Mark QtWidgets as free of Q_FOREACH, except where it isn't

The density of Q_FOREACH uses is high here, too high for this author
to tackle in a short amount of time. But they're concentrated in just
a few TUs, so pick a different strategy:

Mark the whole library with QT_NO_FOREACH, to prevent new uses from
creeping in, and whitelist the affected TUs by #undef'ing
QT_NO_FOREACH locally, at the top of each file. For TUs that are part
of a larger executable, this requires these files to be compiled
separately, so add them to NO_PCH_SOURCES (which implies
NO_UNITY_BUILD_SOURCES, too). Created QTBUG-115803 to keep track of
this.

Task-number: QTBUG-115803
Change-Id: Ib5d6192632d98bdcc6625a9a14e05d13bb7f759b
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>

src/widgets/CMakeLists.txt

@@ -53,6 +53,7 @@ qt_internal_add_module(Widgets
     DEFINES
         QT_NO_CONTEXTLESS_CONNECT
         QT_NO_USING_NAMESPACE
+        QT_NO_FOREACH # mostly...
     INCLUDE_DIRECTORIES
         dialogs
     LIBRARIES
@@ -68,6 +69,8 @@ qt_internal_add_module(Widgets
         "kernel/qt_widgets_pch.h"
     NO_PCH_SOURCES
         compat/removed_api.cpp
+        kernel/qgesturemanager.cpp # undef QT_NO_FOREACH
+        kernel/qwidgetrepaintmanager.cpp # undef QT_NO_FOREACH
     GENERATE_CPP_EXPORTS
 )
 
@@ -470,6 +473,8 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_mdiarea
     SOURCES
         widgets/qmdiarea.cpp widgets/qmdiarea.h widgets/qmdiarea_p.h
         widgets/qmdisubwindow.cpp widgets/qmdisubwindow.h widgets/qmdisubwindow_p.h
+    NO_PCH_SOURCES
+        widgets/qmdiarea.cpp # undef QT_NO_FOREACH
 )
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_menu
@@ -480,6 +485,8 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_menu
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_menubar
     SOURCES
         widgets/qmenubar.cpp widgets/qmenubar.h widgets/qmenubar_p.h
+    NO_PCH_SOURCES
+        widgets/qmenubar.cpp # undef QT_NO_FOREACH
 )
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_progressbar
@@ -726,6 +733,8 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_itemviews
         itemviews/qitemeditorfactory.cpp itemviews/qitemeditorfactory.h itemviews/qitemeditorfactory_p.h
         itemviews/qstyleditemdelegate.cpp itemviews/qstyleditemdelegate.h
         itemviews/qwidgetitemdata_p.h
+    NO_PCH_SOURCES
+        itemviews/qabstractitemview.cpp # undef QT_NO_FOREACH
 )
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_columnview
@@ -752,6 +761,8 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_listwidget
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_tableview
     SOURCES
         itemviews/qtableview.cpp itemviews/qtableview.h itemviews/qtableview_p.h
+    NO_PCH_SOURCES
+        itemviews/qtableview.cpp # undef QT_NO_FOREACH
 )
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_tablewidget
@@ -793,6 +804,8 @@ qt_internal_extend_target(Widgets CONDITION QT_FEATURE_graphicsview
         graphicsview/qgraphicsview.cpp graphicsview/qgraphicsview.h graphicsview/qgraphicsview_p.h
         graphicsview/qgraphicswidget.cpp graphicsview/qgraphicswidget.h graphicsview/qgraphicswidget_p.cpp graphicsview/qgraphicswidget_p.h
         graphicsview/qsimplex_p.cpp graphicsview/qsimplex_p.h
+    NO_PCH_SOURCES
+        graphicsview/qgraphicsanchorlayout_p.cpp # undef QT_NO_FOREACH
 )
 
 qt_internal_extend_target(Widgets CONDITION QT_FEATURE_easingcurve AND QT_FEATURE_graphicsview

src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 #include "qgraphicsanchorlayout_p.h"
 
 #include <QtWidgets/qwidget.h>

src/widgets/itemviews/qabstractitemview.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 #include "qabstractitemview.h"
 
 #include <qpointer.h>

src/widgets/itemviews/qtableview.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 #include "qtableview.h"
 
 #include <qheaderview.h>

src/widgets/kernel/qgesturemanager.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 #include "private/qgesturemanager_p.h"
 #include "private/qstandardgestures_p.h"
 #include "private/qwidget_p.h"

src/widgets/kernel/qwidgetrepaintmanager.cpp

@@ -1,6 +1,7 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
 
 #include "qplatformdefs.h"
 

src/widgets/widgets/qmdiarea.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 /*!
     \class QMdiArea
     \brief The QMdiArea widget provides an area in which MDI windows are displayed.

src/widgets/widgets/qmenubar.cpp

@@ -1,6 +1,8 @@
 // Copyright (C) 2016 The Qt Company Ltd.
 // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
+#undef QT_NO_FOREACH // this file contains unported legacy Q_FOREACH uses
+
 #include <qmenubar.h>
 
 #include <qstyle.h>