Merge remote-tracking branch 'upstream/main'

tests/add_subdirectory/CMakeLists.txt

@@ -0,0 +1,30 @@
+# ~~~
+# Copyright 2022-2023 The Khronos Group Inc.
+# Copyright 2022-2023 Valve Corporation
+# Copyright 2022-2023 LunarG, Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+# ~~~
+cmake_minimum_required(VERSION 3.14.2)
+
+project(TEST_VULKAN_HEADERS_ADD_SUBDIRECTORY_SUPPORT LANGUAGES C)
+
+add_subdirectory(../../ ${CMAKE_CURRENT_BINARY_DIR}/headers)
+
+if (NOT TARGET Vulkan::Headers)
+    message(FATAL_ERROR "Vulkan::Headers target not defined")
+endif()
+
+# Consuming vulkan-headers via add_subdirectory should NOT add installation code to the parent CMake project.
+if (DEFINED CMAKE_INSTALL_INCLUDEDIR)
+    message(FATAL_ERROR "CMAKE_INSTALL_INCLUDEDIR was defined!")
+endif()
+
+add_library(foobar STATIC)
+
+target_link_libraries(foobar PRIVATE Vulkan::Headers)
+
+target_sources(foobar PRIVATE
+    ../vk_icd.c
+    ../vk_layer.c
+)