diff --git a/libcxx/cmake/caches/Apple.cmake b/libcxx/cmake/caches/Apple.cmake
--- a/libcxx/cmake/caches/Apple.cmake
+++ b/libcxx/cmake/caches/Apple.cmake
@@ -18,3 +18,6 @@
 
 set(LIBCXXABI_ENABLE_ASSERTIONS OFF CACHE BOOL "")
 set(LIBCXXABI_ENABLE_FORGIVING_DYNAMIC_CAST ON CACHE BOOL "")
+
+set(LIBCXX_TEST_PARAMS "stdlib=apple-libc++" CACHE STRING "")
+set(LIBCXXABI_TEST_PARAMS "${LIBCXX_TEST_PARAMS}" CACHE STRING "")
diff --git a/libcxx/test/configs/legacy.cfg.in b/libcxx/test/configs/legacy.cfg.in
--- a/libcxx/test/configs/legacy.cfg.in
+++ b/libcxx/test/configs/legacy.cfg.in
@@ -8,6 +8,7 @@
 config.cxx_headers              = "@LIBCXX_GENERATED_INCLUDE_DIR@"
 config.cxx_under_test           = "@CMAKE_CXX_COMPILER@"
 config.project_obj_root         = "@CMAKE_BINARY_DIR@"
+config.install_root             = "@CMAKE_BINARY_DIR@"
 config.libcxx_src_root          = "@LIBCXX_SOURCE_DIR@"
 config.libcxx_obj_root          = "@LIBCXX_BINARY_DIR@"
 config.cxx_library_root         = "@LIBCXX_LIBRARY_DIR@"
diff --git a/libcxx/test/libcxx/vendor/apple/system-install-properties.sh.cpp b/libcxx/test/libcxx/vendor/apple/system-install-properties.sh.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/vendor/apple/system-install-properties.sh.cpp
@@ -0,0 +1,45 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: stdlib=apple-libc++
+
+// This file checks various properties of the installation of libc++ when built as
+// a system library on Apple platforms.
+//
+// TODO: We should install to `<prefix>/usr` in CMake and check that path instead.
+
+// Make sure we install the libc++ headers in the right location.
+//
+// RUN: stat "%{install}/include/c++/v1/__config"
+
+// Make sure we install libc++.1.dylib in the right location.
+//
+// RUN: stat "%{install}/lib/libc++.1.dylib"
+
+// Make sure we install a symlink from libc++.dylib to libc++.1.dylib.
+//
+// RUN: stat "%{install}/lib/libc++.dylib"
+// RUN: readlink "%{install}/lib/libc++.dylib" | grep "libc++.1.dylib"
+
+// Make sure the install_name is /usr/lib.
+//
+// In particular, make sure we don't use any @rpath in the load commands. When building as
+// a system library, it is important to hardcode the installation paths in the dylib, because
+// various tools like dyld and ld64 will treat us specially if they recognize us as being a
+// system library.
+//
+// TODO: We currently don't do that correctly in the CMake build.
+//
+// XRUNX: otool -L "%{install}/lib/libc++.1.dylib" | grep '/usr/lib/libc++.1.dylib'
+// XRUNX: ! otool -l "%{install}/lib/libc++.1.dylib" | grep -E "LC_RPATH|@loader_path|@rpath"
+
+// Make sure the compatibility_version of libc++ is 1.0.0.
+// Failure to respect this can result in applications not being able to find libc++
+// when they are loaded by dyld, if the compatibility version was bumped.
+//
+// RUN: otool -L "%{install}/lib/libc++.1.dylib" | grep "libc++.1.dylib" | grep "compatibility version 1.0.0"
diff --git a/libcxx/utils/libcxx/test/config.py b/libcxx/utils/libcxx/test/config.py
--- a/libcxx/utils/libcxx/test/config.py
+++ b/libcxx/utils/libcxx/test/config.py
@@ -467,6 +467,7 @@
         sub.append(('%{flags}',         ' '.join(map(self.quote, flags))))
         sub.append(('%{compile_flags}', ' '.join(map(self.quote, compile_flags))))
         sub.append(('%{link_flags}',    ' '.join(map(self.quote, self.cxx.link_flags))))
+        sub.append(('%{install}',       self.quote(self.config.install_root)))
 
         codesign_ident = self.get_lit_conf('llvm_codesign_identity', '')
         env_vars = ' '.join('%s=%s' % (k, self.quote(v)) for (k, v) in self.exec_env.items())
diff --git a/libcxx/utils/libcxx/test/params.py b/libcxx/utils/libcxx/test/params.py
--- a/libcxx/utils/libcxx/test/params.py
+++ b/libcxx/utils/libcxx/test/params.py
@@ -93,7 +93,7 @@
               AddCompileFlag('-fno-rtti')
             ]),
 
-  Parameter(name='stdlib', choices=['llvm-libc++', 'libstdc++', 'msvc'], type=str, default='llvm-libc++',
+  Parameter(name='stdlib', choices=['llvm-libc++', 'apple-libc++', 'libstdc++', 'msvc'], type=str, default='llvm-libc++',
             help="""The C++ Standard Library implementation being tested.
 
