loader.c

/*
 *
 * Copyright (c) 2014-2023 The Khronos Group Inc.
 * Copyright (c) 2014-2023 Valve Corporation
 * Copyright (c) 2014-2023 LunarG, Inc.
 * Copyright (C) 2015 Google Inc.
 * Copyright (c) 2021-2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * Copyright (c) 2023-2023 RasterGrid Kft.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.

 *
 * Author: Jon Ashburn <jon@lunarg.com>
 * Author: Courtney Goeltzenleuchter <courtney@LunarG.com>
 * Author: Mark Young <marky@lunarg.com>
 * Author: Lenny Komow <lenny@lunarg.com>
 * Author: Charles Giessen <charles@lunarg.com>
 *
 */

#include "loader.h"

#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <stdbool.h>
#include <string.h>
#include <stddef.h>

#if defined(__APPLE__)
#include <CoreFoundation/CoreFoundation.h>
#include <sys/param.h>
#endif

#include <sys/types.h>
#if defined(_WIN32)
#include "dirent_on_windows.h"
#elif COMMON_UNIX_PLATFORMS
#include <dirent.h>
#else
#warning dirent.h not available on this platform
#endif // _WIN32

#include "allocation.h"
#include "stack_allocation.h"
#include "cJSON.h"
#include "debug_utils.h"
#include "loader_environment.h"
#include "loader_json.h"
#include "log.h"
#include "unknown_function_handling.h"
#include "vk_loader_platform.h"
#include "wsi.h"

#if defined(WIN32)
#include "loader_windows.h"
#endif
#if defined(LOADER_ENABLE_LINUX_SORT)
// This header is currently only used when sorting Linux devices, so don't include it otherwise.
#include "loader_linux.h"
#endif // LOADER_ENABLE_LINUX_SORT

// Generated file containing all the extension data
#include "vk_loader_extensions.c"

struct loader_struct loader = {0};

struct activated_layer_info {
 char *name;
 char *manifest;
 char *library;
 bool is_implicit;
 enum loader_layer_enabled_by_what enabled_by_what;
 char *disable_env;
 char *enable_name_env;
 char *enable_value_env;
};

// thread safety lock for accessing global data structures such as "loader"
// all entrypoints on the instance chain need to be locked except GPA
// additionally CreateDevice and DestroyDevice needs to be locked
loader_platform_thread_mutex loader_lock;
loader_platform_thread_mutex loader_preload_icd_lock;

// A list of ICDs that gets initialized when the loader does its global initialization. This list should never be used by anything
// other than EnumerateInstanceExtensionProperties(), vkDestroyInstance, and loader_release(). This list does not change
// functionality, but the fact that the libraries already been loaded causes any call that needs to load ICD libraries to speed up
// significantly. This can have a huge impact when making repeated calls to vkEnumerateInstanceExtensionProperties and
// vkCreateInstance.
struct loader_icd_tramp_list preloaded_icds;

// controls whether loader_platform_close_library() closes the libraries or not - controlled by an environment
// variables - this is just the definition of the variable, usage is in vk_loader_platform.h
bool loader_disable_dynamic_library_unloading;

LOADER_PLATFORM_THREAD_ONCE_DECLARATION(once_init);

// Creates loader_api_version struct that contains the major and minor fields, setting patch to 0
loader_api_version loader_make_version(uint32_t version) {
 loader_api_version out_version;
 out_version.major = VK_API_VERSION_MAJOR(version);
 out_version.minor = VK_API_VERSION_MINOR(version);
 out_version.patch = 0;
 return out_version;
}

// Creates loader_api_version struct containing the major, minor, and patch fields
loader_api_version loader_make_full_version(uint32_t version) {
 loader_api_version out_version;
 out_version.major = VK_API_VERSION_MAJOR(version);
 out_version.minor = VK_API_VERSION_MINOR(version);
 out_version.patch = VK_API_VERSION_PATCH(version);
 return out_version;
}

loader_api_version loader_combine_version(uint32_t major, uint32_t minor, uint32_t patch) {
 loader_api_version out_version;
 out_version.major = (uint16_t)major;
 out_version.minor = (uint16_t)minor;
 out_version.patch = (uint16_t)patch;
 return out_version;
}

// Helper macros for determining if a version is valid or not
bool loader_check_version_meets_required(loader_api_version required, loader_api_version version) {
 // major version is satisfied
 return (version.major > required.major) ||
 // major version is equal, minor version is patch version is greater to minimum minor
 (version.major == required.major && version.minor > required.minor) ||
 // major and minor version are equal, patch version is greater or equal to minimum patch
 (version.major == required.major && version.minor == required.minor && version.patch >= required.patch);
}

const char *get_enabled_by_what_str(enum loader_layer_enabled_by_what enabled_by_what) {
 switch (enabled_by_what) {
 default:
 assert(true && "Shouldn't reach this");
 return "Unknown";
 case (ENABLED_BY_WHAT_UNSET):
 assert(true && "Shouldn't reach this");
 return "Unknown";
 case (ENABLED_BY_WHAT_LOADER_SETTINGS_FILE):
 return "Loader Settings File (Vulkan Configurator)";
 case (ENABLED_BY_WHAT_IMPLICIT_LAYER):
 return "Implicit Layer";
 case (ENABLED_BY_WHAT_VK_INSTANCE_LAYERS):
 return "Environment Variable VK_INSTANCE_LAYERS";
 case (ENABLED_BY_WHAT_VK_LOADER_LAYERS_ENABLE):
 return "Environment Variable VK_LOADER_LAYERS_ENABLE";
 case (ENABLED_BY_WHAT_IN_APPLICATION_API):
 return "By the Application";
 case (ENABLED_BY_WHAT_META_LAYER):
 return "Meta Layer (Vulkan Configurator)";
 }
}

// Wrapper around opendir so that the dirent_on_windows gets the instance it needs
// while linux opendir & readdir does not
DIR *loader_opendir(const struct loader_instance *instance, const char *name) {
#if defined(_WIN32)
 return opendir(instance ? &instance->alloc_callbacks : NULL, name);
#elif COMMON_UNIX_PLATFORMS
 (void)instance;
 return opendir(name);
#else
#warning dirent.h - opendir not available on this platform
#endif // _WIN32
}
int loader_closedir(const struct loader_instance *instance, DIR *dir) {
#if defined(_WIN32)
 return closedir(instance ? &instance->alloc_callbacks : NULL, dir);
#elif COMMON_UNIX_PLATFORMS
 (void)instance;
 return closedir(dir);
#else
#warning dirent.h - closedir not available on this platform
#endif // _WIN32
}

bool is_json(const char *path, size_t len) {
 if (len < 5) {
 return false;
 }
 return !strncmp(path + len - 5, ".json", 5);
}

// Handle error from to library loading
void loader_handle_load_library_error(const struct loader_instance *inst, const char *filename,
 enum loader_layer_library_status *lib_status) {
 const char *error_message = loader_platform_open_library_error(filename);
 // If the error is due to incompatible architecture (eg 32 bit vs 64 bit), report it with INFO level
 // Discussed in Github issue 262 & 644
 // "wrong ELF class" is a linux error, " with error 193" is a windows error
 VkFlags err_flag = VULKAN_LOADER_ERROR_BIT;
 if (strstr(error_message, "wrong ELF class:") != NULL || strstr(error_message, " with error 193") != NULL) {
 err_flag = VULKAN_LOADER_INFO_BIT;
 if (NULL != lib_status) {
 *lib_status = LOADER_LAYER_LIB_ERROR_WRONG_BIT_TYPE;
 }
 }
 // Check if the error is due to lack of memory
 // "with error 8" is the windows error code for OOM cases, aka ERROR_NOT_ENOUGH_MEMORY
 // Linux doesn't have such a nice error message - only if there are reported issues should this be called
 else if (strstr(error_message, " with error 8") != NULL) {
 if (NULL != lib_status) {
 *lib_status = LOADER_LAYER_LIB_ERROR_OUT_OF_MEMORY;
 }
 } else if (NULL != lib_status) {
 *lib_status = LOADER_LAYER_LIB_ERROR_FAILED_TO_LOAD;
 }
 loader_log(inst, err_flag, 0, "%s", error_message);
}

VKAPI_ATTR VkResult VKAPI_CALL vkSetInstanceDispatch(VkInstance instance, void *object) {
 struct loader_instance *inst = loader_get_instance(instance);
 if (!inst) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "vkSetInstanceDispatch: Can not retrieve Instance dispatch table.");
 return VK_ERROR_INITIALIZATION_FAILED;
 }
 loader_set_dispatch(object, inst->disp);
 return VK_SUCCESS;
}

VKAPI_ATTR VkResult VKAPI_CALL vkSetDeviceDispatch(VkDevice device, void *object) {
 struct loader_device *dev;
 struct loader_icd_term *icd_term = loader_get_icd_and_device(device, &dev);

 if (NULL == icd_term || NULL == dev) {
 return VK_ERROR_INITIALIZATION_FAILED;
 }
 loader_set_dispatch(object, &dev->loader_dispatch);
 return VK_SUCCESS;
}

void loader_free_layer_properties(const struct loader_instance *inst, struct loader_layer_properties *layer_properties) {
 loader_instance_heap_free(inst, layer_properties->manifest_file_name);
 loader_instance_heap_free(inst, layer_properties->lib_name);
 loader_instance_heap_free(inst, layer_properties->functions.str_gipa);
 loader_instance_heap_free(inst, layer_properties->functions.str_gdpa);
 loader_instance_heap_free(inst, layer_properties->functions.str_negotiate_interface);
 loader_destroy_generic_list(inst, (struct loader_generic_list *)&layer_properties->instance_extension_list);
 if (layer_properties->device_extension_list.capacity > 0 && NULL != layer_properties->device_extension_list.list) {
 for (uint32_t i = 0; i < layer_properties->device_extension_list.count; i++) {
 free_string_list(inst, &layer_properties->device_extension_list.list[i].entrypoints);
 }
 }
 loader_destroy_generic_list(inst, (struct loader_generic_list *)&layer_properties->device_extension_list);
 loader_instance_heap_free(inst, layer_properties->disable_env_var.name);
 loader_instance_heap_free(inst, layer_properties->disable_env_var.value);
 loader_instance_heap_free(inst, layer_properties->enable_env_var.name);
 loader_instance_heap_free(inst, layer_properties->enable_env_var.value);
 free_string_list(inst, &layer_properties->component_layer_names);
 loader_instance_heap_free(inst, layer_properties->pre_instance_functions.enumerate_instance_extension_properties);
 loader_instance_heap_free(inst, layer_properties->pre_instance_functions.enumerate_instance_layer_properties);
 loader_instance_heap_free(inst, layer_properties->pre_instance_functions.enumerate_instance_version);
 free_string_list(inst, &layer_properties->override_paths);
 free_string_list(inst, &layer_properties->blacklist_layer_names);
 free_string_list(inst, &layer_properties->app_key_paths);

 // Make sure to clear out the removed layer, in case new layers are added in the previous location
 memset(layer_properties, 0, sizeof(struct loader_layer_properties));
}

VkResult loader_init_library_list(struct loader_layer_list *instance_layers, loader_platform_dl_handle **libs) {
 if (instance_layers->count > 0) {
 *libs = loader_calloc(NULL, sizeof(loader_platform_dl_handle) * instance_layers->count, VK_SYSTEM_ALLOCATION_SCOPE_COMMAND);
 if (*libs == NULL) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 }
 return VK_SUCCESS;
}

bool is_string_in_string_list(struct loader_string_list *string_list, const char *str) {
 // Remove duplicate paths, or it would result in duplicate extensions, duplicate devices, etc.
 for (size_t i = 0; i < string_list->count; i++) {
 if (strcmp(string_list->list[i], str) == 0) {
 return true;
 }
 }
 return false;
}

VkResult loader_copy_to_new_str(const struct loader_instance *inst, const char *source_str, char **dest_str) {
 assert(source_str && dest_str);
 size_t str_len = strlen(source_str) + 1;
 *dest_str = loader_instance_heap_calloc(inst, str_len, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == *dest_str) return VK_ERROR_OUT_OF_HOST_MEMORY;
 loader_strncpy(*dest_str, str_len, source_str, str_len);
 (*dest_str)[str_len - 1] = 0;
 return VK_SUCCESS;
}

VkResult create_string_list(const struct loader_instance *inst, uint32_t allocated_count, struct loader_string_list *string_list) {
 assert(string_list);
 string_list->list = loader_instance_heap_calloc(inst, sizeof(char *) * allocated_count, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == string_list->list) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 string_list->allocated_count = allocated_count;
 string_list->count = 0;
 return VK_SUCCESS;
}

VkResult increase_str_capacity_by_at_least_one(const struct loader_instance *inst, struct loader_string_list *string_list) {
 assert(string_list);
 if (string_list->allocated_count == 0) {
 string_list->allocated_count = 32;
 string_list->list =
 loader_instance_heap_calloc(inst, sizeof(char *) * string_list->allocated_count, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == string_list->list) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 } else if (string_list->count + 1 > string_list->allocated_count) {
 uint32_t new_allocated_count = string_list->allocated_count * 2;
 void *new_ptr = loader_instance_heap_realloc(inst, string_list->list, sizeof(char *) * string_list->allocated_count,
 sizeof(char *) * new_allocated_count, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_ptr) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 string_list->list = new_ptr;
 string_list->allocated_count *= 2;
 }
 return VK_SUCCESS;
}

VkResult append_str_to_string_list(const struct loader_instance *inst, struct loader_string_list *string_list, char *str) {
 assert(string_list && str);
 VkResult res = increase_str_capacity_by_at_least_one(inst, string_list);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 loader_instance_heap_free(inst, str); // Must clean up in case of failure
 return res;
 }
 string_list->list[string_list->count++] = str;
 return VK_SUCCESS;
}

VkResult append_str_to_string_list_if_unique(const struct loader_instance *inst, struct loader_string_list *string_list,
 char *str) {
 if (is_string_in_string_list(string_list, str)) {
 // Since this string is a duplicate and this function takes ownership, we need to free it.
 loader_instance_heap_free(inst, str);
 return VK_SUCCESS;
 }
 return append_str_to_string_list(inst, string_list, str);
}

