build: Fix Vulkan headers detection with CMake.
The logic used to find the location of the Vulkan headers and
registry used simple find_path() calls with HINTS. Unfortunately,
this doesn't work when using a custom toolchain file that sets
CMAKE_FIND_ROOT_PATH_INCLUDE to ONLY, which can happen when
cross-compiling with a custom sysroot.
This patch changes the logic so that:
- If VULKAN_HEADERS_INSTALL_DIR is specified on the command-line,
or if it is set in the environment, or if VULKAN_SDK is set in
the environment, the corresponding paths will be searched for
the Vulkan headers and register, ignoring the
CMAKE_FIND_ROOT_PATH. This does not affect other parts of the
build.
- Otherwise, use a regular find_path() call which may be restricted
to the CMAKE_FIND_ROOT_PATH depending on previous configuration
settings.
This should be equivalent to the previous behaviour, except when
CMAKE_FIND_ROOT_PATH_INCLUDE is set to ONLY.
diff --git a/cmake/FindVulkanHeaders.cmake b/cmake/FindVulkanHeaders.cmake
index 41afa9b..68e2611 100644
--- a/cmake/FindVulkanHeaders.cmake
+++ b/cmake/FindVulkanHeaders.cmake
@@ -45,21 +45,38 @@
# VulkanRegistry_DIR - the VulkanRegistry directory
#
-# Use HINTS instead of PATH to search these locations before
-# searching system environment variables like $PATH that may
-# contain SDK directories.
-find_path(VulkanHeaders_INCLUDE_DIR
- NAMES vulkan/vulkan.h
- HINTS
- ${VULKAN_HEADERS_INSTALL_DIR}/include
- "$ENV{VULKAN_HEADERS_INSTALL_DIR}/include"
- "$ENV{VULKAN_SDK}/include")
+# Probe command-line arguments and the environment to see if they specify the
+# Vulkan headers installation path.
+if(NOT DEFINED VULKAN_HEADERS_INSTALL_DIR)
+ if (DEFINED ENV{VULKAN_HEADERS_INSTALL_DIR})
+ set(VULKAN_HEADERS_INSTALL_DIR "$ENV{VULKAN_HEADERS_INSTALL_DIR}")
+ elseif(DEFINED ENV{VULKAN_SDK})
+ set(VULKAN_HEADERS_INSTALL_DIR "$ENV{VULKAN_SDK}/include")
+ endif()
+endif()
-if(VulkanHeaders_INCLUDE_DIR)
- get_filename_component(VULKAN_REGISTRY_PATH_HINT ${VulkanHeaders_INCLUDE_DIR} DIRECTORY)
- find_path(VulkanRegistry_DIR
- NAMES vk.xml
- HINTS "${VULKAN_REGISTRY_PATH_HINT}/share/vulkan/registry")
+if(DEFINED VULKAN_HEADERS_INSTALL_DIR)
+ # When CMAKE_FIND_ROOT_PATH_INCLUDE is set to ONLY, the HINTS in find_path()
+ # are re-rooted, which prevents VULKAN_HEADERS_INSTALL_DIR to work as
+ # expected. So use NO_CMAKE_FIND_ROOT_PATH to avoid it.
+
+ # Use HINTS instead of PATH to search these locations before
+ # searching system environment variables like $PATH that may
+ # contain SDK directories.
+ find_path(VulkanHeaders_INCLUDE_DIR
+ NAMES vulkan/vulkan.h
+ HINTS ${VULKAN_HEADERS_INSTALL_DIR}/include
+ NO_CMAKE_FIND_ROOT_PATH)
+ find_path(VulkanRegistry_DIR
+ NAMES vk.xml
+ HINTS ${VULKAN_HEADERS_INSTALL_DIR}/share/vulkan/registry
+ NO_CMAKE_FIND_ROOT_PATH)
+else()
+ # If VULKAN_HEADERS_INSTALL_DIR, or one of its variants was not specified,
+ # do a normal search without hints.
+ find_path(VulkanHeaders_INCLUDE_DIR NAMES vulkan/vulkan.h)
+ get_filename_component(VULKAN_REGISTRY_PATH_HINT ${VulkanHeaders_INCLUDE_DIR} DIRECTORY)
+ find_path(VulkanRegistry_DIR NAMES vk.xml HINTS ${VULKAN_REGISTRY_PATH_HINT})
endif()
set(VulkanHeaders_INCLUDE_DIRS ${VulkanHeaders_INCLUDE_DIR})
