Windows: Include DirectWrite support by default if available

This will automatically add DirectWrite support if the required
headers are found. The note about platform support from the help
screen has also been removed, since Windows XP is not officially
supported. Applications that need to run on XP can still build
with -no-directwrite.

Also changed the configure test to be a proper compile test, since
cross-compiled builds for Windows CE may break otherwise.

Change-Id: I7fc7bfb25f2f86ced8a4d4c78a69527de0273707
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Konstantin Ritt <ritt.ks@gmail.com>

3 files changed, 55 insertions, 6 deletions

diff --git a/config.tests/win/directwrite/directwrite.cpp b/config.tests/win/directwrite/directwrite.cpp
new file mode 100644
index 0000000000..01bea19faf
--- /dev/null
+++ b/config.tests/win/directwrite/directwrite.cpp
@@ -0,0 +1,44 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the config.tests of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** 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 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <dwrite.h>
+#include <d2d1.h>
+
+int main(int, char**)
+{
+    IDWriteFactory *factory = 0;
+    DWriteCreateFactory(DWRITE_FACTORY_TYPE_SHARED,
+                        __uuidof(IDWriteFactory),
+                        reinterpret_cast<IUnknown **>(&factory));
+    return 0;
+}
diff --git a/config.tests/win/directwrite/directwrite.pro b/config.tests/win/directwrite/directwrite.pro
new file mode 100644
index 0000000000..9a4612ca11
--- /dev/null
+++ b/config.tests/win/directwrite/directwrite.pro
@@ -0,0 +1,4 @@
+SOURCES = directwrite.cpp
+LIBS += -ldwrite
+CONFIG -= qt
+CONFIG += console
diff --git a/tools/configure/configureapp.cpp b/tools/configure/configureapp.cpp
index c4e915b936..c4455eeb63 100644
--- a/tools/configure/configureapp.cpp
+++ b/tools/configure/configureapp.cpp
@@ -169,7 +169,7 @@ Configure::Configure(int& argc, char** argv)
     dictionary[ "WMSDK" ]           = "auto";
     dictionary[ "QML_DEBUG" ]       = "yes";
     dictionary[ "PLUGIN_MANIFESTS" ] = "no";
-    dictionary[ "DIRECTWRITE" ]     = "no";
+    dictionary[ "DIRECTWRITE" ]     = "auto";
     dictionary[ "DIRECT2D" ]        = "no";
     dictionary[ "NIS" ]             = "no";
     dictionary[ "NEON" ]            = "auto";
@@ -2010,8 +2010,8 @@ bool Configure::displayHelp()
         desc("WMF_BACKEND", "yes","-wmf-backend",       "Compile in the windows media foundation backend into Qt Multimedia.\n");
         desc("QML_DEBUG", "no",    "-no-qml-debug",     "Do not build the in-process QML debugging support.");
         desc("QML_DEBUG", "yes",   "-qml-debug",        "Build the in-process QML debugging support.\n");
-        desc("DIRECTWRITE", "no", "-no-directwrite", "Do not build support for DirectWrite font rendering.");
-        desc("DIRECTWRITE", "yes", "-directwrite", "Build support for DirectWrite font rendering (requires DirectWrite availability on target systems, e.g. Windows Vista with Platform Update, Windows 7, etc.)\n");
+        desc("DIRECTWRITE", "no", "-no-directwrite",    "Do not build support for DirectWrite font rendering.");
+        desc("DIRECTWRITE", "yes", "-directwrite",      "Build support for DirectWrite font rendering.\n");
 
         desc("DIRECT2D", "no",  "-no-direct2d",         "Do not build the Direct2D platform plugin.");
         desc("DIRECT2D", "yes", "-direct2d",            "Build the Direct2D platform plugin (experimental,\n"
@@ -2291,9 +2291,7 @@ bool Configure::checkAvailability(const QString &part)
     } else if (part == "WMF_BACKEND") {
         available = findFile("mfapi.h") && findFile("mf.lib");
     } else if (part == "DIRECTWRITE") {
-        const char *dwriteLibrary = Environment::detectCompiler() != CC_MINGW
-            ? "dwrite.lib" : "libdwrite.a";
-        available = findFile("dwrite.h") && findFile("d2d1.h") && findFile(QLatin1String(dwriteLibrary));
+        available = tryCompileProject("win/directwrite");
     } else if (part == "DIRECT2D") {
         available = tryCompileProject("qpa/direct2d");
     } else if (part == "ICONV") {
@@ -2512,6 +2510,9 @@ void Configure::autoDetection()
     if (dictionary["FONT_CONFIG"] == "auto")
         dictionary["FONT_CONFIG"] = checkAvailability("FONT_CONFIG") ? "yes" : "no";
 
+    if (dictionary["DIRECTWRITE"] == "auto")
+        dictionary["DIRECTWRITE"] = checkAvailability("DIRECTWRITE") ? "yes" : "no";
+
     // Mark all unknown "auto" to the default value..
     for (QMap<QString,QString>::iterator i = dictionary.begin(); i != dictionary.end(); ++i) {
         if (i.value() == "auto")