Clang: Extract TranslationUnitCore and (re)parse explicitly

Extract TranslationUnitCore, which is the API for the high-level
operations we need. TranslationUnit does not call any clang_* functions
anymore, except the one needed for disposing the CXTranslationUnit - for
now, we keep TranslationUnit the owner of TranslationUnitCore.

TranslationUnitCore will be passed on to the worker threads.

With this, the current "TranslationUnit" looses its meaning. We will
rename it to "Document" in a follow-up change.

                            ***

TranslationUnit::cxTranslationUnit does not implicitly
creates/parses/reparses anymore. We use more verbose update operations
now.

The test ClangIpcServer.GetCodeCompletionDependingOnArgumets fails now
because of this - CodeCompleter::completeHelper() does not recreate the
translation unit anymore, thus working on the old data.

This will be addressed in a follow-up change.

Change-Id: I6213d6f1609cd3c9a54666c84cb8b623b2fefe1c
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

src/tools/clangbackend/ipcsource/clangtranslationunitcore.h

@@ -0,0 +1,102 @@
+/****************************************************************************
+**
+** 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 <clangbackendipc/codecompletion.h>
+
+#include <utf8string.h>
+
+#include <clang-c/Index.h>
+
+class Utf8String;
+
+namespace ClangBackEnd {
+
+class Cursor;
+class DiagnosticContainer;
+class DiagnosticSet;
+class HighlightingMarkContainer;
+class HighlightingMarks;
+class SkippedSourceRanges;
+class SourceLocation;
+class SourceRange;
+class SourceRangeContainer;
+class TranslationUnitUpdateInput;
+class TranslationUnitUpdateResult;
+class UnsavedFiles;
+
+class TranslationUnitCore
+{
+public:
+    struct CodeCompletionResult {
+        CodeCompletions completions;
+        CompletionCorrection correction;
+    };
+
+public:
+    TranslationUnitCore(const Utf8String &filePath,
+                        CXIndex &cxIndex,
+                        CXTranslationUnit &cxTranslationUnit);
+
+    bool isNull() const;
+
+    Utf8String filePath() const;
+    CXIndex &cxIndex() const;
+    CXTranslationUnit &cxTranslationUnit() const;
+
+    TranslationUnitUpdateResult update(const TranslationUnitUpdateInput &parseInput) const;
+    TranslationUnitUpdateResult parse(const TranslationUnitUpdateInput &parseInput) const;
+    TranslationUnitUpdateResult reparse(const TranslationUnitUpdateInput &parseInput) const;
+
+    CodeCompletionResult complete(UnsavedFiles &unsavedFiles, uint line, uint column) const;
+
+    void extractDocumentAnnotations(QVector<DiagnosticContainer> &diagnostics,
+                                    QVector<HighlightingMarkContainer> &highlightingMarks,
+                                    QVector<SourceRangeContainer> &skippedSourceRanges) const;
+
+    DiagnosticSet diagnostics() const;
+    QVector<DiagnosticContainer> mainFileDiagnostics() const;
+
+    SourceLocation sourceLocationAt(uint line, uint column) const;
+    SourceLocation sourceLocationAt(const Utf8String &filePath, uint line, uint column) const;
+    SourceRange sourceRange(uint fromLine, uint fromColumn, uint toLine, uint toColumn) const;
+
+    Cursor cursorAt(uint line, uint column) const;
+    Cursor cursorAt(const Utf8String &filePath, uint line, uint column) const;
+    Cursor cursor() const;
+
+    HighlightingMarks highlightingMarks() const;
+    HighlightingMarks highlightingMarksInRange(const SourceRange &range) const;
+
+    SkippedSourceRanges skippedSourceRanges() const;
+
+private:
+    const Utf8String m_filePath;
+    CXIndex &m_cxIndex;
+    CXTranslationUnit &m_cxTranslationUnit;
+};
+
+} // namespace ClangBackEnd