Factored epocRoot implementation out of qmake

This function is now implemented in its own source file, rather
than being embedded within the Symbian qmake generator.

The motivation for this is to allow code to be shared between
qmake and configure - the latter needs to determine the epoc
root path in order to perform feature detection on Symbian SDKs.

Reviewed-by: Miikka Heikkinen
(cherry picked from commit 6ebcf2c24b43fdc1d6da50e9d7ec9dd63dd507d7)

13 files changed, 292 insertions, 106 deletions

diff --git a/qmake/Makefile.unix b/qmake/Makefile.unix
index 0d6c117..94b34b7 100644
--- a/qmake/Makefile.unix
+++ b/qmake/Makefile.unix
@@ -11,7 +11,8 @@ OBJS=project.o property.o main.o makefile.o unixmake2.o unixmake.o  \
      meta.o makefiledeps.o metamakefile.o xmloutput.o pbuilder_pbx.o \
      borland_bmake.o msvc_vcproj.o msvc_nmake.o msvc_objectmodel.o \
      symmake.o initprojectdeploy_symbian.o symmake_abld.o symmake_sbsv2.o \
-     registry.o
+     registry.o \
+     epocroot.o
 
 #qt code
 QOBJS=qtextcodec.o qutfcodec.o qstring.o qtextstream.o qiodevice.o qmalloc.o qglobal.o \
@@ -22,6 +23,7 @@ QOBJS=qtextcodec.o qutfcodec.o qstring.o qtextstream.o qiodevice.o qmalloc.o qgl
       qmap.o qmetatype.o qsettings.o qlibraryinfo.o qvariant.o qvsnprintf.o \
       qlocale.o qlinkedlist.o qurl.o qnumeric.o qcryptographichash.o qxmlstream.o qxmlutils.o \
       registry.o \
+      epocroot.o \
       $(QTOBJS)
 
 
@@ -35,6 +37,7 @@ DEPEND_SRC=project.cpp property.cpp meta.cpp main.cpp generators/makefile.cpp ge
 	   generators/win32/msvc_objectmodel.cpp generators/win32/msvc_nmake.cpp generators/win32/borland_bmake.cpp \
 	   generators/symbian/symmake.cpp generators/symbian/initprojectdeploy_symbian.cpp \
 	   $(SOURCE_PATH)/tools/shared/windows/registry.cpp \
+	   $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp \
 	   generators/symbian/symmake_abld.cpp generators/symbian/symmake_sbsv2.cpp \
 	   $(SOURCE_PATH)/src/corelib/codecs/qtextcodec.cpp $(SOURCE_PATH)/src/corelib/codecs/qutfcodec.cpp \
 	   $(SOURCE_PATH)/src/corelib/tools/qstring.cpp $(SOURCE_PATH)/src/corelib/io/qfile.cpp \
@@ -285,6 +288,9 @@ initprojectdeploy_symbian.o: generators/symbian/initprojectdeploy_symbian.cpp
 registry.o: $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 	$(CXX) -c -o $@ $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 
+epocroot.o: $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+	$(CXX) -c -o $@ $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+
 projectgenerator.o: generators/projectgenerator.cpp
 	$(CXX) -c -o $@ $(CXXFLAGS) generators/projectgenerator.cpp
 
@@ -293,6 +299,7 @@ qxmlstream.o: $(SOURCE_PATH)/src/corelib/xml/qxmlstream.cpp
 
 qxmlutils.o: $(SOURCE_PATH)/src/corelib/xml/qxmlutils.cpp
 	$(CXX) -c -o $@ $(CXXFLAGS) $(SOURCE_PATH)/src/corelib/xml/qxmlutils.cpp
+
 #default rules
 .cpp.o:
 	$(CXX) -c -o $@ $(CXXFLAGS) $<
diff --git a/qmake/Makefile.win32 b/qmake/Makefile.win32
index bbc37c1..a598350 100644
--- a/qmake/Makefile.win32
+++ b/qmake/Makefile.win32
@@ -78,6 +78,7 @@ OBJS        = project.obj main.obj makefile.obj unixmake.obj unixmake2.obj mingw
               borland_bmake.obj msvc_nmake.obj msvc_vcproj.obj \
               msvc_objectmodel.obj symmake.obj initprojectdeploy_symbian.obj \
               registry.obj \
+              epocroot.obj \
               symmake_abld.obj symmake_sbsv2.obj
 
