add_library: mention that Xcode requires a real source file

The docs mentioned that it happened, but not when. Mention Xcode since
it is the culprit today.

See #16524.
This commit is contained in:
Ben Boeckel
2017-12-01 10:36:01 -05:00
parent a4faf86387
commit 4c40ab261c

View File

@@ -111,9 +111,9 @@ may contain only sources that compile, header files, and other files
that would not affect linking of a normal library (e.g. ``.txt``).
They may contain custom commands generating such sources, but not
``PRE_BUILD``, ``PRE_LINK``, or ``POST_BUILD`` commands. Object libraries
cannot be linked. Some native build systems may not like targets that
have only object files, so consider adding at least one real source file
to any target that references ``$<TARGET_OBJECTS:objlib>``.
cannot be linked. Some native build systems (such as Xcode) may not like
targets that have only object files, so consider adding at least one real
source file to any target that references ``$<TARGET_OBJECTS:objlib>``.
Alias Libraries
^^^^^^^^^^^^^^^