VkResult prepend_str_to_string_list(const struct loader_instance *inst, struct loader_string_list *string_list, char *str) {
 assert(string_list && str);
 VkResult res = increase_str_capacity_by_at_least_one(inst, string_list);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 loader_instance_heap_free(inst, str); // Must clean up in case of failure
 return res;
 }
 // Shift everything down one
 void *ptr_to_list = memmove(string_list->list + 1, string_list->list, sizeof(char *) * string_list->count);
 if (ptr_to_list) string_list->list[0] = str; // Write new string to start of list
 string_list->count++;
 return VK_SUCCESS;
}

VkResult copy_str_to_string_list(const struct loader_instance *inst, struct loader_string_list *string_list, const char *str,
 size_t str_len) {
 assert(string_list && str);
 char *new_str = loader_instance_heap_calloc(inst, str_len + 1, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_str) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 loader_strncpy(new_str, str_len + 1, str, str_len);
 new_str[str_len] = '\0';
 return append_str_to_string_list(inst, string_list, new_str);
}

VkResult copy_str_to_string_list_if_unique(const struct loader_instance *inst, struct loader_string_list *string_list,
 const char *str, size_t str_len) {
 if (is_string_in_string_list(string_list, str)) {
 return VK_SUCCESS;
 }
 return copy_str_to_string_list(inst, string_list, str, str_len);
}

VkResult copy_str_to_start_of_string_list(const struct loader_instance *inst, struct loader_string_list *string_list,
 const char *str, size_t str_len) {
 assert(string_list && str);
 char *new_str = loader_instance_heap_calloc(inst, str_len + 1, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_str) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 loader_strncpy(new_str, str_len + 1, str, str_len);
 new_str[str_len] = '\0';
 return prepend_str_to_string_list(inst, string_list, new_str);
}

void free_string_list(const struct loader_instance *inst, struct loader_string_list *string_list) {
 assert(string_list);
 if (string_list->list) {
 for (uint32_t i = 0; i < string_list->count; i++) {
 loader_instance_heap_free(inst, string_list->list[i]);
 string_list->list[i] = NULL;
 }
 loader_instance_heap_free(inst, string_list->list);
 }
 memset(string_list, 0, sizeof(struct loader_string_list));
}

// In place modify the passed in path to do the following:
// If HAVE_REALPATH is defined, then this simply calls realpath() so its behavior is defined by realpath()
// Else:
// * Windows-only: Replace forward slashes with backwards slashes (platform correct directory separator)
// * Replace contiguous directory separators with a single directory separator
// * Replace "/./" separator with "/" (where / is the platform correct directory separator)
// * Replace "/<directory_name>/../" with just "/" (where / is the platform correct directory separator)
VkResult normalize_path(const struct loader_instance *inst, char **passed_in_path) {
 // passed_in_path doesn't point to anything, can't modify inplace so just return
 if (passed_in_path == NULL) {
 return VK_SUCCESS;
 }

// POSIX systems has the realpath() function to do this for us, fallback to basic normalization on other platforms
#if defined(HAVE_REALPATH)
 char *path = loader_instance_heap_calloc(inst, PATH_MAX, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == path) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 char *ret = realpath(*passed_in_path, path);
 if (NULL == ret) {
 // error path
 int error_code = errno;
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "normalize_path: Call to realpath() failed with error code %d when given the path %s", error_code,
 *passed_in_path);
 loader_instance_heap_free(inst, path);
 } else {
 // Replace string pointed to by passed_in_path with the one given to us by realpath()
 loader_instance_heap_free(inst, *passed_in_path);
 *passed_in_path = path;
 }
 return VK_SUCCESS;

// Windows has GetFullPathName which does essentially the same thing. Note that we call GetFullPathNameA because the path has
// already been converted from the wide char format when it was initially gotten
#elif defined(WIN32)
 VkResult res = VK_SUCCESS;
 DWORD path_len = (DWORD)strlen(*passed_in_path) + 1;
 char *path = loader_instance_heap_calloc(inst, (size_t)path_len, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == path) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 DWORD actual_len = GetFullPathNameA(*passed_in_path, path_len, path, NULL);
 if (actual_len == 0) {
 size_t last_error = (size_t)GetLastError();
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "normalize_path: Call to GetFullPathNameA() failed with error code %zu when given the path %s", last_error,
 *passed_in_path);
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // If path_len wasn't big enough, need to realloc and call again
 // actual_len doesn't include null terminator
 if (actual_len + 1 > path_len) {
 char *new_path = loader_instance_heap_realloc(inst, path, path_len, actual_len + 1, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_path) {
 loader_instance_heap_free(inst, path);
 path = NULL;
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 path = new_path;
 // store the updated allocation size (sans null terminator)
 path_len = actual_len + 1;

 actual_len = GetFullPathNameA(*passed_in_path, path_len, path, NULL);
 if (actual_len == 0) {
 size_t last_error = (size_t)GetLastError();
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "normalize_path: Call to GetFullPathNameA() failed with error code %zu when given the path %s", last_error,
 *passed_in_path);
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 // actual_len doesn't include null terminator
 } else if (actual_len + 1 != path_len) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "normalize_path: Call to GetFullPathNameA() with too small of a buffer when given the path %s after the "
 "initial call to GetFullPathNameA() failed for the same reason. Buffer size is %zu, actual size is %zu",
 *passed_in_path, (size_t)path_len, (size_t)actual_len);
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 }
 // Replace string pointed to by passed_in_path with the one given to us by realpath()
 loader_instance_heap_free(inst, *passed_in_path);
 *passed_in_path = path;
out:
 if (VK_SUCCESS != res) {
 if (NULL != path) {
 loader_instance_heap_free(inst, path);
 }
 }
 return res;

#else
 (void)inst;
 char *path = *passed_in_path;
 size_t path_len = strlen(path) + 1;

 size_t output_index = 0;
 // Iterate through the string up to the last character, excluding the null terminator
 for (size_t i = 0; i < path_len - 1; i++) {
 if (i + 1 < path_len && path[i] == DIRECTORY_SYMBOL && path[i + 1] == DIRECTORY_SYMBOL) {
 continue;
 } else if (i + 2 < path_len && path[i] == DIRECTORY_SYMBOL && path[i + 1] == '.' && path[i + 2] == DIRECTORY_SYMBOL) {
 i += 1;
 } else {
 path[output_index++] = path[i];
 }
 }
 // Add null terminator and set the new length
 path[output_index++] = '\0';
 path_len = output_index;

 // Loop while there are still ..'s in the path. Easiest implementation resolves them one by one, which requires quadratic
 // iteration through the string
 char *directory_stack = loader_stack_alloc(path_len);
 if (directory_stack == NULL) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 size_t top_of_stack = 0;

 // Iterate through the path, push characters as we see them, if we find a "..", pop off the top of the directory stack until the
 // current directory is gone.
 for (size_t i = 0; i < path_len - 1; i++) {
 // if the next part of path is "/../" we need to pop from the directory stack until we hit the previous directory symbol.
 if (i + 3 < path_len && path[i] == DIRECTORY_SYMBOL && path[i + 1] == '.' && path[i + 2] == '.' && path_len &&
 path[i + 3] == DIRECTORY_SYMBOL) {
 // Pop until we hit the next directory symbol in the stack
 while (top_of_stack > 0 && directory_stack[top_of_stack - 1] != DIRECTORY_SYMBOL) {
 top_of_stack--;
 directory_stack[top_of_stack] = '\0';
 }
 // Amend the directory stack so that the top isn't a directory separator
 if (top_of_stack > 0 && directory_stack[top_of_stack - 1] == DIRECTORY_SYMBOL) {
 top_of_stack--;
 directory_stack[top_of_stack] = '\0';
 }
 i += 2; // need to skip the second dot & directory separator
 } else {
 // push characters as we come across them
 directory_stack[top_of_stack++] = path[i];
 }
 }

 // Can't forget the null terminator
 directory_stack[top_of_stack] = '\0';

 // We now have the path without any ..'s, so just copy it out
 loader_strncpy(path, path_len, directory_stack, path_len);
 path[top_of_stack] = '\0';
 path_len = top_of_stack + 1;

 return VK_SUCCESS;
#endif
}

// Queries the path to the library that lib_handle & gipa are associated with, allocating a string to hold it and returning it in
// out_path
VkResult get_library_path_of_dl_handle(const struct loader_instance *inst, loader_platform_dl_handle lib_handle,
 PFN_vkGetInstanceProcAddr gipa, char **out_path) {
#if COMMON_UNIX_PLATFORMS
 (void)lib_handle;
 Dl_info dl_info = {0};
 if (dladdr(gipa, &dl_info) != 0 && NULL != dl_info.dli_fname) {
 return loader_copy_to_new_str(inst, dl_info.dli_fname, out_path);
 }
 return VK_SUCCESS;

#elif defined(WIN32)
 (void)gipa;
 size_t module_file_name_len = MAX_PATH; // start with reasonably large buffer
 wchar_t *buffer_utf16 = (wchar_t *)loader_stack_alloc(module_file_name_len * sizeof(wchar_t));
 DWORD ret = GetModuleFileNameW(lib_handle, buffer_utf16, (DWORD)module_file_name_len);
 if (ret == 0) {
 return VK_SUCCESS;
 }
 while (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
 module_file_name_len *= 2;
 buffer_utf16 = (wchar_t *)loader_stack_alloc(module_file_name_len * sizeof(wchar_t));
 ret = GetModuleFileNameW(lib_handle, buffer_utf16, (DWORD)module_file_name_len);
 if (ret == 0) {
 return VK_SUCCESS;
 }
 }

 // Need to convert from utf16 to utf8
 int buffer_utf8_size = WideCharToMultiByte(CP_UTF8, 0, buffer_utf16, -1, NULL, 0, NULL, NULL);
 if (buffer_utf8_size <= 0) {
 return VK_SUCCESS;
 }

 char *buffer_utf8 = loader_instance_heap_calloc(inst, buffer_utf8_size, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == buffer_utf8) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 if (WideCharToMultiByte(CP_UTF8, 0, buffer_utf16, -1, buffer_utf8, buffer_utf8_size, NULL, NULL) != buffer_utf8_size) {
 return VK_SUCCESS;
 }

 // Successfully got the 'real' path to the library.
 *out_path = buffer_utf8;
 return VK_SUCCESS;

#else
 // Do nothing, platform doesn't handle getting the path to a library
#endif
}

// Find and replace the path that was loaded using the lib_name path with the real path of the library. This is done to provide
// accurate logging info for users.
// This function prints a warning if there is a mismatch between the lib_name path and the real path.
VkResult fixup_library_binary_path(const struct loader_instance *inst, char **lib_name, loader_platform_dl_handle lib_handle,
 PFN_vkGetInstanceProcAddr gipa) {
 if (lib_name == NULL) {
 // do nothing as we got an invalid lib_path pointer
 return VK_SUCCESS;
 }

 bool system_path = true;
 size_t lib_name_len = strlen(*lib_name) + 1;
 for (size_t i = 0; i < lib_name_len; i++) {
 if ((*lib_name)[i] == DIRECTORY_SYMBOL) {
 system_path = false;
 break;
 }
 }

 if (!system_path) {
 // The OS path we get for a binary is normalized, so we need to normalize the path passed into LoadLibrary/dlopen so that
 // mismatches are minimized. EG, do not warn when we give dlopen/LoadLibrary "/foo/./bar" but get "/foo/bar" as the loaded
 // binary path from the OS.
 VkResult res = normalize_path(inst, lib_name);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }
 }
 char *os_determined_lib_name = NULL;
 VkResult res = get_library_path_of_dl_handle(inst, lib_handle, gipa, &os_determined_lib_name);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }

 if (NULL != os_determined_lib_name) {
 // Normalize the path so that the comparison doesn't yield false positives
 res = normalize_path(inst, &os_determined_lib_name);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 loader_instance_heap_free(inst, os_determined_lib_name);
 return res;
 }

 if (0 != strcmp(os_determined_lib_name, *lib_name)) {
 // Paths do not match, so we need to replace lib_name with the real path
 if (!system_path) {
 // Only warn when the library_path is relative or absolute, not system. EG lib_name had no directory separators
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Path to given binary %s was found to differ from OS loaded path %s", *lib_name, os_determined_lib_name);
 }
 loader_instance_heap_free(inst, *lib_name);
 *lib_name = os_determined_lib_name;
 } else {
 // Paths match, so just need to free temporary allocation
 loader_instance_heap_free(inst, os_determined_lib_name);
 }
 }

 return res;
}

// Given string of three part form "maj.min.pat" convert to a vulkan version number.
// Also can understand four part form "variant.major.minor.patch" if provided.
uint32_t loader_parse_version_string(char *vers_str) {
 uint32_t variant = 0, major = 0, minor = 0, patch = 0;
 char *vers_tok;
 char *context = NULL;
 if (!vers_str) {
 return 0;
 }

 vers_tok = thread_safe_strtok(vers_str, ".\"\n\r", &context);
 if (NULL != vers_tok) {
 major = (uint16_t)atoi(vers_tok);
 vers_tok = thread_safe_strtok(NULL, ".\"\n\r", &context);
 if (NULL != vers_tok) {
 minor = (uint16_t)atoi(vers_tok);
 vers_tok = thread_safe_strtok(NULL, ".\"\n\r", &context);
 if (NULL != vers_tok) {
 patch = (uint16_t)atoi(vers_tok);
 vers_tok = thread_safe_strtok(NULL, ".\"\n\r", &context);
 // check that we are using a 4 part version string
 if (NULL != vers_tok) {
 // if we are, move the values over into the correct place
 variant = major;
 major = minor;
 minor = patch;
 patch = (uint16_t)atoi(vers_tok);
 }
 }
 }
 }

 return VK_MAKE_API_VERSION(variant, major, minor, patch);
}

bool compare_vk_extension_properties(const VkExtensionProperties *op1, const VkExtensionProperties *op2) {
 return strcmp(op1->extensionName, op2->extensionName) == 0 ? true : false;
}

// Search the given ext_array for an extension matching the given vk_ext_prop
bool has_vk_extension_property_array(const VkExtensionProperties *vk_ext_prop, const uint32_t count,
 const VkExtensionProperties *ext_array) {
 for (uint32_t i = 0; i < count; i++) {
 if (compare_vk_extension_properties(vk_ext_prop, &ext_array[i])) return true;
 }
 return false;
}

// Search the given ext_list for an extension matching the given vk_ext_prop
bool has_vk_extension_property(const VkExtensionProperties *vk_ext_prop, const struct loader_extension_list *ext_list) {
 for (uint32_t i = 0; i < ext_list->count; i++) {
 if (compare_vk_extension_properties(&ext_list->list[i], vk_ext_prop)) return true;
 }
 return false;
}