 !IFDEF QMAKE_OPENSOURCE_EDITION
@@ -201,6 +202,7 @@ clean::
 	-del symmake_sbsv2.obj
 	-del initprojectdeploy_symbian.obj
 	-del registry.obj
+	-del epocroot.obj
 	-del pbuilder_pbx.obj
 	-del qxmlstream.obj
 	-del qxmlutils.obj
@@ -400,6 +402,9 @@ initprojectdeploy_symbian.obj: $(SOURCE_PATH)/qmake/generators/symbian/initproje
 registry.obj: $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 
+epocroot.obj: $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+
 md5.obj: $(SOURCE_PATH)\src\3rdparty\md5\md5.cpp
 	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)\src\3rdparty\md5\md5.cpp
 
diff --git a/qmake/Makefile.win32-g++ b/qmake/Makefile.win32-g++
index 0b47905..d4d6e0e 100644
--- a/qmake/Makefile.win32-g++
+++ b/qmake/Makefile.win32-g++
@@ -40,6 +40,7 @@ OBJS        = project.o main.o makefile.o unixmake.o unixmake2.o mingw_make.o \
               borland_bmake.o msvc_nmake.o msvc_vcproj.o \
               msvc_objectmodel.o symmake.o initprojectdeploy_symbian.o \
               registry.o \
+              epocroot.o \
               symmake_abld.o symmake_sbsv2.o
 
 ifdef QMAKE_OPENSOURCE_EDITION
@@ -280,6 +281,9 @@ initprojectdeploy_symbian.o: $(SOURCE_PATH)/qmake/generators/symbian/initproject
 registry.o: $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 
+epocroot.o: $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+
 project.o: $(SOURCE_PATH)/qmake/project.cpp $(SOURCE_PATH)/qmake/project.h $(SOURCE_PATH)/qmake/option.h
 	$(CXX) $(CXXFLAGS) project.cpp
 
diff --git a/qmake/Makefile.win32-g++-sh b/qmake/Makefile.win32-g++-sh
index 0772aff..5061089 100644
--- a/qmake/Makefile.win32-g++-sh
+++ b/qmake/Makefile.win32-g++-sh
@@ -40,6 +40,7 @@ OBJS        = project.o main.o makefile.o unixmake.o unixmake2.o mingw_make.o \
               borland_bmake.o msvc_nmake.o msvc_vcproj.o \
               msvc_objectmodel.o symmake.o initprojectdeploy_symbian.o \
               registry.o \
+              epocroot.o \
               symmake_abld.o symmake_sbsv2.o
 
 ifdef QMAKE_OPENSOURCE_EDITION
@@ -279,6 +280,9 @@ initprojectdeploy_symbian.o: $(SOURCE_PATH)/qmake/generators/symbian/initproject
 registry.o: $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/windows/registry.cpp
 
+epocroot.o: $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+	$(CXX) $(CXXFLAGS) $(SOURCE_PATH)/tools/shared/symbian/epocroot.cpp
+
 project.o: $(SOURCE_PATH)/qmake/project.cpp $(SOURCE_PATH)/qmake/project.h $(SOURCE_PATH)/qmake/option.h
 	$(CXX) $(CXXFLAGS) project.cpp
 
diff --git a/qmake/generators/symbian/initprojectdeploy_symbian.cpp b/qmake/generators/symbian/initprojectdeploy_symbian.cpp
index 7279a4c..0d50112 100644
--- a/qmake/generators/symbian/initprojectdeploy_symbian.cpp
+++ b/qmake/generators/symbian/initprojectdeploy_symbian.cpp
@@ -46,105 +46,15 @@
 #include <qsettings.h>
 #include <qdebug.h>
 
+// Included from tools/shared
+#include <symbian/epocroot.h>
+
 #define SYSBIN_DIR "\\sys\\bin"
 
 #define SUFFIX_DLL "dll"
 #define SUFFIX_EXE "exe"
 #define SUFFIX_QTPLUGIN "qtplugin"
 
