cmTarget: Add a way to represent imported shared library stubs

Shared library stubs can be used for linking, but not at runtime.
Their role is similar to import libraries on Windows, so represent
their location with the `IMPORTED_IMPLIB` target property.

Fixes: #24940

2 files changed, 13 insertions, 0 deletions

diff --git a/Help/prop_tgt/IMPORTED_IMPLIB.rst b/Help/prop_tgt/IMPORTED_IMPLIB.rst
index e67acba..27601d2 100644
--- a/Help/prop_tgt/IMPORTED_IMPLIB.rst
+++ b/Help/prop_tgt/IMPORTED_IMPLIB.rst
@@ -11,6 +11,12 @@ This property may be set:
 * On macOS, to an import file (e.g. ``.tbd``) created for shared libraries (see
   the :prop_tgt:`ENABLE_EXPORTS` target property). For frameworks this is the
   location of the ``.tbd`` file symlink just inside the framework folder.
+* .. versionadded:: 3.28
+    On non-DLL platforms, to the location of a shared library.
+    When set without also specifying an :prop_tgt:`IMPORTED_LOCATION`,
+    the library is considered to be a stub, and its location will not
+    be added as a runtime search path to dependents that link it.
+
 
 The ``IMPORTED_IMPLIB`` target property may be overridden for a
 given configuration ``<CONFIG>`` by the configuration-specific
diff --git a/Help/release/dev/imported-implib-only.rst b/Help/release/dev/imported-implib-only.rst
new file mode 100644
index 0000000..aa817b7
--- /dev/null
+++ b/Help/release/dev/imported-implib-only.rst
@@ -0,0 +1,7 @@
+imported-implib-only
+--------------------
+
+* On imported shared libraries, the :prop_tgt:`IMPORTED_IMPLIB` target
+  property may now be used without :prop_tgt:`IMPORTED_LOCATION`.
+  This can be used to represent a stub library whose location should not
+  be added as a runtime search path to dependents that link it.