// Search the given ext_list for a device extension matching the given ext_prop
bool has_vk_dev_ext_property(const VkExtensionProperties *ext_prop, const struct loader_device_extension_list *ext_list) {
 for (uint32_t i = 0; i < ext_list->count; i++) {
 if (compare_vk_extension_properties(&ext_list->list[i].props, ext_prop)) return true;
 }
 return false;
}

VkResult loader_append_layer_property(const struct loader_instance *inst, struct loader_layer_list *layer_list,
 struct loader_layer_properties *layer_property) {
 VkResult res = VK_SUCCESS;
 if (layer_list->capacity == 0) {
 res = loader_init_generic_list(inst, (struct loader_generic_list *)layer_list, sizeof(struct loader_layer_properties));
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 // Ensure enough room to add an entry
 if ((layer_list->count + 1) * sizeof(struct loader_layer_properties) > layer_list->capacity) {
 void *new_ptr = loader_instance_heap_realloc(inst, layer_list->list, layer_list->capacity, layer_list->capacity * 2,
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_ptr) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_append_layer_property: realloc failed for layer list");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 layer_list->list = new_ptr;
 layer_list->capacity *= 2;
 }
 memcpy(&layer_list->list[layer_list->count], layer_property, sizeof(struct loader_layer_properties));
 layer_list->count++;
 memset(layer_property, 0, sizeof(struct loader_layer_properties));
out:
 if (res != VK_SUCCESS) {
 loader_free_layer_properties(inst, layer_property);
 }
 return res;
}

// Search the given layer list for a layer property matching the given layer name
struct loader_layer_properties *loader_find_layer_property(const char *name, const struct loader_layer_list *layer_list) {
 for (uint32_t i = 0; i < layer_list->count; i++) {
 const VkLayerProperties *item = &layer_list->list[i].info;
 if (strcmp(name, item->layerName) == 0) return &layer_list->list[i];
 }
 return NULL;
}

struct loader_layer_properties *loader_find_pointer_layer_property(const char *name,
 const struct loader_pointer_layer_list *layer_list) {
 for (uint32_t i = 0; i < layer_list->count; i++) {
 const VkLayerProperties *item = &layer_list->list[i]->info;
 if (strcmp(name, item->layerName) == 0) return layer_list->list[i];
 }
 return NULL;
}

// Search the given layer list for a layer matching the given layer name
bool loader_find_layer_name_in_list(const char *name, const struct loader_pointer_layer_list *layer_list) {
 if (NULL == layer_list) {
 return false;
 }
 if (NULL != loader_find_pointer_layer_property(name, layer_list)) {
 return true;
 }
 return false;
}

// Search the override layer's blacklist for a layer matching the given layer name
bool loader_find_layer_name_in_blacklist(const char *layer_name, struct loader_layer_properties *meta_layer_props) {
 for (uint32_t black_layer = 0; black_layer < meta_layer_props->blacklist_layer_names.count; ++black_layer) {
 if (!strcmp(meta_layer_props->blacklist_layer_names.list[black_layer], layer_name)) {
 return true;
 }
 }
 return false;
}

// Remove all layer properties entries from the list
TEST_FUNCTION_EXPORT void loader_delete_layer_list_and_properties(const struct loader_instance *inst,
 struct loader_layer_list *layer_list) {
 uint32_t i;
 if (!layer_list) return;

 for (i = 0; i < layer_list->count; i++) {
 if (layer_list->list[i].lib_handle) {
 loader_platform_close_library(layer_list->list[i].lib_handle);
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Unloading layer library %s",
 layer_list->list[i].lib_name);
 layer_list->list[i].lib_handle = NULL;
 }
 loader_free_layer_properties(inst, &(layer_list->list[i]));
 }
 layer_list->count = 0;

 if (layer_list->capacity > 0) {
 layer_list->capacity = 0;
 loader_instance_heap_free(inst, layer_list->list);
 }
 memset(layer_list, 0, sizeof(struct loader_layer_list));
}

void loader_remove_layer_in_list(const struct loader_instance *inst, struct loader_layer_list *layer_list,
 uint32_t layer_to_remove) {
 if (layer_list == NULL || layer_to_remove >= layer_list->count) {
 return;
 }
 loader_free_layer_properties(inst, &(layer_list->list[layer_to_remove]));

 // Remove the current invalid meta-layer from the layer list. Use memmove since we are
 // overlapping the source and destination addresses.
 if (layer_to_remove + 1 <= layer_list->count) {
 memmove(&layer_list->list[layer_to_remove], &layer_list->list[layer_to_remove + 1],
 sizeof(struct loader_layer_properties) * (layer_list->count - 1 - layer_to_remove));
 }
 // Decrement the count (because we now have one less) and decrement the loop index since we need to
 // re-check this index.
 layer_list->count--;
}

// Remove all layers in the layer list that are blacklisted by the override layer.
// NOTE: This should only be called if an override layer is found and not expired.
void loader_remove_layers_in_blacklist(const struct loader_instance *inst, struct loader_layer_list *layer_list) {
 struct loader_layer_properties *override_prop = loader_find_layer_property(VK_OVERRIDE_LAYER_NAME, layer_list);
 if (NULL == override_prop) {
 return;
 }

 for (int32_t j = 0; j < (int32_t)(layer_list->count); j++) {
 struct loader_layer_properties cur_layer_prop = layer_list->list[j];
 const char *cur_layer_name = &cur_layer_prop.info.layerName[0];

 // Skip the override layer itself.
 if (!strcmp(VK_OVERRIDE_LAYER_NAME, cur_layer_name)) {
 continue;
 }

 // If found in the override layer's blacklist, remove it
 if (loader_find_layer_name_in_blacklist(cur_layer_name, override_prop)) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "loader_remove_layers_in_blacklist: Override layer is active and layer %s is in the blacklist inside of it. "
 "Removing that layer from current layer list.",
 cur_layer_name);
 loader_remove_layer_in_list(inst, layer_list, j);
 j--;

 // Re-do the query for the override layer
 override_prop = loader_find_layer_property(VK_OVERRIDE_LAYER_NAME, layer_list);
 }
 }
}

// Remove all layers in the layer list that are not found inside any implicit meta-layers.
void loader_remove_layers_not_in_implicit_meta_layers(const struct loader_instance *inst, struct loader_layer_list *layer_list) {
 int32_t i;
 int32_t j;
 int32_t layer_count = (int32_t)(layer_list->count);

 for (i = 0; i < layer_count; i++) {
 layer_list->list[i].keep = false;
 }

 for (i = 0; i < layer_count; i++) {
 struct loader_layer_properties *cur_layer_prop = &layer_list->list[i];

 if (0 == (cur_layer_prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER)) {
 cur_layer_prop->keep = true;
 continue;
 }
 for (j = 0; j < layer_count; j++) {
 struct loader_layer_properties *layer_to_check = &layer_list->list[j];

 if (i == j) {
 continue;
 }

 if (layer_to_check->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER) {
 // For all layers found in this meta layer, we want to keep them as well.
 for (uint32_t comp_layer = 0; comp_layer < layer_to_check->component_layer_names.count; comp_layer++) {
 if (!strcmp(layer_to_check->component_layer_names.list[comp_layer], cur_layer_prop->info.layerName)) {
 cur_layer_prop->keep = true;
 }
 }
 }
 }
 }

 // Remove any layers we don't want to keep (Don't use layer_count here as we need it to be
 // dynamically updated if we delete a layer property in the list).
 for (i = 0; i < (int32_t)(layer_list->count); i++) {
 struct loader_layer_properties *cur_layer_prop = &layer_list->list[i];
 if (!cur_layer_prop->keep) {
 loader_log(
 inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "loader_remove_layers_not_in_implicit_meta_layers : Implicit meta-layers are active, and layer %s is not list "
 "inside of any. So removing layer from current layer list.",
 cur_layer_prop->info.layerName);
 loader_remove_layer_in_list(inst, layer_list, i);
 i--;
 }
 }
}

VkResult loader_add_instance_extensions(const struct loader_instance *inst,
 const PFN_vkEnumerateInstanceExtensionProperties fp_get_props, const char *lib_name,
 struct loader_extension_list *ext_list) {
 uint32_t i, count = 0;
 VkExtensionProperties *ext_props;
 VkResult res = VK_SUCCESS;

 if (!fp_get_props) {
 // No EnumerateInstanceExtensionProperties defined
 goto out;
 }

 // Make sure we never call ourself by accident, this should never happen outside of error paths
 if (fp_get_props == vkEnumerateInstanceExtensionProperties) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_instance_extensions: %s's vkEnumerateInstanceExtensionProperties points to the loader, this would "
 "lead to infinite recursion.",
 lib_name);
 goto out;
 }

 res = fp_get_props(NULL, &count, NULL);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_instance_extensions: Error getting Instance extension count from %s", lib_name);
 goto out;
 }

 if (count == 0) {
 // No ExtensionProperties to report
 goto out;
 }

 ext_props = loader_stack_alloc(count * sizeof(VkExtensionProperties));
 if (NULL == ext_props) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 memset(ext_props, 0, count * sizeof(VkExtensionProperties));

 uint32_t allocated_count = count;
 res = fp_get_props(NULL, &count, ext_props);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_add_instance_extensions: Error getting Instance extensions from %s",
 lib_name);
 goto out;
 }

 // The count returned by the second call sizes the array, but never read past what we actually allocated.
 for (i = 0; i < count && i < allocated_count; i++) {
 bool ext_unsupported = wsi_unsupported_instance_extension(&ext_props[i]);
 if (!ext_unsupported) {
 res = loader_add_to_ext_list(inst, ext_list, 1, &ext_props[i]);
 if (res != VK_SUCCESS) {
 goto out;
 }
 }
 }

out:
 return res;
}

VkResult loader_add_device_extensions(const struct loader_instance *inst,
 PFN_vkEnumerateDeviceExtensionProperties fpEnumerateDeviceExtensionProperties,
 VkPhysicalDevice physical_device, const char *lib_name,
 struct loader_extension_list *ext_list) {
 uint32_t i = 0, count = 0;
 VkResult res = VK_SUCCESS;
 VkExtensionProperties *ext_props = NULL;

 res = fpEnumerateDeviceExtensionProperties(physical_device, NULL, &count, NULL);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_device_extensions: Error getting physical device extension info count from library %s", lib_name);
 return res;
 }
 if (count > 0) {
 ext_props = loader_stack_alloc(count * sizeof(VkExtensionProperties));
 if (!ext_props) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_device_extensions: Failed to allocate space for device extension properties from library %s.",
 lib_name);
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 uint32_t allocated_count = count;
 res = fpEnumerateDeviceExtensionProperties(physical_device, NULL, &count, ext_props);
 if (res != VK_SUCCESS) {
 return res;
 }
 // The count returned by the second call sizes the array, but never read past what we actually allocated.
 for (i = 0; i < count && i < allocated_count; i++) {
 res = loader_add_to_ext_list(inst, ext_list, 1, &ext_props[i]);
 if (res != VK_SUCCESS) {
 return res;
 }
 }
 }

 return VK_SUCCESS;
}

VkResult loader_init_generic_list(const struct loader_instance *inst, struct loader_generic_list *list_info, size_t element_size) {
 size_t capacity = 32 * element_size;
 list_info->count = 0;
 list_info->capacity = 0;
 list_info->list = loader_instance_heap_calloc(inst, capacity, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (list_info->list == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_init_generic_list: Failed to allocate space for generic list");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 list_info->capacity = capacity;
 return VK_SUCCESS;
}

VkResult loader_resize_generic_list(const struct loader_instance *inst, struct loader_generic_list *list_info) {
 size_t new_capacity = list_info->capacity * 2;
 void *new_ptr =
 loader_instance_heap_realloc(inst, list_info->list, list_info->capacity, new_capacity, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (new_ptr == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_resize_generic_list: Failed to allocate space for generic list");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 // Consumers of the grown region expect unused entries to read as zero (eg a VK_NULL_HANDLE surface). An app supplied
 // pfnReallocation is not required to zero the newly grown bytes, so do it here rather than relying on the allocator.
 memset((uint8_t *)new_ptr + list_info->capacity, 0, new_capacity - list_info->capacity);
 list_info->list = new_ptr;
 list_info->capacity = new_capacity;
 return VK_SUCCESS;
}

void loader_destroy_generic_list(const struct loader_instance *inst, struct loader_generic_list *list) {
 loader_instance_heap_free(inst, list->list);
 memset(list, 0, sizeof(struct loader_generic_list));
}

VkResult loader_get_next_available_entry(const struct loader_instance *inst, struct loader_used_object_list *list_info,
 uint32_t *free_index, const VkAllocationCallbacks *pAllocator) {
 if (NULL == list_info->list) {
 VkResult res =
 loader_init_generic_list(inst, (struct loader_generic_list *)list_info, sizeof(struct loader_used_object_status));
 if (VK_SUCCESS != res) {
 return res;
 }
 }
 for (uint32_t i = 0; i < list_info->capacity / sizeof(struct loader_used_object_status); i++) {
 if (list_info->list[i].status == VK_FALSE) {
 list_info->list[i].status = VK_TRUE;
 if (pAllocator) {
 list_info->list[i].allocation_callbacks = *pAllocator;
 } else {
 memset(&list_info->list[i].allocation_callbacks, 0, sizeof(VkAllocationCallbacks));
 }
 *free_index = i;
 return VK_SUCCESS;
 }
 }
 // No free space, must resize

 size_t old_capacity = list_info->capacity;
 VkResult res = loader_resize_generic_list(inst, (struct loader_generic_list *)list_info);
 if (VK_SUCCESS != res) {
 return res;
 }
 uint32_t new_index = (uint32_t)(old_capacity / sizeof(struct loader_used_object_status));
 // Zero out the newly allocated back half of list.
 memset(&list_info->list[new_index], 0, old_capacity);
 list_info->list[new_index].status = VK_TRUE;
 if (pAllocator) {
 list_info->list[new_index].allocation_callbacks = *pAllocator;
 } else {
 memset(&list_info->list[new_index].allocation_callbacks, 0, sizeof(VkAllocationCallbacks));
 }
 *free_index = new_index;
 return VK_SUCCESS;
}

void loader_release_object_from_list(struct loader_used_object_list *list_info, uint32_t index_to_free) {
 if (list_info->list && list_info->capacity > index_to_free * sizeof(struct loader_used_object_status)) {
 list_info->list[index_to_free].status = VK_FALSE;
 memset(&list_info->list[index_to_free].allocation_callbacks, 0, sizeof(VkAllocationCallbacks));
 }
}