-static void fixEpocRootStr(QString& path)
-{
-    path.replace("\\", "/");
-
-    if (path.size() > 1 && path[1] == QChar(':')) {
-        path = path.mid(2);
-    }
-
-    if (!path.size() || path[path.size()-1] != QChar('/')) {
-        path += QChar('/');
-    }
-}
-
-#define SYMBIAN_SDKS_KEY "HKEY_LOCAL_MACHINE\\Software\\Symbian\\EPOC SDKs"
-
-static QString epocRootStr;
-
-QString epocRoot()
-{
-    if (!epocRootStr.isEmpty()) {
-        return epocRootStr;
-    }
-
-    // First, check the env variable
-    epocRootStr = qgetenv("EPOCROOT");
-
-    if (epocRootStr.isEmpty()) {
-        // No EPOCROOT set, check the default device
-        // First check EPOCDEVICE env variable
-        QString defaultDevice = qgetenv("EPOCDEVICE");
-
-        // Check the windows registry via QSettings for devices.xml path
-        QSettings settings(SYMBIAN_SDKS_KEY, QSettings::NativeFormat);
-        QString devicesXmlPath = settings.value("CommonPath").toString();
-
-        if (!devicesXmlPath.isEmpty()) {
-            // Parse xml for correct device
-            devicesXmlPath += "/devices.xml";
-            QFile devicesFile(devicesXmlPath);
-            if (devicesFile.open(QIODevice::ReadOnly)) {
-                QXmlStreamReader xml(&devicesFile);
-                while (!xml.atEnd()) {
-                    xml.readNext();
-                    if (xml.isStartElement() && xml.name() == "devices") {
-                        if (xml.attributes().value("version") == "1.0") {
-                            // Look for correct device
-                            while (!(xml.isEndElement() && xml.name() == "devices") && !xml.atEnd()) {
-                                xml.readNext();
-                                if (xml.isStartElement() && xml.name() == "device") {
-                                    if ((defaultDevice.isEmpty() && xml.attributes().value("default") == "yes") ||
-                                        (!defaultDevice.isEmpty() && (xml.attributes().value("id").toString() + QString(":") + xml.attributes().value("name").toString()) == defaultDevice)) {
-                                        // Found the correct device
-                                        while (!(xml.isEndElement() && xml.name() == "device") && !xml.atEnd()) {
-                                            xml.readNext();
-                                            if (xml.isStartElement() && xml.name() == "epocroot") {
-                                                epocRootStr = xml.readElementText();
-                                                fixEpocRootStr(epocRootStr);
-                                                return epocRootStr;
-                                            }
-                                        }
-                                        xml.raiseError("No epocroot element found");
-                                    }
-                                }
-                            }
-                        } else {
-                            xml.raiseError("Invalid 'devices' element version");
-                        }
-                    }
-                }
-                if (xml.hasError()) {
-                    fprintf(stderr, "ERROR: \"%s\" when parsing devices.xml\n", qPrintable(xml.errorString()));
-                }
-            } else {
-                fprintf(stderr, "Could not open devices.xml (%s)\n", qPrintable(devicesXmlPath));
-            }
-        } else {
-            fprintf(stderr, "Could not retrieve " SYMBIAN_SDKS_KEY " setting\n");
-        }
-
-        fprintf(stderr, "Failed to determine epoc root.\n");
-        if (!defaultDevice.isEmpty())
-            fprintf(stderr, "The device indicated by EPOCDEVICE environment variable (%s) could not be found.\n", qPrintable(defaultDevice));
-        fprintf(stderr, "Either set EPOCROOT or EPOCDEVICE environment variable to a valid value, or provide a default Symbian device.\n");
-
-        // No valid device found; set epocroot to "/"
-        epocRootStr = QLatin1String("/");
-    }
-
-    fixEpocRootStr(epocRootStr);
-    return epocRootStr;
-}
-
-
 static bool isPlugin(const QFileInfo& info, const QString& devicePath)
 {
     // Libraries are plugins if deployment path is something else than
diff --git a/qmake/generators/symbian/initprojectdeploy_symbian.h b/qmake/generators/symbian/initprojectdeploy_symbian.h
index e23e6a9..b409225 100644
--- a/qmake/generators/symbian/initprojectdeploy_symbian.h
+++ b/qmake/generators/symbian/initprojectdeploy_symbian.h
@@ -50,8 +50,6 @@
 #include <qfile.h>
 #include <stdlib.h>
 
-#include "epocroot.h"
-
 #define PLUGIN_STUB_DIR "qmakepluginstubs"
 
 struct CopyItem
diff --git a/qmake/generators/symbian/symmake.cpp b/qmake/generators/symbian/symmake.cpp
index 6854084..ac4bca3 100644
--- a/qmake/generators/symbian/symmake.cpp
+++ b/qmake/generators/symbian/symmake.cpp
@@ -49,6 +49,9 @@
 #include <stdlib.h>
 #include <qdebug.h>
 
