set_source_files_properties: Allow specification of directory scope

Both set_source_files_properties() and set_property(SOURCE) now accept
two new optional arguments: DIRECTORY and TARGET_DIRECTORY.

The DIRECTORY option takes a list of relative or absolute paths
pointing to processed source directories (add_subdirectory was
already called on them).

These paths specify directory scopes where the source file properties
will be set. Previously the scope was always the currently processed
source directory.

Similarly TARGET_DIRECTORY takes a list of targets, whose source
directories will be used as the list of scopes where to set the
source file properties.

get_property() and get_source_file_property() also get the same
new arguments, except only one value can be specified instead
of a list.

Fixes: #20128

1 files changed, 13 insertions, 0 deletions

diff --git a/Help/command/set_source_files_properties.rst b/Help/command/set_source_files_properties.rst
index ab95d70..8adfb9e 100644
--- a/Help/command/set_source_files_properties.rst
+++ b/Help/command/set_source_files_properties.rst
@@ -6,12 +6,25 @@ Source files can have properties that affect how they are built.
 .. code-block:: cmake
 
   set_source_files_properties([file1 [file2 [...]]]
+                              [<TARGET_DIRECTORY ... | DIRECTORY ...>]
                               PROPERTIES prop1 value1
                               [prop2 value2 [...]])
 
 Sets properties associated with source files using a key/value paired
 list.
 
+Note that source file properties are by default visible only to
+targets added in the same directory (``CMakeLists.txt``).
+
+The file properties can be made visible in a different directory by specifying
+one of the additional options: ``TARGET_DIRECTORY`` or ``DIRECTORY``.
+
+``DIRECTORY`` takes a list of processed directories paths, and sets the file
+properties in those directory scopes.
+
+``TARGET_DIRECTORY`` takes a list of existing targets. The file
+properties will be set in these targets' directory scopes.
+
 See also the :command:`set_property(SOURCE)` command.
 
 See :ref:`Source File Properties` for the list of properties known