// Append non-duplicate extension properties defined in props to the given ext_list.
// Return - Vk_SUCCESS on success
VkResult loader_add_to_ext_list(const struct loader_instance *inst, struct loader_extension_list *ext_list,
 uint32_t prop_list_count, const VkExtensionProperties *props) {
 if (ext_list->list == NULL || ext_list->capacity == 0) {
 VkResult res = loader_init_generic_list(inst, (struct loader_generic_list *)ext_list, sizeof(VkExtensionProperties));
 if (VK_SUCCESS != res) {
 return res;
 }
 }

 for (uint32_t i = 0; i < prop_list_count; i++) {
 const VkExtensionProperties *cur_ext = &props[i];

 // look for duplicates
 if (has_vk_extension_property(cur_ext, ext_list)) {
 continue;
 }

 // add to list at end
 // check for enough capacity
 if (ext_list->count * sizeof(VkExtensionProperties) >= ext_list->capacity) {
 void *new_ptr = loader_instance_heap_realloc(inst, ext_list->list, ext_list->capacity, ext_list->capacity * 2,
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (new_ptr == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_to_ext_list: Failed to reallocate space for extension list");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 ext_list->list = new_ptr;

 // double capacity
 ext_list->capacity *= 2;
 }

 memcpy(&ext_list->list[ext_list->count], cur_ext, sizeof(VkExtensionProperties));
 ext_list->count++;
 }
 return VK_SUCCESS;
}

// Append one extension property defined in props with entrypoints defined in entries to the given
// ext_list. Do not append if a duplicate.
// If this is a duplicate, this function free's the passed in entries - as in it takes ownership over that list (if it is not
// NULL) Return - Vk_SUCCESS on success
VkResult loader_add_to_dev_ext_list(const struct loader_instance *inst, struct loader_device_extension_list *ext_list,
 const VkExtensionProperties *props, struct loader_string_list *entrys) {
 VkResult res = VK_SUCCESS;
 bool should_free_entrys = true;
 if (ext_list->list == NULL || ext_list->capacity == 0) {
 res = loader_init_generic_list(inst, (struct loader_generic_list *)ext_list, sizeof(struct loader_dev_ext_props));
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 // look for duplicates
 if (has_vk_dev_ext_property(props, ext_list)) {
 goto out;
 }

 uint32_t idx = ext_list->count;
 // add to list at end
 // check for enough capacity
 if (idx * sizeof(struct loader_dev_ext_props) >= ext_list->capacity) {
 void *new_ptr = loader_instance_heap_realloc(inst, ext_list->list, ext_list->capacity, ext_list->capacity * 2,
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);

 if (NULL == new_ptr) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_to_dev_ext_list: Failed to reallocate space for device extension list");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 ext_list->list = new_ptr;

 // double capacity
 ext_list->capacity *= 2;
 }

 memcpy(&ext_list->list[idx].props, props, sizeof(*props));
 if (entrys) {
 ext_list->list[idx].entrypoints = *entrys;
 should_free_entrys = false;
 } else {
 memset(&ext_list->list[idx].entrypoints, 0, sizeof(ext_list->list[idx].entrypoints));
 }
 ext_list->count++;
out:
 if (NULL != entrys && should_free_entrys) {
 free_string_list(inst, entrys);
 }
 return res;
}

// Create storage for pointers to loader_layer_properties
bool loader_init_pointer_layer_list(const struct loader_instance *inst, struct loader_pointer_layer_list *list) {
 list->capacity = 32 * sizeof(void *);
 list->list = loader_instance_heap_calloc(inst, list->capacity, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (list->list == NULL) {
 return false;
 }
 list->count = 0;
 return true;
}

// Search the given array of layer names for an entry matching the given VkLayerProperties
bool loader_names_array_has_layer_property(const VkLayerProperties *vk_layer_prop, uint32_t layer_info_count,
 struct activated_layer_info *layer_info) {
 for (uint32_t i = 0; i < layer_info_count; i++) {
 if (strcmp(vk_layer_prop->layerName, layer_info[i].name) == 0) {
 return true;
 }
 }
 return false;
}

void loader_destroy_pointer_layer_list(const struct loader_instance *inst, struct loader_pointer_layer_list *layer_list) {
 loader_instance_heap_free(inst, layer_list->list);
 memset(layer_list, 0, sizeof(struct loader_pointer_layer_list));
}

// Append layer properties defined in prop_list to the given layer_info list
VkResult loader_add_layer_properties_to_list(const struct loader_instance *inst, struct loader_pointer_layer_list *list,
 struct loader_layer_properties *props) {
 if (list->list == NULL || list->capacity == 0) {
 if (!loader_init_pointer_layer_list(inst, list)) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 }

 // Check for enough capacity
 if (((list->count + 1) * sizeof(struct loader_layer_properties)) >= list->capacity) {
 size_t new_capacity = list->capacity * 2;
 void *new_ptr =
 loader_instance_heap_realloc(inst, list->list, list->capacity, new_capacity, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_ptr) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_layer_properties_to_list: Realloc failed for when attempting to add new layer");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 list->list = new_ptr;
 list->capacity = new_capacity;
 }
 list->list[list->count++] = props;

 return VK_SUCCESS;
}

// Determine if the provided explicit layer should be available by querying the appropriate environmental variables.
bool loader_layer_is_available(const struct loader_instance *inst, const struct loader_envvar_all_filters *filters,
 const struct loader_layer_properties *prop) {
 bool available = true;
 bool is_implicit = (0 == (prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER));
 bool disabled_by_type =
 (is_implicit) ? (filters->disable_filter.disable_all_implicit) : (filters->disable_filter.disable_all_explicit);
 if ((filters->disable_filter.disable_all || disabled_by_type ||
 check_name_matches_filter_environment_var(prop->info.layerName, &filters->disable_filter.additional_filters)) &&
 !check_name_matches_filter_environment_var(prop->info.layerName, &filters->allow_filter)) {
 available = false;
 }
 if (check_name_matches_filter_environment_var(prop->info.layerName, &filters->enable_filter)) {
 available = true;
 } else if (!available) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Layer \"%s\" forced disabled because name matches filter of env var \'%s\'.", prop->info.layerName,
 VK_LAYERS_DISABLE_ENV_VAR);
 }

 return available;
}

// Search the given search_list for any layers in the props list. Add these to the
// output layer_list.
VkResult loader_add_layer_names_to_list(const struct loader_instance *inst, const struct loader_envvar_all_filters *filters,
 struct loader_pointer_layer_list *output_list,
 struct loader_pointer_layer_list *expanded_output_list, uint32_t name_count,
 const char *const *names, const struct loader_layer_list *source_list) {
 VkResult err = VK_SUCCESS;

 for (uint32_t i = 0; i < name_count; i++) {
 const char *source_name = names[i];

 struct loader_layer_properties *layer_prop = loader_find_layer_property(source_name, source_list);
 if (NULL == layer_prop) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_names_to_list: Unable to find layer \"%s\"", source_name);
 err = VK_ERROR_LAYER_NOT_PRESENT;
 continue;
 }

 // Make sure the layer isn't already in the output_list, skip adding it if it is.
 if (loader_find_layer_name_in_list(source_name, output_list)) {
 continue;
 }

 if (!loader_layer_is_available(inst, filters, layer_prop)) {
 continue;
 }

 // If not a meta-layer, simply add it.
 if (0 == (layer_prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER)) {
 layer_prop->enabled_by_what = ENABLED_BY_WHAT_IN_APPLICATION_API;
 err = loader_add_layer_properties_to_list(inst, output_list, layer_prop);
 if (err == VK_ERROR_OUT_OF_HOST_MEMORY) return err;
 err = loader_add_layer_properties_to_list(inst, expanded_output_list, layer_prop);
 if (err == VK_ERROR_OUT_OF_HOST_MEMORY) return err;
 } else {
 err = loader_add_meta_layer(inst, filters, layer_prop, output_list, expanded_output_list, source_list, NULL);
 if (err == VK_ERROR_OUT_OF_HOST_MEMORY) return err;
 }
 }

 return err;
}

// Determine if the provided implicit layer should be enabled by querying the appropriate environmental variables.
// For an implicit layer, at least a disable environment variable is required.
bool loader_implicit_layer_is_enabled(const struct loader_instance *inst, const struct loader_envvar_all_filters *filters,
 const struct loader_layer_properties *prop) {
 bool enable = false;
 bool forced_disabled = false;
 bool forced_enabled = false;

 if ((filters->disable_filter.disable_all || filters->disable_filter.disable_all_implicit ||
 check_name_matches_filter_environment_var(prop->info.layerName, &filters->disable_filter.additional_filters)) &&
 !check_name_matches_filter_environment_var(prop->info.layerName, &filters->allow_filter)) {
 forced_disabled = true;
 }
 if (check_name_matches_filter_environment_var(prop->info.layerName, &filters->enable_filter)) {
 forced_enabled = true;
 }

 // If no enable_environment variable is specified, this implicit layer is always be enabled by default.
 if (NULL == prop->enable_env_var.name) {
 enable = true;
 } else {
 char *env_value = loader_getenv(prop->enable_env_var.name, inst);
 if (env_value && !strcmp(prop->enable_env_var.value, env_value)) {
 enable = true;
 }

 // Otherwise, only enable this layer if the enable environment variable is defined
 loader_free_getenv(env_value, inst);
 }

 if (forced_enabled) {
 // Only report a message that we've forced on a layer if it wouldn't have been enabled
 // normally.
 if (!enable) {
 enable = true;
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Implicit layer \"%s\" forced enabled due to env var \'%s\'.", prop->info.layerName,
 VK_LAYERS_ENABLE_ENV_VAR);
 }
 } else if (enable && forced_disabled) {
 enable = false;
 // Report a message that we've forced off a layer if it would have been enabled normally.
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Implicit layer \"%s\" forced disabled because name matches filter of env var \'%s\'.", prop->info.layerName,
 VK_LAYERS_DISABLE_ENV_VAR);
 return enable;
 }

 // The disable_environment has priority over everything else. If it is defined, the layer is always
 // disabled.
 if (NULL != prop->disable_env_var.name) {
 char *env_value = loader_getenv(prop->disable_env_var.name, inst);
 if (NULL != env_value) {
 enable = false;
 }
 loader_free_getenv(env_value, inst);
 } else if ((prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER) == 0) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Implicit layer \"%s\" missing disabled environment variable!", prop->info.layerName);
 }

 // Enable this layer if it is included in the override layer
 if (inst != NULL && inst->override_layer_present) {
 struct loader_layer_properties *override = NULL;
 for (uint32_t i = 0; i < inst->instance_layer_list.count; ++i) {
 if (strcmp(inst->instance_layer_list.list[i].info.layerName, VK_OVERRIDE_LAYER_NAME) == 0) {
 override = &inst->instance_layer_list.list[i];
 break;
 }
 }
 if (override != NULL) {
 for (uint32_t i = 0; i < override->component_layer_names.count; ++i) {
 if (strcmp(override->component_layer_names.list[i], prop->info.layerName) == 0) {
 enable = true;
 break;
 }
 }
 }
 }

 return enable;
}

// Check the individual implicit layer for the enable/disable environment variable settings. Only add it after
// every check has passed indicating it should be used, including making sure a layer of the same name hasn't already been
// added.
VkResult loader_add_implicit_layer(const struct loader_instance *inst, struct loader_layer_properties *prop,
 const struct loader_envvar_all_filters *filters, struct loader_pointer_layer_list *target_list,
 struct loader_pointer_layer_list *expanded_target_list,
 const struct loader_layer_list *source_list) {
 VkResult result = VK_SUCCESS;
 if (loader_implicit_layer_is_enabled(inst, filters, prop)) {
 if (0 == (prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER)) {
 // Make sure the layer isn't already in the output_list, skip adding it if it is.
 if (loader_find_layer_name_in_list(&prop->info.layerName[0], target_list)) {
 return result;
 }
 prop->enabled_by_what = ENABLED_BY_WHAT_IMPLICIT_LAYER;
 result = loader_add_layer_properties_to_list(inst, target_list, prop);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 if (NULL != expanded_target_list) {
 result = loader_add_layer_properties_to_list(inst, expanded_target_list, prop);
 }
 } else {
 result = loader_add_meta_layer(inst, filters, prop, target_list, expanded_target_list, source_list, NULL);
 }
 }
 return result;
}

// Add the component layers of a meta-layer to the active list of layers
VkResult loader_add_meta_layer(const struct loader_instance *inst, const struct loader_envvar_all_filters *filters,
 struct loader_layer_properties *prop, struct loader_pointer_layer_list *target_list,
 struct loader_pointer_layer_list *expanded_target_list, const struct loader_layer_list *source_list,
 bool *out_found_all_component_layers) {
 VkResult result = VK_SUCCESS;
 bool found_all_component_layers = true;

 // A meta-layer whose component chain loops back to itself would recurse here until the stack overflows.
 // verify_all_meta_layers rejects such cycles for layers found through normal discovery, but layers pulled
 // in from the settings file skip that check, so break the recursion on the second entry to the same layer.
 if (prop->is_being_expanded) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_meta_layer: Meta-layer %s recursively references itself through its component layers. Skipping the "
 "recursive reference.",
 prop->info.layerName);
 if (NULL != out_found_all_component_layers) {
 *out_found_all_component_layers = false;
 }
 return VK_SUCCESS;
 }
 prop->is_being_expanded = true;

 // We need to add all the individual component layers
 loader_api_version meta_layer_api_version = loader_make_version(prop->info.specVersion);
 for (uint32_t comp_layer = 0; comp_layer < prop->component_layer_names.count; comp_layer++) {
 struct loader_layer_properties *search_prop =
 loader_find_layer_property(prop->component_layer_names.list[comp_layer], source_list);
 if (search_prop != NULL) {
 loader_api_version search_prop_version = loader_make_version(prop->info.specVersion);
 if (!loader_check_version_meets_required(meta_layer_api_version, search_prop_version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Meta-layer \"%s\" API version %u.%u, component layer \"%s\" version %u.%u, may have "
 "incompatibilities (Policy #LLP_LAYER_8)!",
 prop->info.layerName, meta_layer_api_version.major, meta_layer_api_version.minor,
 search_prop->info.layerName, search_prop_version.major, search_prop_version.minor);
 }

 if (!loader_layer_is_available(inst, filters, search_prop)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Meta Layer \"%s\" component layer \"%s\" disabled.", prop->info.layerName, search_prop->info.layerName);
 continue;
 }

