRefactoring

src/plugins/clangrefactoring/symbolqueryinterface.h

@@ -47,7 +47,10 @@ enum class SymbolType
 class SymbolQueryInterface
 {
 public:
-    virtual ~SymbolQueryInterface() {}
+    SymbolQueryInterface() = default;
+    SymbolQueryInterface(const SymbolQueryInterface &) = delete;
+    SymbolQueryInterface &operator=(const SymbolQueryInterface &) = delete;
+
     virtual SourceLocations locationsAt(ClangBackEnd::FilePathId filePathId,
                                         int line,
                                         int utf8Column) const = 0;
@@ -57,6 +60,9 @@ public:
     virtual Symbols symbolsContaining(SymbolType symbolType,
                                       Utils::SmallStringView regularExpression) const = 0;
     virtual Functions functionsContaining(Utils::SmallStringView regularExpression) const = 0;
+
+protected:
+    ~SymbolQueryInterface() = default;
 };
 
 } // namespace ClangRefactoring