+// Included from tools/shared
+#include <symbian/epocroot.h>
+
 #define RESOURCE_DIRECTORY_MMP "/resource/apps"
 #define RESOURCE_DIRECTORY_RESOURCE "\\\\resource\\\\apps\\\\"
 #define REGISTRATION_RESOURCE_DIRECTORY_HW "/private/10003a3f/import/apps"
diff --git a/qmake/generators/symbian/symmake_abld.cpp b/qmake/generators/symbian/symmake_abld.cpp
index 9b7ae3e..81165f5 100644
--- a/qmake/generators/symbian/symmake_abld.cpp
+++ b/qmake/generators/symbian/symmake_abld.cpp
@@ -48,6 +48,9 @@
 #include <qdatetime.h>
 #include <qdebug.h>
 
+// Included from tools/shared
+#include <symbian/epocroot.h>
+
 #define DO_NOTHING_TARGET "do_nothing"
 #define CREATE_TEMPS_TARGET "create_temps"
 #define EXTENSION_CLEAN "extension_clean"
diff --git a/qmake/generators/symbian/symmake_sbsv2.cpp b/qmake/generators/symbian/symmake_sbsv2.cpp
index f610181..4366f0e 100644
--- a/qmake/generators/symbian/symmake_sbsv2.cpp
+++ b/qmake/generators/symbian/symmake_sbsv2.cpp
@@ -48,6 +48,9 @@
 #include <qdatetime.h>
 #include <qdebug.h>
 
+// Included from tools/shared
+#include <symbian/epocroot.h>
+
 SymbianSbsv2MakefileGenerator::SymbianSbsv2MakefileGenerator() : SymbianMakefileGenerator() { }
 SymbianSbsv2MakefileGenerator::~SymbianSbsv2MakefileGenerator() { }
 
diff --git a/qmake/project.cpp b/qmake/project.cpp
index 8871152..4193163 100644
--- a/qmake/project.cpp
+++ b/qmake/project.cpp
@@ -44,8 +44,6 @@
 #include "option.h"
 #include "cachekeys.h"
 
-#include "epocroot.h"
-
 #include <qdatetime.h>
 #include <qfile.h>
 #include <qfileinfo.h>
@@ -64,6 +62,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+// Included from tools/shared
+#include <symbian/epocroot.h>
+
 #ifdef Q_OS_WIN32
 #define QT_POPEN _popen
 #define QT_PCLOSE _pclose
diff --git a/qmake/qmake.pri b/qmake/qmake.pri
index 187232f..0821f00 100644
--- a/qmake/qmake.pri
+++ b/qmake/qmake.pri
@@ -18,7 +18,8 @@ SOURCES += project.cpp property.cpp main.cpp generators/makefile.cpp \
            generators/symbian/symmake_abld.cpp \
            generators/symbian/symmake_sbsv2.cpp \
            generators/symbian/initprojectdeploy_symbian.cpp \
-           windows/registry.cpp
+           windows/registry.cpp \
+           symbian/epocroot.cpp
 
 HEADERS += project.h property.h generators/makefile.h \
            generators/unix/unixmake.h meta.h option.h cachekeys.h \
@@ -31,7 +32,8 @@ HEADERS += project.h property.h generators/makefile.h \
            generators/symbian/symmake_abld.h \
            generators/symbian/symmake_sbsv2.h \
            generators/symbian/initprojectdeploy_symbian.h \
-           windows/registry.h
+           windows/registry.h \
+           symbian/epocroot.h
 
