valgrind: code cosmetics

Change-Id: I695c7d40aeb0b0b1e6f8cc0856e5fa5d9d1ce2d1
Reviewed-on: http://codereview.qt.nokia.com/1600
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/valgrind/callgrind/callgrindcycledetection.cpp

@@ -0,0 +1,123 @@
+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2011 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+**
+** GNU Lesser General Public License Usage
+**
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this file.
+** Please review the following information to ensure the GNU Lesser General
+** Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** Other Usage
+**
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at info@qt.nokia.com.
+**
+**************************************************************************/
+
+#include "callgrindcycledetection.h"
+
+#include "callgrindfunction.h"
+#include "callgrindfunctioncall.h"
+#include "callgrindparsedata.h"
+#include "callgrindfunctioncycle.h"
+
+#include <utils/qtcassert.h>
+
+#include <QtCore/QDebug>
+
+namespace Valgrind {
+namespace Callgrind {
+namespace Internal {
+
+CycleDetection::CycleDetection(ParseData *data)
+    : m_data(data)
+    , m_depth(0)
+    , m_cycle(0)
+{
+}
+
+QVector<const Function *> CycleDetection::run(const QVector<const Function *> &input)
+{
+    foreach (const Function *function, input) {
+        Node *node = new Node;
+        node->function = function;
+        node->dfs = -1;
+        node->lowlink = -1;
+        m_nodes.insert(function, node);
+    }
+    foreach (Node *node, m_nodes) {
+        if (node->dfs == -1)
+            tarjan(node);
+    }
+    qDeleteAll(m_nodes);
+    return m_ret;
+}
+
+void CycleDetection::tarjan(Node *node)
+{
+    QTC_ASSERT(node->dfs == -1, return);
+    node->dfs = m_depth;
+    node->lowlink = m_depth;
+
+    m_depth++;
+    m_stack.push(node);
+
+    foreach (const FunctionCall *call, node->function->outgoingCalls())
+        tarjanForChildNode(node, m_nodes.value(call->callee()));
+
+    if (node->dfs == node->lowlink) {
+        QVector<const Function *> functions;
+        Node *n;
+        do {
+            n = m_stack.pop();
+            functions << n->function;
+        } while (n != node);
+
+        if (functions.size() == 1) {
+            // not a real cycle
+            m_ret.append(node->function);
+        } else {
+            // actual cycle
+            FunctionCycle *cycle = new FunctionCycle(m_data);
+            cycle->setFile(node->function->fileId());
+            m_cycle++;
+            qint64 id = -1;
+            m_data->addCompressedFunction(QString("cycle %1").arg(m_cycle), id);
+            cycle->setName(id);
+            cycle->setObject(node->function->objectId());
+            cycle->setFunctions(functions);
+            m_ret.append(cycle);
+        }
+    }
+}
+
+void CycleDetection::tarjanForChildNode(Node *node, Node *childNode)
+{
+    if (childNode->dfs == -1) {
+        tarjan(childNode);
+        if (childNode->lowlink < node->lowlink)
+            node->lowlink = childNode->lowlink;
+    } else if (childNode->dfs < node->lowlink && m_stack.contains(childNode)) {
+        node->lowlink = childNode->dfs;
+    }
+}
+
+} // namespace Internal
+} // namespace Callgrind
+} // namespace Valgrind