Help: Move Qt tool invocation information to a generic cmake-qt manual.

Add an introduction about the use of different package types, and the
ability to use Qt 4 and 5 versions together in a single buildsystem.

Add a section about automatic linking of the qtmain.lib library and
how to disable it.

3 files changed, 142 insertions, 72 deletions

diff --git a/Help/index.rst b/Help/index.rst
index 551db75..7fce223 100644
--- a/Help/index.rst
+++ b/Help/index.rst
@@ -35,6 +35,7 @@ Reference Manuals
    /manual/cmake-packages.7
    /manual/cmake-policies.7
    /manual/cmake-properties.7
+   /manual/cmake-qt.7
    /manual/cmake-toolchains.7
    /manual/cmake-variables.7
 
diff --git a/Help/manual/cmake-qt.7.rst b/Help/manual/cmake-qt.7.rst
new file mode 100644
index 0000000..a318afb
--- /dev/null
+++ b/Help/manual/cmake-qt.7.rst
@@ -0,0 +1,140 @@
+.. cmake-manual-description: CMake Qt Features Reference
+
+cmake-qt(7)
+***********
+
+.. only:: html or latex
+
+   .. contents::
+
+Introduction
+============
+
+CMake can find and use Qt 4 and Qt 5 libraries.  The Qt 4 libraries are found
+by the :module:`FindQt4` find-module shipped with CMake, whereas the
+Qt 5 libraries are found using "Config-file Packages" shipped with Qt 5. See
+:manual:`cmake-packages(7)` for more information about CMake packages, and
+see `the Qt cmake manual <http://qt-project.org/doc/qt-5/cmake-manual.html>`_
+for your Qt version.
+
+Qt 4 and Qt 5 may be used together in the same
+:manual:`CMake buildsystem <cmake-buildsystem(7)>`:
+
+.. code-block:: cmake
+
+  cmake_minimum_required(VERSION 3.0.0 FATAL_ERROR)
+
+  project(Qt4And5)
+
+  set(CMAKE_AUTOMOC ON)
+  set(CMAKE_INCLUDE_CURRENT_DIR ON)
+
+  find_package(Qt5Widgets REQUIRED)
+  add_executable(publisher publisher.cpp)
+  target_link_libraries(publisher Qt5::Widgets Qt5::DBus)
+
+  find_package(Qt4 REQUIRED)
+  add_executable(subscriber subscriber.cpp)
+  target_link_libraries(subscriber Qt4::QtGui Qt4::QtDBus)
+
+A CMake target may not link to both Qt 4 and Qt 5.  A diagnostic is issued if
+this is attempted or results from transitive target dependency evaluation.
+
+Qt Build Tools
+==============
+
+Qt relies on some bundled tools for code generation, such as ``moc`` for
+meta-object code generation, ``uic`` for widget layout and population,
+and ``rcc`` for virtual filesystem content generation.  These tools may be
+automatically invoked by :manual:`cmake(1)` if the appropriate conditions
+are met.  The automatic tool invocation may be used with both Qt 4 and Qt 5.
+
+The tools are executed as part of a synthesized custom target generated by
+CMake.  Target dependencies may be added to that custom target by adding them
+to the :prop_tgt:`AUTOGEN_TARGET_DEPENDS` target property.
+
+AUTOMOC
+'''''''
+
+The :prop_tgt:`AUTOMOC` target property controls whether :manual:`cmake(1)`
+inspects the C++ files in the target to determine if they require ``moc`` to
+be run, and to create rules to execute ``moc`` at the appropriate time.
+
+If a ``Q_OBJECT`` or ``Q_GADGET`` macro is found in a header file, ``moc``
+will be run on the file.  The result will be put into a file named according
+to ``moc_<basename>.cpp``.  If the macro is found in a C++ implementation
+file, the moc output will be put into a file named according to
+``<basename>.moc``, following the Qt conventions.  The ``moc file`` may be
+included by the user in the C++ implementation file with a preprocessor
+``#include``.  If it is not so included, it will be added to a separate file
+which is compiled into the target.
+
+Generated ``moc_*.cpp`` and ``*.moc`` files are placed in the build directory