 // If the component layer is itself an implicit layer, we need to do the implicit layer enable
 // checks
 if (0 == (search_prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER)) {
 search_prop->enabled_by_what = ENABLED_BY_WHAT_META_LAYER;
 result = loader_add_implicit_layer(inst, search_prop, filters, target_list, expanded_target_list, source_list);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 } else {
 if (0 != (search_prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER)) {
 bool found_layers_in_component_meta_layer = true;
 search_prop->enabled_by_what = ENABLED_BY_WHAT_META_LAYER;
 result = loader_add_meta_layer(inst, filters, search_prop, target_list, expanded_target_list, source_list,
 &found_layers_in_component_meta_layer);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 if (!found_layers_in_component_meta_layer) found_all_component_layers = false;
 } else if (!loader_find_layer_name_in_list(&search_prop->info.layerName[0], target_list)) {
 // Make sure the layer isn't already in the output_list, skip adding it if it is.
 search_prop->enabled_by_what = ENABLED_BY_WHAT_META_LAYER;
 result = loader_add_layer_properties_to_list(inst, target_list, search_prop);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 if (NULL != expanded_target_list) {
 result = loader_add_layer_properties_to_list(inst, expanded_target_list, search_prop);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 }
 }
 }
 } else {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Failed to find layer name \"%s\" component layer \"%s\" to activate (Policy #LLP_LAYER_7)",
 prop->component_layer_names.list[comp_layer], prop->component_layer_names.list[comp_layer]);
 found_all_component_layers = false;
 }
 }

 prop->is_being_expanded = false;

 // Add this layer to the overall target list (not the expanded one)
 if (found_all_component_layers) {
 prop->enabled_by_what = ENABLED_BY_WHAT_META_LAYER;
 result = loader_add_layer_properties_to_list(inst, target_list, prop);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 // Write the result to out_found_all_component_layers in case this function is being recursed
 if (out_found_all_component_layers) *out_found_all_component_layers = found_all_component_layers;
 }

 return result;
}

VkExtensionProperties *get_extension_property(const char *name, const struct loader_extension_list *list) {
 for (uint32_t i = 0; i < list->count; i++) {
 if (strcmp(name, list->list[i].extensionName) == 0) return &list->list[i];
 }
 return NULL;
}

VkExtensionProperties *get_dev_extension_property(const char *name, const struct loader_device_extension_list *list) {
 for (uint32_t i = 0; i < list->count; i++) {
 if (strcmp(name, list->list[i].props.extensionName) == 0) return &list->list[i].props;
 }
 return NULL;
}

// For Instance extensions implemented within the loader (i.e. DEBUG_REPORT
// the extension must provide two entry points for the loader to use:
// - "trampoline" entry point - this is the address returned by GetProcAddr
// and will always do what's necessary to support a
// global call.
// - "terminator" function - this function will be put at the end of the
// instance chain and will contain the necessary logic
// to call / process the extension for the appropriate
// ICDs that are available.
// There is no generic mechanism for including these functions, the references
// must be placed into the appropriate loader entry points.
// GetInstanceProcAddr: call extension GetInstanceProcAddr to check for GetProcAddr
// requests
// loader_coalesce_extensions(void) - add extension records to the list of global
// extension available to the app.
// instance_disp - add function pointer for terminator function
// to this array.
// The extension itself should be in a separate file that will be linked directly
// with the loader.
VkResult loader_get_icd_loader_instance_extensions(const struct loader_instance *inst, struct loader_icd_tramp_list *icd_tramp_list,
 struct loader_extension_list *inst_exts) {
 struct loader_extension_list icd_exts;
 VkResult res = VK_SUCCESS;
 char *env_value;
 bool filter_extensions = true;

 // Check if a user wants to disable the instance extension filtering behavior
 env_value = loader_getenv("VK_LOADER_DISABLE_INST_EXT_FILTER", inst);
 if (NULL != env_value && atoi(env_value) != 0) {
 filter_extensions = false;
 }
 loader_free_getenv(env_value, inst);

 // traverse scanned icd list adding non-duplicate extensions to the list
 for (uint32_t i = 0; i < icd_tramp_list->count; i++) {
 res = loader_init_generic_list(inst, (struct loader_generic_list *)&icd_exts, sizeof(VkExtensionProperties));
 if (VK_SUCCESS != res) {
 goto out;
 }
 res = loader_add_instance_extensions(inst, icd_tramp_list->scanned_list[i].EnumerateInstanceExtensionProperties,
 icd_tramp_list->scanned_list[i].lib_name, &icd_exts);
 if (VK_SUCCESS == res) {
 if (filter_extensions) {
 // Remove any extensions not recognized by the loader
 for (int32_t j = 0; j < (int32_t)icd_exts.count; j++) {
 // See if the extension is in the list of supported extensions
 bool found = false;
 for (uint32_t k = 0; LOADER_INSTANCE_EXTENSIONS[k] != NULL; k++) {
 if (strcmp(icd_exts.list[j].extensionName, LOADER_INSTANCE_EXTENSIONS[k]) == 0) {
 found = true;
 break;
 }
 }

 // If it isn't in the list, remove it
 if (!found) {
 for (uint32_t k = j + 1; k < icd_exts.count; k++) {
 icd_exts.list[k - 1] = icd_exts.list[k];
 }
 --icd_exts.count;
 --j;
 }
 }
 }

 res = loader_add_to_ext_list(inst, inst_exts, icd_exts.count, icd_exts.list);
 }
 loader_destroy_generic_list(inst, (struct loader_generic_list *)&icd_exts);
 if (VK_SUCCESS != res) {
 goto out;
 }
 };

 // Traverse loader's extensions, adding non-duplicate extensions to the list
 res = add_debug_extensions_to_ext_list(inst, inst_exts);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 const VkExtensionProperties portability_enumeration_extension_info[] = {
 {VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME, VK_KHR_PORTABILITY_ENUMERATION_SPEC_VERSION}};

 // Add VK_KHR_portability_subset
 res = loader_add_to_ext_list(inst, inst_exts, sizeof(portability_enumeration_extension_info) / sizeof(VkExtensionProperties),
 portability_enumeration_extension_info);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }

 const VkExtensionProperties direct_driver_loading_extension_info[] = {
 {VK_LUNARG_DIRECT_DRIVER_LOADING_EXTENSION_NAME, VK_LUNARG_DIRECT_DRIVER_LOADING_SPEC_VERSION}};

 // Add VK_LUNARG_direct_driver_loading
 res = loader_add_to_ext_list(inst, inst_exts, sizeof(direct_driver_loading_extension_info) / sizeof(VkExtensionProperties),
 direct_driver_loading_extension_info);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }

out:
 return res;
}

struct loader_icd_term *loader_get_icd_and_device(const void *device, struct loader_device **found_dev) {
 VkLayerDispatchTable *dispatch_table_device = loader_get_dispatch(device);
 if (NULL == dispatch_table_device) {
 *found_dev = NULL;
 return NULL;
 }
 loader_platform_thread_lock_mutex(&loader_lock);
 *found_dev = NULL;

 for (struct loader_instance *inst = loader.instances; inst; inst = inst->next) {
 for (struct loader_icd_term *icd_term = inst->icd_terms; icd_term; icd_term = icd_term->next) {
 for (struct loader_device *dev = icd_term->logical_device_list; dev; dev = dev->next) {
 // Value comparison of device prevents object wrapping by layers
 if (loader_get_dispatch(dev->icd_device) == dispatch_table_device ||
 (dev->chain_device != VK_NULL_HANDLE && loader_get_dispatch(dev->chain_device) == dispatch_table_device)) {
 *found_dev = dev;
 loader_platform_thread_unlock_mutex(&loader_lock);
 return icd_term;
 }
 }
 }
 }
 loader_platform_thread_unlock_mutex(&loader_lock);
 return NULL;
}

void loader_destroy_logical_device(struct loader_device *dev, const VkAllocationCallbacks *pAllocator) {
 if (pAllocator) {
 dev->alloc_callbacks = *pAllocator;
 }
 loader_device_heap_free(dev, dev);
}

struct loader_device *loader_create_logical_device(const struct loader_instance *inst, const VkAllocationCallbacks *pAllocator) {
 struct loader_device *new_dev;
 new_dev = loader_calloc(pAllocator, sizeof(struct loader_device), VK_SYSTEM_ALLOCATION_SCOPE_DEVICE);

 if (!new_dev) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_create_logical_device: Failed to alloc struct loader_device");
 return NULL;
 }

 new_dev->loader_dispatch.core_dispatch.magic = DEVICE_DISP_TABLE_MAGIC_NUMBER;

 if (pAllocator) {
 new_dev->alloc_callbacks = *pAllocator;
 }

 return new_dev;
}

void loader_add_logical_device(struct loader_icd_term *icd_term, struct loader_device *dev) {
 dev->next = icd_term->logical_device_list;
 icd_term->logical_device_list = dev;
}

void loader_remove_logical_device(struct loader_icd_term *icd_term, struct loader_device *found_dev,
 const VkAllocationCallbacks *pAllocator) {
 struct loader_device *dev, *prev_dev;

 if (!icd_term || !found_dev) return;

 prev_dev = NULL;
 dev = icd_term->logical_device_list;
 while (dev && dev != found_dev) {
 prev_dev = dev;
 dev = dev->next;
 }

 if (prev_dev)
 prev_dev->next = found_dev->next;
 else
 icd_term->logical_device_list = found_dev->next;
 loader_destroy_logical_device(found_dev, pAllocator);
}

const VkAllocationCallbacks *ignore_null_callback(const VkAllocationCallbacks *callbacks) {
 return NULL != callbacks->pfnAllocation && NULL != callbacks->pfnFree && NULL != callbacks->pfnReallocation &&
 NULL != callbacks->pfnInternalAllocation && NULL != callbacks->pfnInternalFree
 ? callbacks
 : NULL;
}

// Try to close any open objects on the loader_icd_term - this must be done before destroying the instance
void loader_icd_close_objects(struct loader_instance *ptr_inst, struct loader_icd_term *icd_term) {
 for (uint32_t i = 0; i < icd_term->surface_list.capacity / sizeof(VkSurfaceKHR); i++) {
 if (ptr_inst->surfaces_list.capacity > i * sizeof(struct loader_used_object_status) &&
 ptr_inst->surfaces_list.list[i].status == VK_TRUE && NULL != icd_term->surface_list.list &&
 icd_term->surface_list.list[i] && NULL != icd_term->dispatch.DestroySurfaceKHR) {
 icd_term->dispatch.DestroySurfaceKHR(icd_term->instance, icd_term->surface_list.list[i],
 ignore_null_callback(&(ptr_inst->surfaces_list.list[i].allocation_callbacks)));
 icd_term->surface_list.list[i] = (VkSurfaceKHR)(uintptr_t)NULL;
 }
 }
 for (uint32_t i = 0; i < icd_term->debug_utils_messenger_list.capacity / sizeof(VkDebugUtilsMessengerEXT); i++) {
 if (ptr_inst->debug_utils_messengers_list.capacity > i * sizeof(struct loader_used_object_status) &&
 ptr_inst->debug_utils_messengers_list.list[i].status == VK_TRUE && NULL != icd_term->debug_utils_messenger_list.list &&
 icd_term->debug_utils_messenger_list.list[i] && NULL != icd_term->dispatch.DestroyDebugUtilsMessengerEXT) {
 icd_term->dispatch.DestroyDebugUtilsMessengerEXT(
 icd_term->instance, icd_term->debug_utils_messenger_list.list[i],
 ignore_null_callback(&(ptr_inst->debug_utils_messengers_list.list[i].allocation_callbacks)));
 icd_term->debug_utils_messenger_list.list[i] = (VkDebugUtilsMessengerEXT)(uintptr_t)NULL;
 }
 }
 for (uint32_t i = 0; i < icd_term->debug_report_callback_list.capacity / sizeof(VkDebugReportCallbackEXT); i++) {
 if (ptr_inst->debug_report_callbacks_list.capacity > i * sizeof(struct loader_used_object_status) &&
 ptr_inst->debug_report_callbacks_list.list[i].status == VK_TRUE && NULL != icd_term->debug_report_callback_list.list &&
 icd_term->debug_report_callback_list.list[i] && NULL != icd_term->dispatch.DestroyDebugReportCallbackEXT) {
 icd_term->dispatch.DestroyDebugReportCallbackEXT(
 icd_term->instance, icd_term->debug_report_callback_list.list[i],
 ignore_null_callback(&(ptr_inst->debug_report_callbacks_list.list[i].allocation_callbacks)));
 icd_term->debug_report_callback_list.list[i] = (VkDebugReportCallbackEXT)(uintptr_t)NULL;
 }
 }
}
// Free resources allocated inside the loader_icd_term
void loader_icd_destroy(struct loader_instance *ptr_inst, struct loader_icd_term *icd_term,
 const VkAllocationCallbacks *pAllocator) {
 ptr_inst->icd_terms_count--;
 for (struct loader_device *dev = icd_term->logical_device_list; dev;) {
 struct loader_device *next_dev = dev->next;
 loader_destroy_logical_device(dev, pAllocator);
 dev = next_dev;
 }

 loader_destroy_generic_list(ptr_inst, (struct loader_generic_list *)&icd_term->surface_list);
 loader_destroy_generic_list(ptr_inst, (struct loader_generic_list *)&icd_term->debug_utils_messenger_list);
 loader_destroy_generic_list(ptr_inst, (struct loader_generic_list *)&icd_term->debug_report_callback_list);

 loader_instance_heap_free(ptr_inst, icd_term);
}

struct loader_icd_term *loader_icd_add(struct loader_instance *ptr_inst, const struct loader_scanned_icd *scanned_icd) {
 struct loader_icd_term *icd_term;

 icd_term = loader_instance_heap_calloc(ptr_inst, sizeof(struct loader_icd_term), VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (!icd_term) {
 return NULL;
 }

 icd_term->scanned_icd = scanned_icd;
 icd_term->this_instance = ptr_inst;

