Clang: Add clang query

Clang query is mechanism to use AST matcher to search for code. Think
about regular expression but in the context of AST. So you get a semantic
search tool for C++.

Change-Id: I72e882c5b53a0c52f352a3664847c4c3e4f6fc2e
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/tools/clangrefactoringbackend/source/clangquery.h

@@ -0,0 +1,73 @@
+/****************************************************************************
+**
+** 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 "clangtool.h"
+
+#include <sourcerangescontainer.h>
+#include <dynamicastmatcherdiagnosticcontainer.h>
+
+namespace clang {
+namespace ast_matchers {
+namespace dynamic {
+class Diagnostics;
+}
+
+namespace internal {
+class DynTypedMatcher;
+}
+}
+
+class SourceManager;
+}
+
+namespace ClangBackEnd {
+
+class ClangQuery : public ClangTool
+{
+public:
+    ClangQuery(Utils::SmallString &&query={});
+
+    void setQuery(Utils::SmallString &&query);
+
+    void findLocations();
+
+    SourceRangesContainer takeSourceRanges();
+    std::vector<DynamicASTMatcherDiagnosticContainer> takeDiagnosticContainers();
+
+private:
+    void parseDiagnostics(const clang::ast_matchers::dynamic::Diagnostics &diagnostics);
+    void matchLocation(const llvm::Optional< clang::ast_matchers::internal::DynTypedMatcher> &optionalStartMatcher,
+                       std::unique_ptr<clang::ASTUnit> ast,
+                       std::vector<clang::SourceRange> &sourceRanges);
+
+private:
+    SourceRangesContainer sourceRangesContainer;
+    Utils::SmallString query;
+    std::vector<DynamicASTMatcherDiagnosticContainer> diagnosticContainers_;
+};
+
+} // namespace ClangBackEnd