Help: Add `.. versionadded` directives to commands documentation

This change ony concerns directives that appear in the document body.

The guidelines for inserting version directives:

 * Baseline version is CMake 3.0, i.e. directives start at 3.1.
 * Always use `.. versionadded::` directive, avoid ad-hoc version
   references. Exception: policy pages.
 * For new command signatures, put `versionadded` on a separate line
   after the signature.
 * For a group of new signatures in a new document section,
   a single version note at the beginning of the section is sufficient.
 * For new options, put `versionadded` on a separate line before
   option description.
 * If all the option descriptions in the list are short one-liners,
   it's fine to put `versionadded` on the same line as the description.
 * If multiple option descriptions in close proximity would have
   the same ..versionadded directive, consider adding a single
   directive after the list, mentioning all added options.
 * For compact value lists and sub-option lists, put a single
  `versionadded` directive after the list mentioning all additions.
 * When a change is described in a single paragraph, put
   `versionadded` into that paragraph.
 * When only part of the paragraph has changed, separate the changed
   part if it doesn't break the flow. Otherwise, write a follow-up
   clarification paragraph and apply version directive to that.
 * When multiple version directives are close by, order earlier
   additions before later additions.
 * Indent related lists and code blocks to include them in the scope
   of `versionadded` directive.

Issue: #19715

1 files changed, 16 insertions, 8 deletions

diff --git a/Help/command/target_sources.rst b/Help/command/target_sources.rst
index 07fb937..eb147ee 100644
--- a/Help/command/target_sources.rst
+++ b/Help/command/target_sources.rst
@@ -12,29 +12,37 @@ Add sources to a target.
     [<INTERFACE|PUBLIC|PRIVATE> [items2...] ...])
 
 Specifies sources to use when building a target and/or its dependents.
-Relative source file paths are interpreted as being relative to the current
-source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`).  The
-named ``<target>`` must have been created by a command such as
+The named ``<target>`` must have been created by a command such as
 :command:`add_executable` or :command:`add_library` or
 :command:`add_custom_target` and must not be an
 :ref:`ALIAS target <Alias Targets>`.
 
+.. versionadded:: 3.13
+  Relative source file paths are interpreted as being relative to the current
+  source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`).
+  See policy :policy:`CMP0076`.
+
+.. versionadded:: 3.20
+  ``<target>`` can be a custom target.
+
 The ``INTERFACE``, ``PUBLIC`` and ``PRIVATE`` keywords are required to
 specify the scope of the items following them.  ``PRIVATE`` and ``PUBLIC``
 items will populate the :prop_tgt:`SOURCES` property of
 ``<target>``, which are used when building the target itself.
 ``PUBLIC`` and ``INTERFACE`` items will populate the
 :prop_tgt:`INTERFACE_SOURCES` property of ``<target>``, which are used
-when building dependents.  (:ref:`IMPORTED targets <Imported Targets>`
-only support ``INTERFACE`` items because they are not build targets.)
+when building dependents.
 The following arguments specify sources.  Repeated calls for the same
 ``<target>`` append items in the order called. The targets created by
 :command:`add_custom_target` can only have ``PRIVATE`` scope.
 
+.. versionadded:: 3.3
+  Allow exporting targets with :prop_tgt:`INTERFACE_SOURCES`.
+
+.. versionadded:: 3.11
+  Allow setting ``INTERFACE`` items on :ref:`IMPORTED targets <Imported Targets>`.
+
 Arguments to ``target_sources`` may use "generator expressions"
 with the syntax ``$<...>``. See the :manual:`cmake-generator-expressions(7)`
 manual for available expressions.  See the :manual:`cmake-buildsystem(7)`
 manual for more on defining buildsystem properties.
-
-See also the :policy:`CMP0076` policy for older behavior related to the
-handling of relative source file paths.