Add empty clangcpp parser functionality

The new parser is advertised in the help
An option is added to the command line argument
A new loadcpp function is added to parse with clang
No code needing clang library is added yet.

Change-Id: Iee07fce319e6be13d3689077ab61c1e4e44b5fc2
Reviewed-by: Kai Koehne <kai.koehne@qt.io>

4 files changed, 124 insertions, 2 deletions

diff --git a/src/linguist/lupdate/cpp_clang.cpp b/src/linguist/lupdate/cpp_clang.cpp
new file mode 100644
index 000000000..198724f50
--- /dev/null
+++ b/src/linguist/lupdate/cpp_clang.cpp
@@ -0,0 +1,62 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Linguist of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "cpp_clang.h"
+
+#include <translator.h>
+
+QT_BEGIN_NAMESPACE
+
+void ClangCppParser::loadCPP(Translator &translator, const QStringList &filenames,
+    ConversionData &cd)
+{
+    // Going through the files to be parsed
+    std::vector<std::string> sources;
+    for (const QString &filename: filenames)
+       sources.push_back(filename.toStdString());
+
+    // The ClangTool is to be created and run from this function.
+
+    // First we'll need an OptionParser
+    // Then we'll create a ClangTool taking the OptionParser and the sources as argument
+
+    // The translator to store the information from the parsing of the files.
+    Translator *tor = new Translator();
+
+    // TODO: set up clang tool for parsing
+    qWarning("lupdate: Clang based C++ parser not implemented!");
+
+    // TODO: remove this printing at a later point
+    // Printing the translator (storage and manipulation of translation info from linguist module)
+    if (qEnvironmentVariableIsSet("QT_LUPDATE_CLANG_DEBUG"))
+        tor->dump();
+
+    for (const TranslatorMessage &msg: tor->messages())
+        translator.extend(msg, cd);
+
+}
+QT_END_NAMESPACE
diff --git a/src/linguist/lupdate/cpp_clang.h b/src/linguist/lupdate/cpp_clang.h
new file mode 100644
index 000000000..d4357f129
--- /dev/null
+++ b/src/linguist/lupdate/cpp_clang.h
@@ -0,0 +1,45 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Linguist of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef CLANG_CPP_H
+#define CLANG_CPP_H
+
+#include "lupdate.h"
+
+
+QT_BEGIN_NAMESPACE
+
+namespace ClangCppParser {
+   void loadCPP(Translator &translator, const QStringList &filenames,
+   ConversionData &cd);
+}
+
+QT_END_NAMESPACE
+
+
+#endif
diff --git a/src/linguist/lupdate/lupdate.pro b/src/linguist/lupdate/lupdate.pro
index e69703da2..615b41802 100644
--- a/src/linguist/lupdate/lupdate.pro
+++ b/src/linguist/lupdate/lupdate.pro
@@ -21,13 +21,15 @@ SOURCES += \
     \
     cpp.cpp \
     java.cpp \
-    ui.cpp
+    ui.cpp \
+    cpp_clang.cpp
 
 qtHaveModule(qmldevtools-private): SOURCES += qdeclarative.cpp
 
 HEADERS += \
     lupdate.h \
     cpp.h \
+    cpp_clang.h \
     ../shared/projectdescriptionreader.h \
     ../shared/qrcreader.h \
     ../shared/runqttool.h \
diff --git a/src/linguist/lupdate/main.cpp b/src/linguist/lupdate/main.cpp
index 712b95550..5ab3f59b9 100644
--- a/src/linguist/lupdate/main.cpp
+++ b/src/linguist/lupdate/main.cpp
@@ -28,6 +28,7 @@
 ****************************************************************************/
 
 #include "lupdate.h"
+#include "cpp_clang.h"
 
 #include <profileutils.h>
 #include <projectdescriptionreader.h>
@@ -47,6 +48,8 @@
 
 #include <iostream>
 
+bool useClangToParseCpp = false;
+
 // Can't have an array of QStaticStringData<N> for different N, so
 // use QString, which requires constructor calls. Doesn't matter
 // much, since this is in an app, not a lib:
@@ -275,6 +278,9 @@ static void printUsage()
         "           Specify the output file(s). This will override the TRANSLATIONS.\n"
         "    -version\n"
         "           Display the version of lupdate and exit.\n"
+        "    -clang-parser \n"
+        "           Use clang to parse cpp files. Otherwise a custom parser is used.\n"
+        "           Need a compile_commands.json for the files that needs to be parsed.\n"
         "    @lst-file\n"
         "           Read additional file names (one per line) or includepaths (one per\n"
         "           line, and prefixed with -I) from lst-file.\n"
@@ -513,7 +519,11 @@ static void processSources(Translator &fetchedTor,
         printErr(LU::tr("lupdate warning: Some files have been ignored due to missing qml/javascript support\n"));
 #endif
 
-    loadCPP(fetchedTor, sourceFilesCpp, cd);
+    if (useClangToParseCpp)
+        ClangCppParser::loadCPP(fetchedTor, sourceFilesCpp, cd);
+    else
+        loadCPP(fetchedTor, sourceFilesCpp, cd);
+
     if (!cd.error().isEmpty())
         printErr(cd.error());
 }
@@ -833,6 +843,9 @@ int main(int argc, char **argv)
                 includePath += args[i].mid(2);
             }
             continue;
+        } else if (arg == QLatin1String("-clang-parser")) {
+            useClangToParseCpp = true;
+            continue;
         } else if (arg.startsWith(QLatin1String("-")) && arg != QLatin1String("-")) {
             printErr(LU::tr("Unrecognized option '%1'.\n").arg(arg));
             return 1;