 // Prepend to the list
 icd_term->next = ptr_inst->icd_terms;
 ptr_inst->icd_terms = icd_term;
 ptr_inst->icd_terms_count++;

 return icd_term;
}
// Closes the library handle in the scanned ICD, free the lib_name string, and zeros out all data
void loader_unload_scanned_icd(struct loader_instance *inst, struct loader_scanned_icd *scanned_icd) {
 if (NULL == scanned_icd) {
 return;
 }
 if (scanned_icd->handle) {
 loader_platform_close_library(scanned_icd->handle);
 scanned_icd->handle = NULL;
 }
 loader_instance_heap_free(inst, scanned_icd->lib_name);
 memset(scanned_icd, 0, sizeof(struct loader_scanned_icd));
}

// Determine the ICD interface version to use.
// @param icd
// @param pVersion Output parameter indicating which version to use or 0 if
// the negotiation API is not supported by the ICD
// @return bool indicating true if the selected interface version is supported
// by the loader, false indicates the version is not supported
bool loader_get_icd_interface_version(PFN_vkNegotiateLoaderICDInterfaceVersion fp_negotiate_icd_version, uint32_t *pVersion) {
 if (fp_negotiate_icd_version == NULL) {
 // ICD does not support the negotiation API, it supports version 0 or 1
 // calling code must determine if it is version 0 or 1
 *pVersion = 0;
 } else {
 // ICD supports the negotiation API, so call it with the loader's
 // latest version supported
 *pVersion = CURRENT_LOADER_ICD_INTERFACE_VERSION;
 VkResult result = fp_negotiate_icd_version(pVersion);

 if (result == VK_ERROR_INCOMPATIBLE_DRIVER) {
 // ICD no longer supports the loader's latest interface version so
 // fail loading the ICD
 return false;
 }
 }

#if MIN_SUPPORTED_LOADER_ICD_INTERFACE_VERSION > 0
 if (*pVersion < MIN_SUPPORTED_LOADER_ICD_INTERFACE_VERSION) {
 // Loader no longer supports the ICD's latest interface version so fail
 // loading the ICD
 return false;
 }
#endif
 return true;
}

void loader_clear_scanned_icd_list(const struct loader_instance *inst, struct loader_icd_tramp_list *icd_tramp_list) {
 if (0 != icd_tramp_list->capacity && icd_tramp_list->scanned_list) {
 for (uint32_t i = 0; i < icd_tramp_list->count; i++) {
 if (icd_tramp_list->scanned_list[i].handle) {
 loader_platform_close_library(icd_tramp_list->scanned_list[i].handle);
 icd_tramp_list->scanned_list[i].handle = NULL;
 }
 loader_instance_heap_free(inst, icd_tramp_list->scanned_list[i].lib_name);
 }
 loader_instance_heap_free(inst, icd_tramp_list->scanned_list);
 }
 memset(icd_tramp_list, 0, sizeof(struct loader_icd_tramp_list));
}

VkResult loader_init_scanned_icd_list(const struct loader_instance *inst, struct loader_icd_tramp_list *icd_tramp_list) {
 VkResult res = VK_SUCCESS;
 loader_clear_scanned_icd_list(inst, icd_tramp_list);
 icd_tramp_list->capacity = 8 * sizeof(struct loader_scanned_icd);
 icd_tramp_list->scanned_list = loader_instance_heap_alloc(inst, icd_tramp_list->capacity, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == icd_tramp_list->scanned_list) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_init_scanned_icd_list: Realloc failed for layer list when attempting to add new layer");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 return res;
}

VkResult loader_add_direct_driver(const struct loader_instance *inst, uint32_t index,
 const VkDirectDriverLoadingInfoLUNARG *pDriver, struct loader_icd_tramp_list *icd_tramp_list) {
 // Assume pDriver is valid, since there is no real way to check it. Calling code should make sure the pointer to the array
 // of VkDirectDriverLoadingInfoLUNARG structures is non-null.
 if (NULL == pDriver->pfnGetInstanceProcAddr) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: VkDirectDriverLoadingInfoLUNARG structure at index %d contains a NULL pointer for the "
 "pfnGetInstanceProcAddr member, skipping.",
 index);
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 PFN_vkGetInstanceProcAddr fp_get_proc_addr = pDriver->pfnGetInstanceProcAddr;
 PFN_vkCreateInstance fp_create_inst = NULL;
 PFN_vkEnumerateInstanceExtensionProperties fp_get_inst_ext_props = NULL;
 PFN_GetPhysicalDeviceProcAddr fp_get_phys_dev_proc_addr = NULL;
 PFN_vkNegotiateLoaderICDInterfaceVersion fp_negotiate_icd_version = NULL;
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 PFN_vk_icdEnumerateAdapterPhysicalDevices fp_enum_dxgi_adapter_phys_devs = NULL;
#endif
 struct loader_scanned_icd *new_scanned_icd;
 uint32_t interface_version = 0;

 // Try to get the negotiate ICD interface version function
 fp_negotiate_icd_version = (PFN_vk_icdNegotiateLoaderICDInterfaceVersion)pDriver->pfnGetInstanceProcAddr(
 NULL, "vk_icdNegotiateLoaderICDInterfaceVersion");

 if (NULL == fp_negotiate_icd_version) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: Could not get 'vk_icdNegotiateLoaderICDInterfaceVersion' from "
 "VkDirectDriverLoadingInfoLUNARG structure at "
 "index %d, skipping.",
 index);
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 if (!loader_get_icd_interface_version(fp_negotiate_icd_version, &interface_version)) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: VkDirectDriverLoadingInfoLUNARG structure at index %d supports interface version %d, "
 "which is incompatible with the Loader Driver Interface version that supports the VK_LUNARG_direct_driver_loading "
 "extension, skipping.",
 index, interface_version);
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 if (interface_version < 7) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: VkDirectDriverLoadingInfoLUNARG structure at index %d supports interface version %d, "
 "which is incompatible with the Loader Driver Interface version that supports the VK_LUNARG_direct_driver_loading "
 "extension, skipping.",
 index, interface_version);
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 fp_create_inst = (PFN_vkCreateInstance)pDriver->pfnGetInstanceProcAddr(NULL, "vkCreateInstance");
 if (NULL == fp_create_inst) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: Could not get 'vkCreateInstance' from VkDirectDriverLoadingInfoLUNARG structure at "
 "index %d, skipping.",
 index);
 return VK_ERROR_INITIALIZATION_FAILED;
 }
 fp_get_inst_ext_props =
 (PFN_vkEnumerateInstanceExtensionProperties)pDriver->pfnGetInstanceProcAddr(NULL, "vkEnumerateInstanceExtensionProperties");
 if (NULL == fp_get_inst_ext_props) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: Could not get 'vkEnumerateInstanceExtensionProperties' from "
 "VkDirectDriverLoadingInfoLUNARG structure at index %d, skipping.",
 index);
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 fp_get_phys_dev_proc_addr =
 (PFN_vk_icdGetPhysicalDeviceProcAddr)pDriver->pfnGetInstanceProcAddr(NULL, "vk_icdGetPhysicalDeviceProcAddr");
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 // Query "vk_icdEnumerateAdapterPhysicalDevices" with vk_icdGetInstanceProcAddr if the library reports interface version
 // 7 or greater, otherwise fallback to loading it from the platform dynamic linker
 fp_enum_dxgi_adapter_phys_devs =
 (PFN_vk_icdEnumerateAdapterPhysicalDevices)pDriver->pfnGetInstanceProcAddr(NULL, "vk_icdEnumerateAdapterPhysicalDevices");
#endif

 // check for enough capacity
 if ((icd_tramp_list->count * sizeof(struct loader_scanned_icd)) >= icd_tramp_list->capacity) {
 void *new_ptr = loader_instance_heap_realloc(inst, icd_tramp_list->scanned_list, icd_tramp_list->capacity,
 icd_tramp_list->capacity * 2, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_ptr) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_add_direct_driver: Realloc failed on icd library list for ICD index %u", index);
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 icd_tramp_list->scanned_list = new_ptr;

 // double capacity
 icd_tramp_list->capacity *= 2;
 }

 // Driver must be 1.1 to support version 7
 uint32_t api_version = VK_API_VERSION_1_1;
 PFN_vkEnumerateInstanceVersion icd_enumerate_instance_version =
 (PFN_vkEnumerateInstanceVersion)pDriver->pfnGetInstanceProcAddr(NULL, "vkEnumerateInstanceVersion");

 if (icd_enumerate_instance_version) {
 VkResult res = icd_enumerate_instance_version(&api_version);
 if (res != VK_SUCCESS) {
 return res;
 }
 }

 new_scanned_icd = &(icd_tramp_list->scanned_list[icd_tramp_list->count]);
 new_scanned_icd->handle = NULL;
 new_scanned_icd->api_version = api_version;
 new_scanned_icd->GetInstanceProcAddr = fp_get_proc_addr;
 new_scanned_icd->GetPhysicalDeviceProcAddr = fp_get_phys_dev_proc_addr;
 new_scanned_icd->EnumerateInstanceExtensionProperties = fp_get_inst_ext_props;
 new_scanned_icd->CreateInstance = fp_create_inst;
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 new_scanned_icd->EnumerateAdapterPhysicalDevices = fp_enum_dxgi_adapter_phys_devs;
#endif
 new_scanned_icd->interface_version = interface_version;

 new_scanned_icd->lib_name = NULL;
 icd_tramp_list->count++;

 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_add_direct_driver: Adding driver found in index %d of "
 "VkDirectDriverLoadingListLUNARG::pDrivers structure. pfnGetInstanceProcAddr was set to %p",
 index, pDriver->pfnGetInstanceProcAddr);

 return VK_SUCCESS;
}

// Search through VkInstanceCreateInfo's pNext chain for any drivers from the direct driver loading extension and load them.
VkResult loader_scan_for_direct_drivers(const struct loader_instance *inst, const VkInstanceCreateInfo *pCreateInfo,
 struct loader_icd_tramp_list *icd_tramp_list, bool *direct_driver_loading_exclusive_mode) {
 if (NULL == pCreateInfo) {
 // Don't do this logic unless we are being called from vkCreateInstance, when pCreateInfo will be non-null
 return VK_SUCCESS;
 }
 bool direct_driver_loading_enabled = false;
 // Try to if VK_LUNARG_direct_driver_loading is enabled and if we are using it exclusively
 // Skip this step if inst is NULL, aka when this function is being called before instance creation
 if (inst != NULL && pCreateInfo->ppEnabledExtensionNames && pCreateInfo->enabledExtensionCount > 0) {
 // Look through the enabled extension list, make sure VK_LUNARG_direct_driver_loading is present
 for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; i++) {
 if (strcmp(pCreateInfo->ppEnabledExtensionNames[i], VK_LUNARG_DIRECT_DRIVER_LOADING_EXTENSION_NAME) == 0) {
 direct_driver_loading_enabled = true;
 break;
 }
 }
 }
 const VkDirectDriverLoadingListLUNARG *ddl_list = NULL;
 // Find the VkDirectDriverLoadingListLUNARG struct in the pNext chain of vkInstanceCreateInfo
 const void *pNext = pCreateInfo->pNext;
 while (pNext) {
 VkBaseInStructure out_structure = {0};
 memcpy(&out_structure, pNext, sizeof(VkBaseInStructure));
 if (out_structure.sType == VK_STRUCTURE_TYPE_DIRECT_DRIVER_LOADING_LIST_LUNARG) {
 ddl_list = (VkDirectDriverLoadingListLUNARG *)pNext;
 break;
 }
 pNext = out_structure.pNext;
 }
 if (NULL == ddl_list) {
 if (direct_driver_loading_enabled) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_scan_for_direct_drivers: The VK_LUNARG_direct_driver_loading extension was enabled but the "
 "pNext chain of "
 "VkInstanceCreateInfo did not contain the "
 "VkDirectDriverLoadingListLUNARG structure.");
 }
 // Always want to exit early if there was no VkDirectDriverLoadingListLUNARG in the pNext chain
 return VK_SUCCESS;
 }

 if (!direct_driver_loading_enabled) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_scan_for_direct_drivers: The pNext chain of VkInstanceCreateInfo contained the "
 "VkDirectDriverLoadingListLUNARG structure, but the VK_LUNARG_direct_driver_loading extension was "
 "not enabled.");
 return VK_SUCCESS;
 }
 // If we are using exclusive mode, skip looking for any more drivers from system or environment variables
 if (ddl_list->mode == VK_DIRECT_DRIVER_LOADING_MODE_EXCLUSIVE_LUNARG) {
 *direct_driver_loading_exclusive_mode = true;
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_scan_for_direct_drivers: The VK_LUNARG_direct_driver_loading extension is active and specified "
 "VK_DIRECT_DRIVER_LOADING_MODE_EXCLUSIVE_LUNARG, skipping system and environment "
 "variable driver search mechanisms.");
 }
 if (NULL == ddl_list->pDrivers) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_scan_for_direct_drivers: The VkDirectDriverLoadingListLUNARG structure in the pNext chain of "
 "VkInstanceCreateInfo has a NULL pDrivers member.");
 return VK_SUCCESS;
 }
 if (ddl_list->driverCount == 0) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_scan_for_direct_drivers: The VkDirectDriverLoadingListLUNARG structure in the pNext chain of "
 "VkInstanceCreateInfo has a non-null pDrivers member but a driverCount member with a value "
 "of zero.");
 return VK_SUCCESS;
 }
 // Go through all VkDirectDriverLoadingInfoLUNARG entries and add each driver
 // Because icd_tramp's are prepended, this will result in the drivers appearing at the end
 for (uint32_t i = 0; i < ddl_list->driverCount; i++) {
 VkResult res = loader_add_direct_driver(inst, i, &ddl_list->pDrivers[i], icd_tramp_list);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }
 }

 return VK_SUCCESS;
}

VkResult loader_scanned_icd_add(const struct loader_instance *inst, struct loader_icd_tramp_list *icd_tramp_list,
 const char *filename, uint32_t api_version, enum loader_layer_library_status *lib_status) {
 loader_platform_dl_handle handle = NULL;
 PFN_vkCreateInstance fp_create_inst = NULL;
 PFN_vkEnumerateInstanceExtensionProperties fp_get_inst_ext_props = NULL;
 PFN_vkGetInstanceProcAddr fp_get_proc_addr = NULL;
 PFN_GetPhysicalDeviceProcAddr fp_get_phys_dev_proc_addr = NULL;
 PFN_vkNegotiateLoaderICDInterfaceVersion fp_negotiate_icd_version = NULL;
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 PFN_vk_icdEnumerateAdapterPhysicalDevices fp_enum_dxgi_adapter_phys_devs = NULL;
#endif
 struct loader_scanned_icd *new_scanned_icd = NULL;
 uint32_t interface_vers;
 VkResult res = VK_SUCCESS;

