Doc: Add documentation for ADDITIONAL_CLEAN_FILES properties

Help/manual/cmake-properties.7.rst

@@ -61,6 +61,7 @@ Properties on Directories
 .. toctree::
    :maxdepth: 1
 
+   /prop_dir/ADDITIONAL_CLEAN_FILES
    /prop_dir/ADDITIONAL_MAKE_CLEAN_FILES
    /prop_dir/BINARY_DIR
    /prop_dir/BUILDSYSTEM_TARGETS
@@ -102,6 +103,7 @@ Properties on Targets
 .. toctree::
    :maxdepth: 1
 
+   /prop_tgt/ADDITIONAL_CLEAN_FILES
    /prop_tgt/ALIASED_TARGET
    /prop_tgt/ANDROID_ANT_ADDITIONAL_OPTIONS
    /prop_tgt/ANDROID_API

Help/prop_dir/ADDITIONAL_CLEAN_FILES.rst

@@ -0,0 +1,16 @@
+ADDITIONAL_CLEAN_FILES
+----------------------
+
+Additional files to remove during the clean stage.
+
+A :ref:`;-list <CMake Language Lists>` of files that will be removed as a
+part of the ``clean`` target.
+
+Relative paths are allowed and are interpreted relative to the
+current binary directory.
+
+Arguments to :prop_dir:`ADDITIONAL_CLEAN_FILES` may use
+:manual:`generator expressions <cmake-generator-expressions(7)>`.
+
+This property only works for the :generator:`Ninja` and the Makefile
+generators.  It is ignored on other generators.

Help/prop_tgt/ADDITIONAL_CLEAN_FILES.rst

@@ -0,0 +1,16 @@
+ADDITIONAL_CLEAN_FILES
+----------------------
+
+Additional files to remove during the clean stage.
+
+A :ref:`;-list <CMake Language Lists>` of files that will be removed as a
+part of the ``clean`` target.
+
+Relative paths are allowed and are interpreted relative to the
+current binary directory.
+
+Arguments to :prop_tgt:`ADDITIONAL_CLEAN_FILES` may use
+:manual:`generator expressions <cmake-generator-expressions(7)>`.
+
+This property only works for the :generator:`Ninja` and the Makefile
+generators.  It is ignored on other generators.