Autogen: Add ManySources test

The QtAutogen/ManySources test generates a number of source, header, .ui and
.qrc files that get AUTOMOC, AUTOUIC and AUTORCC processed.  This stresses the
concurrency framework in `cmQtAutoMocUic` and should reveal any issues
with that.
diff --git a/Tests/QtAutogen/ManySources/CMakeLists.txt b/Tests/QtAutogen/ManySources/CMakeLists.txt
new file mode 100644
index 0000000..df8a2a6
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/CMakeLists.txt
@@ -0,0 +1,35 @@
+cmake_minimum_required(VERSION 3.10)
+project(ManySources)
+include("../AutogenGuiTest.cmake")
+
+# Test AUTOMOC and AUTOUIC on many source files to stress the concurrent
+# parsing and processing framework.
+
+set(CSD ${CMAKE_CURRENT_SOURCE_DIR})
+set(CBD ${CMAKE_CURRENT_BINARY_DIR})
+
+set(SRCS main.cpp)
+set(MAIN_INCLUDES "\n// Item includes\n")
+set(MAIN_ITEMS "\n// Items\n")
+
+set(NUM 24)
+foreach(III RANGE 1 ${NUM})
+  configure_file(${CSD}/object.h.in ${CBD}/object_${III}.h)
+  configure_file(${CSD}/item.h.in ${CBD}/item_${III}.h)
+  configure_file(${CSD}/item.cpp.in ${CBD}/item_${III}.cpp)
+  configure_file(${CSD}/view.ui.in ${CBD}/view_${III}.ui)
+  configure_file(${CSD}/data.qrc.in ${CBD}/data_${III}.qrc)
+
+  list(APPEND SRCS ${CBD}/item_${III}.cpp)
+  list(APPEND SRCS ${CBD}/data_${III}.qrc)
+
+  string(APPEND MAIN_INCLUDES "#include \"item_${III}.h\"\n")
+  string(APPEND MAIN_ITEMS "Item_${III} item_${III};\n")
+  string(APPEND MAIN_ITEMS "item_${III}.TheSlot();\n")
+endforeach()
+
+configure_file(${CSD}/main.cpp.in ${CBD}/main.cpp)
+
+add_executable(manySources ${SRCS} ${CBD}/main.cpp)
+target_link_libraries(manySources ${QT_LIBRARIES})
+set_target_properties(manySources PROPERTIES AUTOMOC 1 AUTOUIC 1 AUTORCC 1)
diff --git a/Tests/QtAutogen/ManySources/data.qrc.in b/Tests/QtAutogen/ManySources/data.qrc.in
new file mode 100644
index 0000000..870d486
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/data.qrc.in
@@ -0,0 +1,7 @@
+<!DOCTYPE RCC><RCC version="1.0">
+<qresource>
+  <file>object_@III@.h</file>
+  <file>item_@III@.h</file>
+  <file>item_@III@.cpp</file>
+</qresource>
+</RCC>
diff --git a/Tests/QtAutogen/ManySources/item.cpp.in b/Tests/QtAutogen/ManySources/item.cpp.in
new file mode 100644
index 0000000..c34ad16
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/item.cpp.in
@@ -0,0 +1,27 @@
+#include "item_@III@.h"
+#include "object_@III@.h"
+// AUTOUIC include
+#include <ui_view_@III@.h>
+
+class LocalObject_@III@ : public QObject
+{
+  Q_OBJECT;
+
+public:
+  LocalObject_@III@() = default;
+  ~LocalObject_@III@() = default;
+};
+
+void Item_@III@ ::TheSlot()
+{
+  LocalObject_@III@ localObject;
+  Object_@III@ obj;
+  obj.ObjectSlot();
+
+  Ui_View_@III@ ui_view;
+}
+
+// AUTOMOC includes
+#include "item_@III@.moc"
+#include "moc_item_@III@.cpp"
+#include "moc_object_@III@.cpp"
diff --git a/Tests/QtAutogen/ManySources/item.h.in b/Tests/QtAutogen/ManySources/item.h.in
new file mode 100644
index 0000000..67ad794
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/item.h.in
@@ -0,0 +1,15 @@
+#ifndef ITEM_@III@HPP
+#define ITEM_@III@HPP
+
+#include <QObject>
+
+class Item_@III@ : public QObject
+{
+  Q_OBJECT
+
+public:
+  Q_SLOT
+  void TheSlot();
+};
+
+#endif
diff --git a/Tests/QtAutogen/ManySources/main.cpp.in b/Tests/QtAutogen/ManySources/main.cpp.in
new file mode 100644
index 0000000..e1dda40
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/main.cpp.in
@@ -0,0 +1,7 @@
+@MAIN_INCLUDES@
+
+int main(int argv, char** args)
+{
+  @MAIN_ITEMS@
+  return 0;
+}
diff --git a/Tests/QtAutogen/ManySources/object.h.in b/Tests/QtAutogen/ManySources/object.h.in
new file mode 100644
index 0000000..a747cbc
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/object.h.in
@@ -0,0 +1,15 @@
+#ifndef OBJECT_@III@H
+#define OBJECT_@III@H
+
+#include <QObject>
+
+class Object_@III@ : public QObject
+{
+  Q_OBJECT
+
+public:
+  Q_SLOT
+  void ObjectSlot(){};
+};
+
+#endif
diff --git a/Tests/QtAutogen/ManySources/view.ui.in b/Tests/QtAutogen/ManySources/view.ui.in
new file mode 100644
index 0000000..6901fe3
--- /dev/null
+++ b/Tests/QtAutogen/ManySources/view.ui.in
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>View_@III@</class>
+ <widget class="QWidget" name="Base">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QHBoxLayout" name="horizontalLayout">
+   <item>
+    <widget class="QTreeView" name="treeView"/>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/Tests/QtAutogen/Tests.cmake b/Tests/QtAutogen/Tests.cmake
index 096d5e3..6771828 100644
--- a/Tests/QtAutogen/Tests.cmake
+++ b/Tests/QtAutogen/Tests.cmake
@@ -5,6 +5,7 @@
 ADD_AUTOGEN_TEST(Complex QtAutogen)
 ADD_AUTOGEN_TEST(GlobalAutogenTarget)
 ADD_AUTOGEN_TEST(LowMinimumVersion lowMinimumVersion)
+ADD_AUTOGEN_TEST(ManySources manySources)
 ADD_AUTOGEN_TEST(MocOnly mocOnly)
 ADD_AUTOGEN_TEST(MocOptions mocOptions)
 ADD_AUTOGEN_TEST(ObjectLibrary someProgram)