Xcode: Do not append per-config suffixes to library search paths

Add policy `CMP0142` to remove the automatic addition of the
`$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)` suffix in a compatible way.

Fixes: #21757

1 files changed, 27 insertions, 0 deletions

diff --git a/Help/policy/CMP0142.rst b/Help/policy/CMP0142.rst
new file mode 100644
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+++ b/Help/policy/CMP0142.rst
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+CMP0142
+-------
+
+.. versionadded:: 3.25
+
+The :generator:`Xcode` generator does not append per-config suffixes to
+library search paths.
+
+In CMake 3.24 and below, the :generator:`Xcode` generator preceded each
+entry of a library search path with a copy of itself appended with
+``$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)``.  This was left from
+very early versions of CMake in which per-config directories were not well
+modeled.  Such paths often do not exist, resulting in warnings from the
+toolchain.  CMake 3.25 and above prefer to not add such library search
+paths.  This policy provides compatibility for projects that may have been
+accidentally relying on the old behavior.
+
+The ``OLD`` behavior for this policy is to append
+``$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)`` to all library search paths.
+The ``NEW`` behavior is to not modify library search paths.
+
+This policy was introduced in CMake version 3.25.  Use the
+:command:`cmake_policy` command to set it to ``OLD`` or ``NEW`` explicitly.
+Unlike many policies, CMake version |release| does *not* warn
+when this policy is not set and simply uses ``OLD`` behavior.
+
+.. include:: DEPRECATED.txt