+so it is convenient to set the :variable:`CMAKE_INCLUDE_CURRENT_DIR`
+variable.  The :prop_tgt:`AUTOMOC` target property may be pre-set for all
+following targets by setting the :variable:`CMAKE_AUTOMOC` variable.  The
+:prop_tgt:`AUTOMOC_MOC_OPTIONS` target property may be populated to set
+options to pass to ``moc``. The :variable:`CMAKE_AUTOMOC_MOC_OPTIONS`
+variable may be populated to pre-set the options for all following targets.
+
+AUTOUIC
+'''''''
+
+The :prop_tgt:`AUTOUIC` target property controls whether :manual:`cmake(1)`
+inspects the C++ files in the target to determine if they require ``uic`` to
+be run, and to create rules to execute ``uic`` at the appropriate time.
+
+If a preprocessor ``#include`` directive is found which matches
+``ui_<basename>.h``, and a ``<basename>.ui`` file exists, then ``uic`` will
+be executed to generate the appropriate file.
+
+Generated ``ui_*.h`` files are placed in the build directory so it is
+convenient to set the :variable:`CMAKE_INCLUDE_CURRENT_DIR` variable.  The
+:prop_tgt:`AUTOUIC` target property may be pre-set for all following targets
+by setting the :variable:`CMAKE_AUTOUIC` variable.  The
+:prop_tgt:`AUTOUIC_OPTIONS` target property may be populated to set options
+to pass to ``uic``.  The :variable:`CMAKE_AUTOUIC_OPTIONS` variable may be
+populated to pre-set the options for all following targets.  The
+:prop_sf:`AUTOUIC_OPTIONS` source file property may be set on the
+``<basename>.ui`` file to set particular options for the file.  This
+overrides options from the :prop_tgt:`AUTOUIC_OPTIONS` target property.
+
+AUTORCC
+'''''''
+
+The :prop_tgt:`AUTORCC` target property controls whether :manual:`cmake(1)`
+creates rules to execute ``rcc`` at the appropriate time on source files
+which have the suffix ``.qrc``.
+
+.. code-block:: cmake
+
+  add_executable(myexe main.cpp resource_file.qrc)
+
+The :prop_tgt:`AUTORCC` target property may be pre-set for all following targets
+by setting the :variable:`CMAKE_AUTORCC` variable.  The
+:prop_tgt:`AUTORCC_OPTIONS` target property may be populated to set options
+to pass to ``rcc``.  The :variable:`CMAKE_AUTORCC_OPTIONS` variable may be
+populated to pre-set the options for all following targets.  The
+:prop_sf:`AUTORCC_OPTIONS` source file property may be set on the
+``<name>.qrc`` file to set particular options for the file.  This
+overrides options from the :prop_tgt:`AUTORCC_OPTIONS` target property.
+
+qtmain.lib on Windows
+=====================
+
+The Qt 4 and 5 :prop_tgt:`IMPORTED` targets for the QtGui libraries specify
+that the qtmain.lib static library shipped with Qt will be linked by all
+dependent executables which have the :prop_tgt:`WIN32_EXECUTABLE` enabled.
+
+Do disable this behavior, enable the ``Qt5_NO_LINK_QTMAIN`` target property for
+Qt 5 based targets or ``QT4_NO_LINK_QTMAIN`` target property for Qt 4 based
+targets.
+
+.. code-block:: cmake
+
+  add_executable(myexe WIN32 main.cpp)
+  target_link_libraries(myexe Qt4::QtGui)
+
+  add_executable(myexe_no_qtmain WIN32 main_no_qtmain.cpp)
+  set_property(TARGET main_no_qtmain PROPERTY QT4_NO_LINK_QTMAIN ON)
+  target_link_libraries(main_no_qtmain Qt4::QtGui)
diff --git a/Modules/FindQt4.cmake b/Modules/FindQt4.cmake
index 2d2feae..21a853d 100644
--- a/Modules/FindQt4.cmake
+++ b/Modules/FindQt4.cmake
@@ -35,78 +35,7 @@
 # meta-object code generation,``uic`` for widget layout and population,
 # and ``rcc`` for virtual filesystem content generation.  These tools may be
 # automatically invoked by :manual:`cmake(1)` if the appropriate conditions
-# are met.
-#
-# The tools are executed as part of a synthesized custom target generated by
