Xcode: Use "Link Binary With Libraries" build phase in some cases

OBJECT and STATIC libraries (framework or non-framework) do not use
this build phase. Not all items to be linked use this build phase either.

Co-Authored-By: Craig Scott <craig.scott@crascit.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/Help/prop_tgt/XCODE_LINK_BUILD_PHASE_MODE.rst b/Help/prop_tgt/XCODE_LINK_BUILD_PHASE_MODE.rst
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+XCODE_LINK_BUILD_PHASE_MODE
+---------------------------
+
+When using the :generator:`Xcode` generator, libraries to be linked will be
+specified in the Xcode project file using either the "Link Binary With
+Libraries" build phase or directly as linker flags.  The former allows Xcode
+to manage build paths, which may be necessary when creating Xcode archives
+because it may use different build paths to a regular build.
+
+This property controls usage of "Link Binary With Libraries" build phase for
+a target that is an app bundle, executable, shared library, shared framework
+or a module library.
+
+Possible values are:
+
+* ``NONE``
+  The libraries will be linked by specifying the linker flags directly.
+
+* ``BUILT_ONLY``
+  The "Link Binary With Libraries" build phase will be used to link to another
+  target under the following conditions:
+
+  - The target to be linked to is a regular non-imported, non-interface library
+    target.
+  - The output directory of the target being built has not been changed from
+    its default (see :prop_tgt:`RUNTIME_OUTPUT_DIRECTORY` and
+    :prop_tgt:`LIBRARY_OUTPUT_DIRECTORY`).
+
+* ``KNOWN_LOCATION``
+  The "Link Binary With Libraries" build phase will be used to link to another
+  target under the same conditions as with ``BUILT_ONLY`` and also:
+  - Imported library targets except those of type ``UNKNOWN``.
+  - Any non-target library specified directly with a path.
+
+For all other cases, the libraries will be linked by specifying the linker
+flags directly.
+
+.. warning::
+  Libraries linked using "Link Binary With Libraries" are linked after the
+  ones linked through regular linker flags.  This order should be taken into
+  account when different static libraries contain symbols with the same name,
+  as the former ones will take precedence over the latter.
+
+.. warning::
+  If two or more directories contain libraries with identical file names and
+  some libraries are linked from those directories, the library search path
+  lookup will end up linking libraries from the first directory.  This is a
+  known limitation of Xcode.
+
+This property is initialized by the value of the
+:variable:`CMAKE_XCODE_LINK_BUILD_PHASE_MODE` variable if it is set when a
+target is created.