shiboken6: Add a dot view

shiboken uses directed graphs in a few places (class dependencies,
overload order). Add a helper function to show the graphs
for debugging purposes.

Task-number: PYSIDE-1660
Change-Id: Ie760954ddf8cb7aa31db2c79854063159658ed4b
Reviewed-by: Christian Tismer <tismer@stackless.com>

6 files changed, 153 insertions, 1 deletions

diff --git a/sources/shiboken6/ApiExtractor/CMakeLists.txt b/sources/shiboken6/ApiExtractor/CMakeLists.txt
index 040d85f54..8d2d194ab 100644
--- a/sources/shiboken6/ApiExtractor/CMakeLists.txt
+++ b/sources/shiboken6/ApiExtractor/CMakeLists.txt
@@ -18,6 +18,7 @@ abstractmetalang.cpp
 codesniphelpers.cpp
 conditionalstreamreader.cpp
 documentation.cpp
+dotview.cpp
 enclosingclassmixin.cpp
 fileout.cpp
 messages.cpp
diff --git a/sources/shiboken6/ApiExtractor/dotview.cpp b/sources/shiboken6/ApiExtractor/dotview.cpp
new file mode 100644
index 000000000..0ead28f68
--- /dev/null
+++ b/sources/shiboken6/ApiExtractor/dotview.cpp
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt for Python.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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 "dotview.h"
+
+#include <QtCore/QDebug>
+#include <QtCore/QDir>
+#include <QtCore/QFile>
+#include <QtCore/QProcess>
+#include <QtCore/QTemporaryFile>
+
+bool showDotGraph(const QString &name, const QString &graph)
+{
+    const QString imageType = u"jpg"_qs;
+
+    // Write out the graph to a temporary file
+    QTemporaryFile dotFile(QDir::tempPath() + u'/' + name + u"_XXXXXX.dot"_qs);
+    if (!dotFile.open()) {
+        qWarning("Cannot open temporary file: %s", qPrintable(dotFile.errorString()));
+        return false;
+    }
+    const QString tempDotFile = dotFile.fileName();
+    dotFile.write(graph.toUtf8());
+    dotFile.close();
+
+    // Convert to image using "dot"
+    const QString imageFile = tempDotFile.left(tempDotFile.size() - 3) + imageType;
+    QProcess process;
+    process.start(u"dot"_qs, {u"-T"_qs + imageType, u"-o"_qs + imageFile, tempDotFile});
+    if (!process.waitForStarted() || !process.waitForFinished()) {
+        qWarning("Image conversion failed: %s", qPrintable(process.errorString()));
+        return false;
+    }
+    if (process.exitStatus() != QProcess::NormalExit || process.exitCode() != 0) {
+        qWarning("Image conversion failed (%d): %s",
+                 process.exitCode(),
+                 process.readAllStandardError().constData());
+        return false;
+    }
+
+    // Launch image. Should use QDesktopServices::openUrl(),
+    // but we don't link against QtGui
+#ifdef Q_OS_UNIX
+    const QString imageViewer = u"gwenview"_qs;
+#else
+    const QString imageViewer = u"mspaint"_qs;
+#endif
+    if (!QProcess::startDetached(imageViewer, {imageFile})) {
+        qWarning("Failed to launch viewer: %s", qPrintable(imageViewer));
+        return false;
+    }
+    qInfo().noquote().nospace() << "Viewing: "
+        << QDir::toNativeSeparators(tempDotFile)
+        << ' ' << QDir::toNativeSeparators(imageFile);
+    return true;
+}
diff --git a/sources/shiboken6/ApiExtractor/dotview.h b/sources/shiboken6/ApiExtractor/dotview.h
new file mode 100644
index 000000000..462cc2b75
--- /dev/null
+++ b/sources/shiboken6/ApiExtractor/dotview.h
@@ -0,0 +1,39 @@
+/****************************************************************************
+**
+** Copyright (C) 2021 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt for Python.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** 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 DOTVIEW_H
+#define DOTVIEW_H
+
+#include <QtCore/QString>
+
+/// Show a dot digraph in an image viewer
+/// \param name base name for files
+/// \param graph graph
+bool showDotGraph(const QString &name, const QString &graph);
+
+#endif // DOTVIEW_H
diff --git a/sources/shiboken6/ApiExtractor/graph.h b/sources/shiboken6/ApiExtractor/graph.h
index 0961f85af..26aed4328 100644
--- a/sources/shiboken6/ApiExtractor/graph.h
+++ b/sources/shiboken6/ApiExtractor/graph.h
@@ -29,6 +29,8 @@
 #ifndef GRAPH_H
 #define GRAPH_H
 