 contains(QT_EDITION, OpenSource) {
    DEFINES += QMAKE_OPENSOURCE_EDITION
diff --git a/tools/shared/symbian/epocroot.cpp b/tools/shared/symbian/epocroot.cpp
new file mode 100644
index 0000000..071477d
--- /dev/null
+++ b/tools/shared/symbian/epocroot.cpp
@@ -0,0 +1,230 @@
+/****************************************************************************
+**
+** 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 <iostream>
+
+#include <QtCore/qdir.h>
+#include <QtCore/qxmlstream.h>
+
+#include "epocroot.h"
+#include "../windows/registry.h"
+
+// Registry key under which the location of the Symbian devices.xml file is
+// stored.
+// Note that, on 64-bit machines, this key is located under the 32-bit
+// compatibility key:
+//     HKEY_LOCAL_MACHINE\Software\Wow6432Node
+#define SYMBIAN_SDKS_REG_SUBKEY "Software\\Symbian\\EPOC SDKs\\CommonPath"
+
+#ifdef Q_OS_WIN32
+#   define SYMBIAN_SDKS_REG_HANDLE HKEY_LOCAL_MACHINE
+#else
+#   define SYMBIAN_SDKS_REG_HANDLE 0
+#endif
+
+// Value which is populated and returned by the epocRoot() function.
+// Stored as a static value in order to avoid unnecessary re-evaluation.
+static QString epocRootValue;
+
+#ifdef QT_BUILD_QMAKE
+std::ostream &operator<<(std::ostream &s, const QString &val) {
+    s << val.toLocal8Bit().data();
+    return s;
+}
+#else
+// Operator implemented in configureapp.cpp
+std::ostream &operator<<(std::ostream &s, const QString &val);
+#endif
+
+QString getDevicesXmlPath()
+    {
+    // Note that the following call will return a null string on platforms other
+    // than Windows.  If support is required on other platforms for devices.xml,
+    // an alternative mechanism for retrieving the location of this file will
+    // be required.
+    return readRegistryKey(SYMBIAN_SDKS_REG_HANDLE, SYMBIAN_SDKS_REG_SUBKEY);
+    }
+
+/**
+ * Checks whether epocRootValue points to an existent directory.
+ * If not, epocRootValue is set to an empty string and an error message is printed.
+ */
+void checkEpocRootExists(const QString &source)
+{
+    if (!epocRootValue.isEmpty()) {
+        QDir dir(epocRootValue);
+        if (!dir.exists()) {
+            std::cerr << "Warning: " << source << " is set to an invalid path: " << epocRootValue << std::endl;
+            epocRootValue = QString();
+        }
+    }
+}
+
+/**
+ * Translate path from Windows to Qt format.
+ */
+static void fixEpocRoot(QString &path)
+{
+    path.replace("\\", "/");
+
+    if (path.size() > 1 && path[1] == QChar(':')) {
+        path = path.mid(2);
+    }
+
+    if (!path.size() || path[path.size()-1] != QChar('/')) {
+        path += QChar('/');
+    }
+}
+
+/**
+ * Determine the epoc root for the currently active SDK.
+ */
+QString epocRoot()
+{
+    if (epocRootValue.isEmpty()) {
+        // 1. If environment variable EPOCROOT is set and points to an existent
+        //    directory, this is returned.
+        epocRootValue = qgetenv("EPOCROOT");
+        checkEpocRootExists("EPOCROOT");
+
+        if (epocRootValue.isEmpty()) {
+            // 2. The location of devices.xml is specified by a registry key.  If this
+            //    file exists, it is parsed.
+            QString devicesXmlPath = getDevicesXmlPath();
+            if (devicesXmlPath.isEmpty()) {
+                std::cerr << "Error: Symbian SDK registry key not found" << std::endl;
+            } else {
+                devicesXmlPath += "/devices.xml";
+                QFile devicesFile(devicesXmlPath);
+                if (devicesFile.open(QIODevice::ReadOnly)) {
+
+                    // 3. If the EPOCDEVICE environment variable is set and a corresponding
+                    //    entry is found in devices.xml, and its epocroot value points to an
+                    //    existent directory, it is returned.
+                    // 4. If a device element marked as default is found in devices.xml and its
+                    //    epocroot value points to an existent directory, this is returned.
+
+                    const QString epocDeviceValue = qgetenv("EPOCDEVICE");
+                    bool epocDeviceFound = false;
+
+                    QXmlStreamReader xml(&devicesFile);
+                    while (!xml.atEnd()) {
+                        xml.readNext();
+                        if (xml.isStartElement() && xml.name() == "devices") {
+                            if (xml.attributes().value("version") == "1.0") {
+                                while (!(xml.isEndElement() && xml.name() == "devices") && !xml.atEnd()) {
+                                    xml.readNext();
+                                    if (xml.isStartElement() && xml.name() == "device") {
+                                        const bool isDefault =  xml.attributes().value("default") == "yes";
+                                        const QString id = xml.attributes().value("id").toString();
+                                        const QString name =  xml.attributes().value("name").toString();
+                                        const bool epocDeviceMatch = (id + ":" + name) == epocDeviceValue;
+                                        epocDeviceFound |= epocDeviceMatch;
+
+                                        if((epocDeviceValue.isEmpty() && isDefault) || epocDeviceMatch) {