-# CMake.  Target dependencies may be added to that custom target by adding them
-# to the :prop_tgt:`AUTOGEN_TARGET_DEPENDS` target property.
-#
-# AUTOMOC
-# '''''''
-#
-# The :prop_tgt:`AUTOMOC` target property controls whether :manual:`cmake(1)`
-# inspects the C++ files in the target to determine if they require ``moc`` to
-# be run, and to create rules to execute ``moc`` at the appropriate time.
-#
-# If a ``Q_OBJECT`` or ``Q_GADGET`` macro is found in a header file, ``moc``
-# will be run on the file.  The result will be put into a file named according
-# to ``moc_<basename>.cpp``.  If the macro is found in a C++ implementation
-# file, the moc output will be put into a file named according to
-# ``<basename>.moc``, following the Qt conventions.  The ``moc file`` may be
-# included by the user in the C++ implementation file with a preprocessor
-# ``#include``.  If it is not so included, it will be added to a separate file
-# which is compiled into the target.
-#
-# Generated ``moc_*.cpp`` and ``*.moc`` files are placed in the build directory
-# so it is convenient to set the :variable:`CMAKE_INCLUDE_CURRENT_DIR`
-# variable.  The :prop_tgt:`AUTOMOC` target property may be pre-set for all
-# following targets by setting the :variable:`CMAKE_AUTOMOC` variable.  The
-# :prop_tgt:`AUTOMOC_MOC_OPTIONS` target property may be populated to set
-# options to pass to ``moc``. The :variable:`CMAKE_AUTOMOC_MOC_OPTIONS`
-# variable may be populated to pre-set the options for all following targets.
-#
-# AUTOUIC
-# '''''''
-#
-# The :prop_tgt:`AUTOUIC` target property controls whether :manual:`cmake(1)`
-# inspects the C++ files in the target to determine if they require ``uic`` to
-# be run, and to create rules to execute ``uic`` at the appropriate time.
-#
-# If a preprocessor ``#include`` directive is found which matches
-# ``ui_<basename>.h``, and a ``<basename>.ui`` file exists, then ``uic`` will
-# be executed to generate the appropriate file.
-#
-# Generated ``ui_*.h`` files are placed in the build directory so it is
-# convenient to set the :variable:`CMAKE_INCLUDE_CURRENT_DIR` variable.  The
-# :prop_tgt:`AUTOUIC` target property may be pre-set for all following targets
-# by setting the :variable:`CMAKE_AUTOUIC` variable.  The
-# :prop_tgt:`AUTOUIC_OPTIONS` target property may be populated to set options
-# to pass to ``uic``.  The :variable:`CMAKE_AUTOUIC_OPTIONS` variable may be
-# populated to pre-set the options for all following targets.  The
-# :prop_sf:`AUTOUIC_OPTIONS` source file property may be set on the
-# ``<basename>.ui`` file to set particular options for the file.  This
-# overrides options from the :prop_tgt:`AUTOUIC_OPTIONS` target property.
-#
-# AUTORCC
-# '''''''
-#
-# The :prop_tgt:`AUTORCC` target property controls whether :manual:`cmake(1)`
-# creates rules to execute ``rcc`` at the appropriate time on source files
-# which have the suffix ``.qrc``.
-#
-# .. code-block:: cmake
-#
-#   add_executable(myexe main.cpp resource_file.qrc)
-#
-# The :prop_tgt:`AUTORCC` target property may be pre-set for all following targets
-# by setting the :variable:`CMAKE_AUTORCC` variable.  The
-# :prop_tgt:`AUTORCC_OPTIONS` target property may be populated to set options
-# to pass to ``rcc``.  The :variable:`CMAKE_AUTORCC_OPTIONS` variable may be
-# populated to pre-set the options for all following targets.  The
-# :prop_sf:`AUTORCC_OPTIONS` source file property may be set on the
-# ``<name>.qrc`` file to set particular options for the file.  This
-# overrides options from the :prop_tgt:`AUTORCC_OPTIONS` target property.
-#
+# are met.  See :manual:`cmake-qt(7)` for more.
 #
 # Qt Macros
 # =========