 // This shouldn't happen, but the check is necessary because dlopen returns a handle to the main program when
 // filename is NULL
 if (filename == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_scanned_icd_add: A NULL filename was used, skipping this ICD");
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

// TODO implement smarter opening/closing of libraries. For now this
// function leaves libraries open and the scanned_icd_clear closes them
#if defined(__Fuchsia__)
 handle = loader_platform_open_driver(filename);
#else
 handle = loader_platform_open_library(filename);
#endif
 if (NULL == handle) {
 loader_handle_load_library_error(inst, filename, lib_status);
 if (lib_status && *lib_status == LOADER_LAYER_LIB_ERROR_OUT_OF_MEMORY) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 } else {
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 }
 goto out;
 }

 // Try to load the driver's exported vk_icdNegotiateLoaderICDInterfaceVersion
 fp_negotiate_icd_version = loader_platform_get_proc_address(handle, "vk_icdNegotiateLoaderICDInterfaceVersion");

 // If it isn't exported, we are dealing with either a v0, v1, or a v7 and up driver
 if (NULL == fp_negotiate_icd_version) {
 // Try to load the driver's exported vk_icdGetInstanceProcAddr - if this is a v7 or up driver, we can use it to get
 // the driver's vk_icdNegotiateLoaderICDInterfaceVersion function
 fp_get_proc_addr = loader_platform_get_proc_address(handle, "vk_icdGetInstanceProcAddr");

 // If we successfully loaded vk_icdGetInstanceProcAddr, try to get vk_icdNegotiateLoaderICDInterfaceVersion
 if (fp_get_proc_addr) {
 fp_negotiate_icd_version =
 (PFN_vk_icdNegotiateLoaderICDInterfaceVersion)fp_get_proc_addr(NULL, "vk_icdNegotiateLoaderICDInterfaceVersion");
 }
 }

 // Try to negotiate the Loader and Driver Interface Versions
 // loader_get_icd_interface_version will check if fp_negotiate_icd_version is NULL, so we don't have to.
 // If it *is* NULL, that means this driver uses interface version 0 or 1
 if (!loader_get_icd_interface_version(fp_negotiate_icd_version, &interface_vers)) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: ICD %s doesn't support interface version compatible with loader, skip this ICD.",
 filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 // If we didn't already query vk_icdGetInstanceProcAddr, try now
 if (NULL == fp_get_proc_addr) {
 fp_get_proc_addr = loader_platform_get_proc_address(handle, "vk_icdGetInstanceProcAddr");
 }

 // If vk_icdGetInstanceProcAddr is NULL, this ICD is using version 0 and so we should respond accordingly.
 if (NULL == fp_get_proc_addr) {
 // Exporting vk_icdNegotiateLoaderICDInterfaceVersion but not vk_icdGetInstanceProcAddr violates Version 2's
 // requirements, as for Version 2 to be supported Version 1 must also be supported
 if (interface_vers != 0) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: ICD %s reports an interface version of %d but doesn't export "
 "vk_icdGetInstanceProcAddr, skip this ICD.",
 filename, interface_vers);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 // Use deprecated interface from version 0
 fp_get_proc_addr = loader_platform_get_proc_address(handle, "vkGetInstanceProcAddr");
 if (NULL == fp_get_proc_addr) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: Attempt to retrieve either \'vkGetInstanceProcAddr\' or "
 "\'vk_icdGetInstanceProcAddr\' from ICD %s failed.",
 filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 } else {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_scanned_icd_add: Using deprecated ICD interface of \'vkGetInstanceProcAddr\' instead of "
 "\'vk_icdGetInstanceProcAddr\' for ICD %s",
 filename);
 }
 fp_create_inst = loader_platform_get_proc_address(handle, "vkCreateInstance");
 if (NULL == fp_create_inst) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: Failed querying \'vkCreateInstance\' via dlsym/LoadLibrary for ICD %s", filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 fp_get_inst_ext_props = loader_platform_get_proc_address(handle, "vkEnumerateInstanceExtensionProperties");
 if (NULL == fp_get_inst_ext_props) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: Could not get \'vkEnumerateInstanceExtensionProperties\' via dlsym/LoadLibrary "
 "for ICD %s",
 filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 } else {
 // vk_icdGetInstanceProcAddr was successfully found, we can assume the version is at least one
 // If vk_icdNegotiateLoaderICDInterfaceVersion was also found, interface_vers must be 2 or greater, so this check is
 // fine
 if (interface_vers == 0) {
 interface_vers = 1;
 }

 fp_create_inst = (PFN_vkCreateInstance)fp_get_proc_addr(NULL, "vkCreateInstance");
 if (NULL == fp_create_inst) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: Could not get \'vkCreateInstance\' via \'vk_icdGetInstanceProcAddr\' for ICD %s",
 filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 fp_get_inst_ext_props =
 (PFN_vkEnumerateInstanceExtensionProperties)fp_get_proc_addr(NULL, "vkEnumerateInstanceExtensionProperties");
 if (NULL == fp_get_inst_ext_props) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_scanned_icd_add: Could not get \'vkEnumerateInstanceExtensionProperties\' via "
 "\'vk_icdGetInstanceProcAddr\' for ICD %s",
 filename);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 // Query "vk_icdGetPhysicalDeviceProcAddr" with vk_icdGetInstanceProcAddr if the library reports interface version 7 or
 // greater, otherwise fallback to loading it from the platform dynamic linker
 if (interface_vers >= 7) {
 fp_get_phys_dev_proc_addr =
 (PFN_vk_icdGetPhysicalDeviceProcAddr)fp_get_proc_addr(NULL, "vk_icdGetPhysicalDeviceProcAddr");
 }
 if (NULL == fp_get_phys_dev_proc_addr && interface_vers >= 3) {
 fp_get_phys_dev_proc_addr = loader_platform_get_proc_address(handle, "vk_icdGetPhysicalDeviceProcAddr");
 }
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 // Query "vk_icdEnumerateAdapterPhysicalDevices" with vk_icdGetInstanceProcAddr if the library reports interface version
 // 7 or greater, otherwise fallback to loading it from the platform dynamic linker
 if (interface_vers >= 7) {
 fp_enum_dxgi_adapter_phys_devs =
 (PFN_vk_icdEnumerateAdapterPhysicalDevices)fp_get_proc_addr(NULL, "vk_icdEnumerateAdapterPhysicalDevices");
 }
 if (NULL == fp_enum_dxgi_adapter_phys_devs && interface_vers >= 6) {
 fp_enum_dxgi_adapter_phys_devs = loader_platform_get_proc_address(handle, "vk_icdEnumerateAdapterPhysicalDevices");
 }
#endif
 }

 // check for enough capacity
 if ((icd_tramp_list->count * sizeof(struct loader_scanned_icd)) >= icd_tramp_list->capacity) {
 void *new_ptr = loader_instance_heap_realloc(inst, icd_tramp_list->scanned_list, icd_tramp_list->capacity,
 icd_tramp_list->capacity * 2, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_ptr) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_scanned_icd_add: Realloc failed on icd library list for ICD %s",
 filename);
 goto out;
 }
 icd_tramp_list->scanned_list = new_ptr;

 // double capacity
 icd_tramp_list->capacity *= 2;
 }

 loader_api_version api_version_struct = loader_make_version(api_version);
 if (interface_vers <= 4 && loader_check_version_meets_required(LOADER_VERSION_1_1_0, api_version_struct)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_scanned_icd_add: Driver %s supports Vulkan %u.%u, but only supports loader interface version %u."
 " Interface version 5 or newer required to support this version of Vulkan (Policy #LDP_DRIVER_7)",
 filename, api_version_struct.major, api_version_struct.minor, interface_vers);
 }

 new_scanned_icd = &(icd_tramp_list->scanned_list[icd_tramp_list->count]);
 new_scanned_icd->handle = handle;
 new_scanned_icd->api_version = api_version;
 new_scanned_icd->GetInstanceProcAddr = fp_get_proc_addr;
 new_scanned_icd->GetPhysicalDeviceProcAddr = fp_get_phys_dev_proc_addr;
 new_scanned_icd->EnumerateInstanceExtensionProperties = fp_get_inst_ext_props;
 new_scanned_icd->CreateInstance = fp_create_inst;
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 new_scanned_icd->EnumerateAdapterPhysicalDevices = fp_enum_dxgi_adapter_phys_devs;
#endif
 new_scanned_icd->interface_version = interface_vers;

 res = loader_copy_to_new_str(inst, filename, &new_scanned_icd->lib_name);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_scanned_icd_add: Out of memory can't add ICD %s", filename);
 goto out;
 }

 // Uses OS calls to find the 'true' path to the binary, for more accurate logging later on.
 res = fixup_library_binary_path(inst, &(new_scanned_icd->lib_name), new_scanned_icd->handle, fp_get_proc_addr);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 loader_instance_heap_free(inst, new_scanned_icd->lib_name);
 goto out;
 }

 icd_tramp_list->count++;

out:
 if (res != VK_SUCCESS) {
 if (NULL != handle) {
 loader_platform_close_library(handle);
 }
 }

 return res;
}

#if defined(_WIN32)
BOOL __stdcall loader_initialize(PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context) {
 (void)InitOnce;
 (void)Parameter;
 (void)Context;
#else
void loader_initialize(void) {
 loader_platform_thread_create_mutex(&loader_lock);
 loader_platform_thread_create_mutex(&loader_preload_icd_lock);
 init_global_loader_settings();
#endif

 // initialize logging
 loader_init_global_debug_level();
#if defined(_WIN32)
 windows_initialization();
#endif

 loader_api_version version = loader_make_full_version(VK_HEADER_VERSION_COMPLETE);
 loader_log(NULL, VULKAN_LOADER_INFO_BIT, 0, "Vulkan Loader Version %d.%d.%d", version.major, version.minor, version.patch);

#if defined(GIT_BRANCH_NAME) && defined(GIT_TAG_INFO)
 loader_log(NULL, VULKAN_LOADER_INFO_BIT, 0, "[Vulkan Loader Git - Tag: " GIT_BRANCH_NAME ", Branch/Commit: " GIT_TAG_INFO "]");
#endif

 char *loader_disable_dynamic_library_unloading_env_var = loader_getenv("VK_LOADER_DISABLE_DYNAMIC_LIBRARY_UNLOADING", NULL);
 if (loader_disable_dynamic_library_unloading_env_var &&
 0 == strncmp(loader_disable_dynamic_library_unloading_env_var, "1", 2)) {
 loader_disable_dynamic_library_unloading = true;
 loader_log(NULL, VULKAN_LOADER_WARN_BIT, 0, "Vulkan Loader: library unloading is disabled");
 } else {
 loader_disable_dynamic_library_unloading = false;
 }
 loader_free_getenv(loader_disable_dynamic_library_unloading_env_var, NULL);
#if defined(LOADER_USE_UNSAFE_FILE_SEARCH)
 loader_log(NULL, VULKAN_LOADER_WARN_BIT, 0, "Vulkan Loader: unsafe searching is enabled");
#endif
#if defined(_WIN32)
 return TRUE;
#endif
}

void loader_release(void) {
 // Guarantee release of the preloaded ICD libraries. This may have already been called in vkDestroyInstance.
 loader_unload_preloaded_icds();

 // release mutexes
 teardown_global_loader_settings();
 loader_platform_thread_delete_mutex(&loader_lock);
 loader_platform_thread_delete_mutex(&loader_preload_icd_lock);
}

// Preload the ICD libraries that are likely to be needed so we don't repeatedly load/unload them later
void loader_preload_icds(void) {
 loader_platform_thread_lock_mutex(&loader_preload_icd_lock);

 // Already preloaded, skip loading again.
 if (preloaded_icds.scanned_list != NULL) {
 loader_platform_thread_unlock_mutex(&loader_preload_icd_lock);
 return;
 }

 VkResult result = loader_icd_scan(NULL, &preloaded_icds, NULL, NULL);
 if (result != VK_SUCCESS) {
 loader_clear_scanned_icd_list(NULL, &preloaded_icds);
 }
 loader_platform_thread_unlock_mutex(&loader_preload_icd_lock);
}

// Release the ICD libraries that were preloaded
void loader_unload_preloaded_icds(void) {
 loader_platform_thread_lock_mutex(&loader_preload_icd_lock);
 loader_clear_scanned_icd_list(NULL, &preloaded_icds);
 loader_platform_thread_unlock_mutex(&loader_preload_icd_lock);
}

#if !defined(_WIN32)
__attribute__((constructor)) void loader_init_library(void) { loader_initialize(); }

__attribute__((destructor)) void loader_free_library(void) { loader_release(); }
#endif

// Get next file or dirname given a string list or registry key path
//
// \returns
// A pointer to first char in the next path.
// The next path (or NULL) in the list is returned in next_path.
// Note: input string is modified in some cases. PASS IN A COPY!
char *loader_get_next_path(char *path) {
 uint32_t len;
 char *next;

 if (path == NULL) return NULL;
 next = strchr(path, PATH_SEPARATOR);
 if (next == NULL) {
 len = (uint32_t)strlen(path);
 next = path + len;
 } else {
 *next = '\0';
 next++;
 }

 return next;
}

/* Processes a json manifest's library_path and the location of the json manifest to create the path of the library
 * The output is stored in out_fullpath by allocating a string - so its the caller's responsibility to free it
 * The output is the combination of the base path of manifest_file_path concatenated with library path
 * If library_path is an absolute path, we do not prepend the base path of manifest_file_path
 *
 * This function takes ownership of library_path - caller does not need to worry about freeing it.
 */
VkResult combine_manifest_directory_and_library_path(const struct loader_instance *inst, char *library_path,
 const char *manifest_file_path, char **out_fullpath) {
 assert(library_path && manifest_file_path && out_fullpath);
 if (loader_platform_is_path_absolute(library_path)) {
 *out_fullpath = library_path;
 return VK_SUCCESS;
 }
 VkResult res = VK_SUCCESS;

 size_t library_path_len = strlen(library_path);
 size_t manifest_file_path_str_len = strlen(manifest_file_path);
 bool library_path_contains_directory_symbol = false;
 for (size_t i = 0; i < library_path_len; i++) {
 if (library_path[i] == DIRECTORY_SYMBOL) {
 library_path_contains_directory_symbol = true;
 break;
 }
 }
 // Means that the library_path is neither absolute nor relative - thus we should not modify it at all
 if (!library_path_contains_directory_symbol) {
 *out_fullpath = library_path;
 return VK_SUCCESS;
 }
 // must include both a directory symbol and the null terminator
 size_t new_str_len = library_path_len + manifest_file_path_str_len + 1 + 1;