+#include "dotview.h"
+
 #include <QtCore/QDebug>
 #include <QtCore/QFile>
 #include <QtCore/QHash>
@@ -98,6 +100,10 @@ public:
     /// \param f function returning the name of a node
     template <class NameFunction>
     bool dumpDot(const QString& fileName, NameFunction f) const;
+    template <class NameFunction>
+    void formatDot(QTextStream &str, NameFunction f) const;
+    template <class NameFunction>
+    bool showGraph(const QString &name, NameFunction f) const;
 
     void format(QDebug &debug) const;
 
@@ -251,6 +257,15 @@ bool Graph<Node>::dumpDot(const QString& fileName,
     if (!output.open(QIODevice::WriteOnly))
         return false;
     QTextStream s(&output);
+    formatDot(s, nameFunction);
+    return true;
+}
+
+template <class Node>
+template <class NameFunction>
+void Graph<Node>::formatDot(QTextStream &s,
+                            NameFunction nameFunction) const
+{
     s << "digraph D {\n";
     for (const auto &nodeEntry : m_nodeEntries) {
         if (!nodeEntry.targets.isEmpty()) {
@@ -260,7 +275,16 @@ bool Graph<Node>::dumpDot(const QString& fileName,
         }
     }
     s << "}\n";
-    return true;
+}
+
+template <class Node>
+template <class NameFunction>
+bool Graph<Node>::showGraph(const QString &name, NameFunction f) const
+{
+    QString graph;
+    QTextStream s(&graph);
+    formatDot(s, f);
+    return showDotGraph(name, graph);
 }
 
 template <class Node>
diff --git a/sources/shiboken6/generator/shiboken/overloaddata.cpp b/sources/shiboken6/generator/shiboken/overloaddata.cpp
index 137a37aeb..a359e8024 100644
--- a/sources/shiboken6/generator/shiboken/overloaddata.cpp
+++ b/sources/shiboken6/generator/shiboken/overloaddata.cpp
@@ -29,6 +29,7 @@
 #include <abstractmetafunction.h>
 #include <apiextractorresult.h>
 #include <abstractmetalang.h>
+#include <dotview.h>
 #include <reporthandler.h>
 #include <typesystem.h>
 #include <graph.h>
@@ -787,6 +788,11 @@ QString OverloadData::dumpGraph() const
     return result;
 }
 
+bool OverloadData::showGraph() const
+{
+    return showDotGraph(referenceFunction()->name(), dumpGraph());
+}
+
 static inline QString toHtml(QString s)
 {
     s.replace(QLatin1Char('<'), QLatin1String("&lt;"));
diff --git a/sources/shiboken6/generator/shiboken/overloaddata.h b/sources/shiboken6/generator/shiboken/overloaddata.h
index fb367b259..0271fd3d0 100644
--- a/sources/shiboken6/generator/shiboken/overloaddata.h
+++ b/sources/shiboken6/generator/shiboken/overloaddata.h
@@ -179,6 +179,7 @@ public:
 
     void dumpGraph(const QString &filename) const;
     QString dumpGraph() const;
+    bool showGraph() const;
 
     /// Returns true if a list of arguments is used (METH_VARARGS)
     bool pythonFunctionWrapperUsesListOfArguments() const;