+                                            // Found a matching device
+                                            while (!(xml.isEndElement() && xml.name() == "device") && !xml.atEnd()) {
+                                                xml.readNext();
+                                                if (xml.isStartElement() && xml.name() == "epocroot") {
+                                                    epocRootValue = xml.readElementText();
+                                                    const QString deviceSource = epocDeviceValue.isEmpty()
+                                                        ? "default device"
+                                                        : "EPOCDEVICE (" + epocDeviceValue + ")";
+                                                    checkEpocRootExists(deviceSource);
+                                                }
+                                            }
+
+                                            if (epocRootValue.isEmpty())
+                                                xml.raiseError("No epocroot element found");
+                                        }
+                                    }
+                                }
+                            } else {
+                                xml.raiseError("Invalid 'devices' element version");
+                            }
+                        }
+                    }
+                    if (xml.hasError()) {
+                        std::cerr << "Error: \"" << xml.errorString() << "\" when parsing devices.xml" << std::endl;
+                    } else {
+                        if (epocRootValue.isEmpty()) {
+                            if (!epocDeviceValue.isEmpty()) {
+                                if (epocDeviceFound) {
+                                    std::cerr << "Error: missing or invalid epocroot attribute "
+                                              << "in device '" << epocDeviceValue << "'";
+                                } else {
+                                    std::cerr << "Error: no device matching EPOCDEVICE ("
+                                              << epocDeviceValue << ")";
+                                }
+                            } else {
+                                if (epocDeviceFound) {
+                                    std::cerr << "Error: missing or invalid epocroot attribute "
+                                              << "in default device";
+                                } else {
+                                    std::cerr << "Error: no default device";
+                                }
+                            }
+                            std::cerr << " found in devices.xml file." << std::endl;
+                        }
+                    }
+                } else {
+                    std::cerr << "Error: could not open file " << devicesXmlPath << std::endl;
+                }
+            }
+        }
+
+        if (epocRootValue.isEmpty()) {
+            // 5. An empty string is returned.
+            std::cerr << "Error: failed to find epoc root" << std::endl
+                 << "Either" << std::endl
+                 << "    1. Set EPOCROOT environment variable to a valid value" << std::endl
+                 << " or 2. Ensure that the HKEY_LOCAL_MACHINE\\" SYMBIAN_SDKS_REG_SUBKEY
+                    " registry key is set, and then" << std::endl
+                 << "       a. Set EPOCDEVICE environment variable to a valid device" << std::endl
+                 << "    or b. Specify a default device in the devices.xml file." << std::endl;
+        } else {
+            fixEpocRoot(epocRootValue);
+        }
+    }
+
+    return epocRootValue;
+}
+
diff --git a/qmake/generators/symbian/epocroot.h b/tools/shared/symbian/epocroot.h
index be26438..9846485 100644
--- a/qmake/generators/symbian/epocroot.h
+++ b/tools/shared/symbian/epocroot.h
@@ -39,13 +39,29 @@
 **
 ****************************************************************************/
 
-#ifndef EPOCROOT_H
-#define EPOCROOT_H
+#ifndef SYMBIAN_EPOCROOT_H
+#define SYMBIAN_EPOCROOT_H
 
-#include <qstring.h>
+#include <QtCore/qstring.h>
 
-// Implementation of epocRoot method is in initprojectdeploy_symbian.cpp
-// Defined in separate header for inclusion clarity
-extern QString epocRoot();
+/**
+ * Determine the epoc root for the currently active SDK.
+ *
+ * The algorithm used is as follows:
+ * 1. If environment variable EPOCROOT is set and points to an existent
+ *    directory, this is returned.
+ * 2. The location of devices.xml is specified by a registry key.  If this
+ *    file exists, it is parsed.
+ * 3. If the EPOCDEVICE environment variable is set and a corresponding
+ *    entry is found in devices.xml, and its epocroot value points to an
+ *    existent directory, it is returned.
+ * 4. If a device element marked as default is found in devices.xml and its
+ *    epocroot value points to an existent directory, this is returned.
+ * 5. An empty string is returned.
+ *
+ * Any return value other than the empty string therefore is guaranteed to
+ * point to an existent directory.
+ */
+QString epocRoot();
 
 #endif // EPOCROOT_H