                  Note that this parameter can also be used to encode different 'flavors' of the same
@@ -102,6 +102,9 @@
 
                  The Standard libraries currently supported are:
                  - llvm-libc++: The 'upstream' libc++ as shipped with LLVM.
+                 - apple-libc++: libc++ as shipped by Apple. This is basically like the LLVM one, but
+                                 there are a few differences like installation paths and the use of
+                                 universal dylibs.
                  - libstdc++: The GNU C++ library typically shipped with GCC.
                  - msvc: The Microsoft implementation of the C++ Standard Library.
                 """,
diff --git a/libcxxabi/test/lit.site.cfg.in b/libcxxabi/test/lit.site.cfg.in
--- a/libcxxabi/test/lit.site.cfg.in
+++ b/libcxxabi/test/lit.site.cfg.in
@@ -7,6 +7,7 @@
 
 config.cxx_under_test           = "@CMAKE_CXX_COMPILER@"
 config.project_obj_root         = "@CMAKE_BINARY_DIR@"
+config.install_root             = "@CMAKE_BINARY_DIR@"
 config.libcxxabi_hdr_root       = "@LIBCXXABI_HEADER_DIR@"
 config.libcxxabi_src_root       = "@LIBCXXABI_SOURCE_DIR@"
 config.libcxxabi_obj_root       = "@LIBCXXABI_BINARY_DIR@"
diff --git a/libcxxabi/test/vendor/apple/system-install-properties.sh.cpp b/libcxxabi/test/vendor/apple/system-install-properties.sh.cpp
new file mode 100644
--- /dev/null
+++ b/libcxxabi/test/vendor/apple/system-install-properties.sh.cpp
@@ -0,0 +1,48 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: stdlib=apple-libc++
+
+// This file checks various properties of the installation of libc++abi when built
+// as a system library on Apple platforms.
+//
+// TODO: We should install to `<prefix>/usr` in CMake and check that path instead.
+
+// Make sure we install the libc++abi headers in the right location.
+// TODO: We don't currently install them, but we should.
+//
+// XRUNX: stat "%{install}/include/cxxabi.h"
+
+// Make sure we install libc++abi.dylib in the right location.
+//
+// RUN: stat "%{install}/lib/libc++abi.dylib"
+
+// Make sure we don't install a symlink from libc++abi.dylib to libc++abi.1.dylib,
+// unlike what we do for libc++.dylib.
+// TODO: We currently don't do that correctly in the CMake build.
+//
+// XRUNX: ! readlink "%{install}/lib/libc++abi.dylib"
+// XRUNX: ! stat "%{install}/lib/libc++abi.1.dylib"
+
+// Make sure the install_name is /usr/lib.
+//
+// In particular, make sure we don't use any @rpath in the load commands. When building as
+// a system library, it is important to hardcode the installation paths in the dylib, because
+// various tools like dyld and ld64 will treat us specially if they recognize us as being a
+// system library.
+//
+// TODO: We currently don't do that correctly in the CMake build.
+//
+// XRUNX: otool -L "%{install}/lib/libc++abi.dylib" | grep '/usr/lib/libc++abi.dylib'
+// XRUNX: ! otool -l "%{install}/lib/libc++abi.dylib" | grep -E "LC_RPATH|@loader_path|@rpath"
+
+// Make sure the compatibility_version of libc++abi is 1.0.0. Failure to respect this can result
+// in applications not being able to find libc++abi when they are loaded by dyld, if the
+// compatibility version was bumped.
+//
+// RUN: otool -L "%{install}/lib/libc++abi.dylib" | grep "libc++abi.1.dylib" | grep "compatibility version 1.0.0"
diff --git a/libunwind/test/lit.site.cfg.in b/libunwind/test/lit.site.cfg.in
--- a/libunwind/test/lit.site.cfg.in
+++ b/libunwind/test/lit.site.cfg.in
@@ -7,6 +7,7 @@
 
 config.cxx_under_test           = "@CMAKE_CXX_COMPILER@"
 config.project_obj_root         = "@CMAKE_BINARY_DIR@"
+config.install_root             = "@CMAKE_BINARY_DIR@"
 config.libunwind_src_root       = "@LIBUNWIND_SOURCE_DIR@"
 config.libunwind_obj_root       = "@LIBUNWIND_BINARY_DIR@"
 config.abi_library_root         = "@LIBUNWIND_LIBRARY_DIR@"