Factored readRegistryKey implementation out of qmake

This function is now implemented with its own header and source
files, rather than being embedded within the MSVC qmake generator.

The motivation for this is to allow code to be shared between
qmake and configure, both of which query the registry when built for
Windows.

Reviewed-by: Miikka Heikkinen
(cherry picked from commit 5254184c07b4da800e29000a251ed2a026bd2be5)

Conflicts:

	qmake/Makefile.unix

2 files changed, 225 insertions, 0 deletions

diff --git a/tools/shared/windows/registry.cpp b/tools/shared/windows/registry.cpp
new file mode 100644
index 0000000..d342d78
--- /dev/null
+++ b/tools/shared/windows/registry.cpp
@@ -0,0 +1,161 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the qmake application of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtCore/qstringlist.h>
+#include "registry.h"
+
+/*!
+  Returns the path part of a registry key.
+  e.g.
+      For a key
+          "Software\\Microsoft\\VisualStudio\\8.0\\Setup\\VC\\ProductDir"
+      it returns
+          "Software\\Microsoft\\VisualStudio\\8.0\\Setup\\VC\\"
+*/
+static QString keyPath(const QString &rKey)
+{
+    int idx = rKey.lastIndexOf(QLatin1Char('\\'));
+    if (idx == -1)
+        return QString();
+    return rKey.left(idx + 1);
+}
+
+/*!
+  Returns the name part of a registry key.
+  e.g.
+      For a key
+          "Software\\Microsoft\\VisualStudio\\8.0\\Setup\\VC\\ProductDir"
+      it returns
+          "ProductDir"
+*/
+static QString keyName(const QString &rKey)
+{
+    int idx = rKey.lastIndexOf(QLatin1Char('\\'));
+    if (idx == -1)
+        return rKey;
+
+    QString res(rKey.mid(idx + 1));
+    if (res == "Default" || res == ".")
+        res = "";
+    return res;
+}
+
+QString readRegistryKey(HKEY parentHandle, const QString &rSubkey)
+{
+    QString result;
+
+#ifdef Q_OS_WIN32
+    QString rSubkeyName = keyName(rSubkey);
+    QString rSubkeyPath = keyPath(rSubkey);
+
+    HKEY handle = 0;
+    LONG res = RegOpenKeyEx(parentHandle, (wchar_t*)rSubkeyPath.utf16(), 0, KEY_READ, &handle);
+
+    if (res != ERROR_SUCCESS)
+        return QString();
+
+    // get the size and type of the value
+    DWORD dataType;
+    DWORD dataSize;
+    res = RegQueryValueEx(handle, (wchar_t*)rSubkeyName.utf16(), 0, &dataType, 0, &dataSize);
+    if (res != ERROR_SUCCESS) {
+        RegCloseKey(handle);
+        return QString();
+    }
+
+    // get the value
+    QByteArray data(dataSize, 0);
+    res = RegQueryValueEx(handle, (wchar_t*)rSubkeyName.utf16(), 0, 0,
+                          reinterpret_cast<unsigned char*>(data.data()), &dataSize);
+    if (res != ERROR_SUCCESS) {
+        RegCloseKey(handle);
+        return QString();
+    }
+
+    switch (dataType) {
+        case REG_EXPAND_SZ:
+        case REG_SZ: {
+            result = QString::fromWCharArray(((const wchar_t *)data.constData()));
+            break;
+        }
+
+        case REG_MULTI_SZ: {
+            QStringList l;
+            int i = 0;
+            for (;;) {
+                QString s = QString::fromWCharArray((const wchar_t *)data.constData() + i);
+                i += s.length() + 1;
+
+                if (s.isEmpty())
+                    break;
+                l.append(s);
+            }
+            result = l.join(", ");
+            break;
+        }
+
+        case REG_NONE:
+        case REG_BINARY: {
+            result = QString::fromWCharArray((const wchar_t *)data.constData(), data.size() / 2);
+            break;
+        }
+
+        case REG_DWORD_BIG_ENDIAN:
+        case REG_DWORD: {
+            Q_ASSERT(data.size() == sizeof(int));
+            int i;
+            memcpy((char*)&i, data.constData(), sizeof(int));
+            result = QString::number(i);
+            break;
+        }
+
+        default:
+            qWarning("QSettings: unknown data %d type in windows registry", dataType);
+            break;
+    }
+
+    RegCloseKey(handle);
+#endif
+
+    return result;
+}
+
+
diff --git a/tools/shared/windows/registry.h b/tools/shared/windows/registry.h
new file mode 100644
index 0000000..3896527
--- /dev/null
+++ b/tools/shared/windows/registry.h
@@ -0,0 +1,64 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the qmake application of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef WINDOWS_REGISTRY_H
+#define WINDOWS_REGISTRY_H
+
+#include <QtCore/qglobal.h>
+
+#ifdef Q_OS_WIN32
+   #include <QtCore/qt_windows.h>
+#else
+    typedef void* HKEY;
+#endif
+
+#include <QtCore/qstring.h>
+
+/**
+ * Read a value from the Windows registry.
+ *
+ * If the key is not found, or the registry cannot be accessed (for example
+ * if this code is compiled for a platform other than Windows), a null
+ * string is returned.
+ */
+QString readRegistryKey(HKEY parentHandle, const QString &rSubkey);
+
+#endif // WINDOWS_REGISTRY_H