CPack: Introduce pre- and post- build actions

CPack learned the `CPACK_PRE_BUILD_SCRIPTS`, `CPACK_POST_BUILD_SCRIPTS`,
and `CPACK_PACKAGE_FILES` variables.

The first two are lists of scripts to perform
- after pre-install files into a staging directory and before
  producing the resulting packages
- after produsing the packages

The post-build script(s) also get the list of actually produced
packages in the `CPACK_PACKAGE_FILES`.

Issue: #19077

1 files changed, 15 insertions, 0 deletions

diff --git a/Modules/CPack.cmake b/Modules/CPack.cmake
index 6234b9d..553b966 100644
--- a/Modules/CPack.cmake
+++ b/Modules/CPack.cmake
@@ -386,6 +386,21 @@ The following variables are for advanced uses of CPack:
   select the CPack generator(s) to be used when building the ``package``
   target or when running :manual:`cpack <cpack(1)>` without the ``-G`` option.
 
+.. variable:: CPACK_PRE_BUILD_SCRIPTS
+
+  List of CMake scripts to execute after CPack has installed the files to
+  be packed into a staging directory and before producing the result
+  packages.
+
+.. variable:: CPACK_POST_BUILD_SCRIPTS
+
+  List of CMake scripts to execute after CPack has produced the result
+  packages and before copying them back to a build directory.
+
+.. variable:: CPACK_PACKAGE_FILES
+
+  List of resulting package files passed to the ``CPACK_POST_BUILD_SCRIPTS``.
+
 #]=======================================================================]
 
 # Define this var in order to avoid (or warn) concerning multiple inclusion