Help: Improve accuracy, readability and cross-referencing of cpack docs

This is primarily a cleanup of the cpack(1) page. The cpack.cxx file
and CPack module were also updated to make the docs relating to
the generator specification and option names consistent in all
three places.

1 files changed, 58 insertions, 65 deletions

diff --git a/Help/manual/cpack.1.rst b/Help/manual/cpack.1.rst
index 105bb67..87aa38d 100644
--- a/Help/manual/cpack.1.rst
+++ b/Help/manual/cpack.1.rst
@@ -8,92 +8,85 @@ Synopsis
 
 .. parsed-literal::
 
- cpack -G <generator> [<options>]
+ cpack [<options>]
 
 Description
 ===========
 
-The "cpack" executable is the CMake packaging program.
-CMake-generated build trees created for projects that use the
-INSTALL_* commands have packaging support.  This program will generate
-the package.
-
-CMake is a cross-platform build system generator.  Projects specify
-their build process with platform-independent CMake listfiles included
-in each directory of a source tree with the name CMakeLists.txt.
-Users build a project by using CMake to generate a build system for a
-native tool on their platform.
+The ``cpack`` executable is the CMake packaging program.
+CMake projects use :command:`install` commands to define the contents of
+packages which can be generated in various formats by this tool.
+The :module:`CPack` module greatly simplifies the creation of the input file
+used by ``cpack``, allowing most aspects of the packaging configuration to be
+controlled directly from the CMake project's own ``CMakeLists.txt`` files.
 
 Options
 =======
 
-``-G <generator>``
- Use the specified generator to generate package.
-
- CPack may support multiple native packaging systems on certain
- platforms.  A generator is responsible for generating input files
- for particular system and invoking that systems.  Possible generator
- names are specified in the Generators section.
+``-G <generators>``
+  ``<generators>`` is a :ref:`semicolon-separated list <CMake Language Lists>`
+  of generator names.  ``cpack`` will iterate through this list and produce
+  package(s) in that generator's format according to the details provided in
+  the ``CPackConfig.cmake`` configuration file.  A generator is responsible for
+  generating the required inputs for a particular package system and invoking
+  that system's package creation tools.  Possible generator names are specified
+  in the :manual:`Generators <cmake-generators(7)>` section of the manual and
+  the ``--help`` option lists the generators supported for the target platform.
+  If this option is not given, the :variable:`CPACK_GENERATOR` variable
+  determines the default set of generators that will be used.
 
 ``-C <Configuration>``
- Specify the project configuration
-
- This option specifies the configuration that the project was build
- with, for example 'Debug', 'Release'.
+  Specify the project configuration to be packaged (e.g. ``Debug``,
+  ``Release``, etc.).  When the CMake project uses a multi-configuration
+  generator such as Xcode or Visual Studio, this option is needed to tell
+  ``cpack`` which built executables to include in the package.
 
 ``-D <var>=<value>``
- Set a CPack variable.
-
- Set a variable that can be used by the generator.
+  Set a CPack variable.  This will override any value set for ``<var>`` in the
+  input file read by ``cpack``.
 
-``--config <config file>``
- Specify the config file.
-
- Specify the config file to use to create the package.  By default
- CPackConfig.cmake in the current directory will be used.
+``--config <configFile>``
+  Specify the configuration file read by ``cpack`` to provide the packaging
+  details.  By default, ``CPackConfig.cmake`` in the current directory will
+  be used.
 
 ``--verbose,-V``
- enable verbose output
-
- Run cpack with verbose output.
+  Run ``cpack`` with verbose output.  This can be used to show more details
+  from the package generation tools and is suitable for project developers.
 
 ``--debug``
- enable debug output (for CPack developers)
-
- Run cpack with debug output (for CPack developers).
+  Run ``cpack`` with debug output.  This option is intended mainly for the
+  developers of ``cpack`` itself and is not normally needed by project
+  developers.
 
 ``--trace``
- Put underlying cmake scripts in trace mode.
+  Put the underlying cmake scripts in trace mode.
 
 ``--trace-expand``
- Put underlying cmake scripts in expanded trace mode.
-
-``-P <package name>``
- override/define CPACK_PACKAGE_NAME
-
- If the package name is not specified on cpack command line
- thenCPack.cmake defines it as CMAKE_PROJECT_NAME
-
-``-R <package version>``
- override/define CPACK_PACKAGE_VERSION
-
- If version is not specified on cpack command line thenCPack.cmake
- defines it from CPACK_PACKAGE_VERSION_[MAJOR|MINOR|PATCH]look into
- CPack.cmake for detail
-
-``-B <package directory>``
- override/define CPACK_PACKAGE_DIRECTORY
-
- The directory where CPack will be doing its packaging work.The
- resulting package will be found there.  Inside this directoryCPack
- creates '_CPack_Packages' sub-directory which is theCPack temporary
- directory.
-
-``--vendor <vendor name>``
- override/define CPACK_PACKAGE_VENDOR
-
- If vendor is not specified on cpack command line (or inside
- CMakeLists.txt) thenCPack.cmake defines it with a default value
+  Put the underlying cmake scripts in expanded trace mode.
+
+``-P <packageName>``
+  Override/define the value of the :variable:`CPACK_PACKAGE_NAME` variable used
+  for packaging.  Any value set for this variable in the ``CPackConfig.cmake``
+  file will then be ignored.
+
+``-R <packageVersion>``
+  Override/define the value of the :variable:`CPACK_PACKAGE_VERSION`
+  variable used for packaging.  It will override a value set in the
+  ``CPackConfig.cmake`` file or one automatically computed from
+  :variable:`CPACK_PACKAGE_VERSION_MAJOR`,
+  :variable:`CPACK_PACKAGE_VERSION_MINOR` and
+  :variable:`CPACK_PACKAGE_VERSION_PATCH`.
+
+``-B <packageDirectory>``
+  Override/define :variable:`CPACK_PACKAGE_DIRECTORY`, which controls the
+  directory where CPack will perform its packaging work.  The resultant
+  package(s) will be created at this location by default and a
+  ``_CPack_Packages`` subdirectory will also be created below this directory to
+  use as a working area during package creation.
+
+``--vendor <vendorName>``
+  Override/define :variable:`CPACK_PACKAGE_VENDOR`.
 
 .. include:: OPTIONS_HELP.txt