 *out_fullpath = loader_instance_heap_calloc(inst, new_str_len, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == *out_fullpath) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 size_t cur_loc_in_out_fullpath = 0;
 // look for the last occurrence of DIRECTORY_SYMBOL in manifest_file_path
 size_t last_directory_symbol = 0;
 bool found_directory_symbol = false;
 for (size_t i = 0; i < manifest_file_path_str_len; i++) {
 if (manifest_file_path[i] == DIRECTORY_SYMBOL) {
 last_directory_symbol = i + 1; // we want to include the symbol
 found_directory_symbol = true;
 // dont break because we want to find the last occurrence
 }
 }
 // Add manifest_file_path up to the last directory symbol
 if (found_directory_symbol) {
 loader_strncpy(*out_fullpath, new_str_len, manifest_file_path, last_directory_symbol);
 cur_loc_in_out_fullpath += last_directory_symbol;
 }
 loader_strncpy(&(*out_fullpath)[cur_loc_in_out_fullpath], new_str_len - cur_loc_in_out_fullpath, library_path,
 library_path_len);
 cur_loc_in_out_fullpath += library_path_len + 1;
 (*out_fullpath)[cur_loc_in_out_fullpath] = '\0';

out:
 loader_instance_heap_free(inst, library_path);

 return res;
}

// Given a filename (file) and a list of paths (in_dirs), try to find an existing
// file in the paths. If filename already is a path then no searching in the given paths.
//
// @return - A string in out_fullpath of either the full path or file.
void loader_get_fullpath(const char *file, const char *in_dirs, size_t out_size, char *out_fullpath) {
 if (!loader_platform_is_path(file) && *in_dirs) {
 size_t dirs_copy_len = strlen(in_dirs) + 1;
 char *dirs_copy = loader_stack_alloc(dirs_copy_len);
 loader_strncpy(dirs_copy, dirs_copy_len, in_dirs, dirs_copy_len);

 // find if file exists after prepending paths in given list
 // for (dir = dirs_copy; *dir && (next_dir = loader_get_next_path(dir)); dir = next_dir) {
 char *dir = dirs_copy;
 char *next_dir = loader_get_next_path(dir);
 while (*dir && next_dir) {
 int path_concat_ret = snprintf(out_fullpath, out_size, "%s%c%s", dir, DIRECTORY_SYMBOL, file);
 if (path_concat_ret < 0) {
 continue;
 }
 if (loader_platform_file_exists(out_fullpath)) {
 return;
 }
 dir = next_dir;
 next_dir = loader_get_next_path(dir);
 }
 }

 (void)snprintf(out_fullpath, out_size, "%s", file);
}

// Verify that all component layers in a meta-layer are valid.
// This function is potentially recursive so we pass in an array of "already checked" (length of the instance_layers->count) meta
// layers, preventing a stack overflow verifying meta layers that are each other's component layers
bool verify_meta_layer_component_layers(const struct loader_instance *inst, size_t prop_index,
 struct loader_layer_list *instance_layers, bool *already_checked_meta_layers) {
 struct loader_layer_properties *prop = &instance_layers->list[prop_index];
 loader_api_version meta_layer_version = loader_make_version(prop->info.specVersion);

 if (NULL == already_checked_meta_layers) {
 already_checked_meta_layers = loader_stack_alloc(sizeof(bool) * instance_layers->count);
 if (already_checked_meta_layers == NULL) {
 return false;
 }
 memset(already_checked_meta_layers, 0, sizeof(bool) * instance_layers->count);
 }

 // Mark this meta layer as 'already checked', indicating which layers have already been recursed.
 already_checked_meta_layers[prop_index] = true;

 for (uint32_t comp_layer = 0; comp_layer < prop->component_layer_names.count; comp_layer++) {
 struct loader_layer_properties *comp_prop =
 loader_find_layer_property(prop->component_layer_names.list[comp_layer], instance_layers);
 if (comp_prop == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "verify_meta_layer_component_layers: Meta-layer %s can't find component layer %s at index %d."
 " Skipping this layer.",
 prop->info.layerName, prop->component_layer_names.list[comp_layer], comp_layer);

 return false;
 }

 // Check the version of each layer, they need to be at least MAJOR and MINOR
 loader_api_version comp_prop_version = loader_make_version(comp_prop->info.specVersion);
 if (!loader_check_version_meets_required(meta_layer_version, comp_prop_version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "verify_meta_layer_component_layers: Meta-layer uses API version %d.%d, but component "
 "layer %d has API version %d.%d that is lower. Skipping this layer.",
 meta_layer_version.major, meta_layer_version.minor, comp_layer, comp_prop_version.major,
 comp_prop_version.minor);

 return false;
 }

 // Make sure the layer isn't using it's own name
 if (!strcmp(prop->info.layerName, prop->component_layer_names.list[comp_layer])) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "verify_meta_layer_component_layers: Meta-layer %s lists itself in its component layer "
 "list at index %d. Skipping this layer.",
 prop->info.layerName, comp_layer);

 return false;
 }
 if (comp_prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER) {
 size_t comp_prop_index = INT32_MAX;
 // Make sure we haven't verified this meta layer before
 for (uint32_t i = 0; i < instance_layers->count; i++) {
 if (strcmp(comp_prop->info.layerName, instance_layers->list[i].info.layerName) == 0) {
 comp_prop_index = i;
 }
 }
 if (comp_prop_index != INT32_MAX && already_checked_meta_layers[comp_prop_index]) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "verify_meta_layer_component_layers: Recursive dependency between Meta-layer %s and Meta-layer %s. "
 "Skipping this layer.",
 instance_layers->list[prop_index].info.layerName, comp_prop->info.layerName);
 return false;
 }

 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "verify_meta_layer_component_layers: Adding meta-layer %s which also contains meta-layer %s",
 prop->info.layerName, comp_prop->info.layerName);

 // Make sure if the layer is using a meta-layer in its component list that we also verify that.
 if (!verify_meta_layer_component_layers(inst, comp_prop_index, instance_layers, already_checked_meta_layers)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Meta-layer %s component layer %s can not find all component layers."
 " Skipping this layer.",
 prop->info.layerName, prop->component_layer_names.list[comp_layer]);
 return false;
 }
 }
 }
 // Didn't exit early so that means it passed all checks
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Meta-layer \"%s\" all %d component layers appear to be valid.", prop->info.layerName,
 prop->component_layer_names.count);

 // If layer logging is on, list the internals included in the meta-layer
 for (uint32_t comp_layer = 0; comp_layer < prop->component_layer_names.count; comp_layer++) {
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " [%d] %s", comp_layer, prop->component_layer_names.list[comp_layer]);
 }
 return true;
}

// Add any instance and device extensions from component layers to this layer
// list, so that anyone querying extensions will only need to look at the meta-layer
bool update_meta_layer_extensions_from_component_layers(const struct loader_instance *inst, struct loader_layer_properties *prop,
 struct loader_layer_list *instance_layers) {
 VkResult res = VK_SUCCESS;
 for (uint32_t comp_layer = 0; comp_layer < prop->component_layer_names.count; comp_layer++) {
 struct loader_layer_properties *comp_prop =
 loader_find_layer_property(prop->component_layer_names.list[comp_layer], instance_layers);

 if (NULL != comp_prop->instance_extension_list.list) {
 for (uint32_t ext = 0; ext < comp_prop->instance_extension_list.count; ext++) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0, "Meta-layer %s component layer %s adding instance extension %s",
 prop->info.layerName, prop->component_layer_names.list[comp_layer],
 comp_prop->instance_extension_list.list[ext].extensionName);

 if (!has_vk_extension_property(&comp_prop->instance_extension_list.list[ext], &prop->instance_extension_list)) {
 res = loader_add_to_ext_list(inst, &prop->instance_extension_list, 1,
 &comp_prop->instance_extension_list.list[ext]);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 return res;
 }
 }
 }
 }
 if (NULL != comp_prop->device_extension_list.list) {
 for (uint32_t ext = 0; ext < comp_prop->device_extension_list.count; ext++) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0, "Meta-layer %s component layer %s adding device extension %s",
 prop->info.layerName, prop->component_layer_names.list[comp_layer],
 comp_prop->device_extension_list.list[ext].props.extensionName);

 if (!has_vk_dev_ext_property(&comp_prop->device_extension_list.list[ext].props, &prop->device_extension_list)) {
 loader_add_to_dev_ext_list(inst, &prop->device_extension_list,
 &comp_prop->device_extension_list.list[ext].props, NULL);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 return res;
 }
 }
 }
 }
 }
 return res;
}

// Verify that all meta-layers in a layer list are valid.
VkResult verify_all_meta_layers(struct loader_instance *inst, const struct loader_envvar_all_filters *filters,
 struct loader_layer_list *instance_layers, bool *override_layer_present) {
 VkResult res = VK_SUCCESS;
 *override_layer_present = false;
 for (int32_t i = 0; i < (int32_t)instance_layers->count; i++) {
 struct loader_layer_properties *prop = &instance_layers->list[i];

 // If this is a meta-layer, make sure it is valid
 if (prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER) {
 if (verify_meta_layer_component_layers(inst, i, instance_layers, NULL)) {
 // If any meta layer is valid, update its extension list to include the extensions from its component layers.
 res = update_meta_layer_extensions_from_component_layers(inst, prop, instance_layers);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 return res;
 }
 if (prop->is_override && loader_implicit_layer_is_enabled(inst, filters, prop)) {
 *override_layer_present = true;
 }
 } else {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "Removing meta-layer %s from instance layer list since it appears invalid.", prop->info.layerName);

 loader_remove_layer_in_list(inst, instance_layers, i);
 i--;
 }
 }
 }
 return res;
}

// If the current working directory matches any app_key_path of the layers, remove all other override layers.
// Otherwise if no matching app_key was found, remove all but the global override layer, which has no app_key_path.
void remove_all_non_valid_override_layers(struct loader_instance *inst, struct loader_layer_list *instance_layers) {
 if (instance_layers == NULL) {
 return;
 }

 char cur_path[1024];
 char *ret = loader_platform_executable_path(cur_path, 1024);
 if (NULL == ret) {
 return;
 }
 // Find out if there is an override layer with same the app_key_path as the path to the current executable.
 // If more than one is found, remove it and use the first layer
 // Remove any layers which aren't global and do not have the same app_key_path as the path to the current executable.
 bool found_active_override_layer = false;
 int global_layer_index = -1;
 for (uint32_t i = 0; i < instance_layers->count; i++) {
 struct loader_layer_properties *props = &instance_layers->list[i];
 if (strcmp(props->info.layerName, VK_OVERRIDE_LAYER_NAME) == 0) {
 if (props->app_key_paths.count > 0) { // not the global layer
 for (uint32_t j = 0; j < props->app_key_paths.count; j++) {
 if (strcmp(props->app_key_paths.list[j], cur_path) == 0) {
 if (!found_active_override_layer) {
 found_active_override_layer = true;
 } else {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "remove_all_non_valid_override_layers: Multiple override layers where the same path in "
 "app_keys "
 "was found. Using the first layer found");

 // Remove duplicate active override layers that have the same app_key_path
 loader_remove_layer_in_list(inst, instance_layers, i);
 i--;
 }
 }
 }
 if (!found_active_override_layer) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "--Override layer found but not used because app \'%s\' is not in \'app_keys\' list!", cur_path);

 // Remove non-global override layers that don't have an app_key that matches cur_path
 loader_remove_layer_in_list(inst, instance_layers, i);
 i--;
 }
 } else {
 if (global_layer_index == -1) {
 global_layer_index = i;
 } else {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "remove_all_non_valid_override_layers: Multiple global override layers found. Using the first global "
 "layer found");
 loader_remove_layer_in_list(inst, instance_layers, i);
 i--;
 }
 }
 }
 }
 // Remove global layer if layer with same the app_key_path as the path to the current executable is found
 if (found_active_override_layer && global_layer_index >= 0) {
 loader_remove_layer_in_list(inst, instance_layers, global_layer_index);
 }
 // Should be at most 1 override layer in the list now.
 if (found_active_override_layer) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Using the override layer for app key %s", cur_path);
 } else if (global_layer_index >= 0) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Using the global override layer");
 }
}

/* The following are required in the "layer" object:
 * "name"
 * "type"
 * (for non-meta layers) "library_path"
 * (for meta layers) "component_layers"
 * "api_version"
 * "implementation_version"
 * "description"
 * (for implicit layers) "disable_environment"
 */

VkResult loader_read_layer_json(const struct loader_instance *inst, struct loader_layer_list *layer_instance_list,
 cJSON *layer_node, loader_api_version version, bool is_implicit, char *filename) {
 assert(layer_instance_list);
 char *library_path = NULL;
 VkResult result = VK_SUCCESS;
 struct loader_layer_properties props = {0};

 result = loader_copy_to_new_str(inst, filename, &props.manifest_file_name);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }

 // Parse name

 result = loader_parse_json_string_to_existing_str(layer_node, "name", VK_MAX_EXTENSION_NAME_SIZE, props.info.layerName);
 if (VK_ERROR_INITIALIZATION_FAILED == result) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer located at %s didn't find required layer value \"name\" in manifest JSON file, skipping this layer",
 filename);
 goto out;
 }

 // Check if this layer's name matches the override layer name, set is_override to true if so.
 if (!strcmp(props.info.layerName, VK_OVERRIDE_LAYER_NAME)) {
 props.is_override = true;
 }

 if (0 != strncmp(props.info.layerName, "VK_LAYER_", 9)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0, "Layer name %s does not conform to naming standard (Policy #LLP_LAYER_3)",
 props.info.layerName);
 }

 // Parse type
 char *type = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(layer_node, "type"));
 if (NULL == type) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer located at %s didn't find required layer value \"type\" in manifest JSON file, skipping this layer",
 filename);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // Add list entry
 if (!strcmp(type, "DEVICE")) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Device layers are deprecated. Skipping layer %s",
 props.info.layerName);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // Allow either GLOBAL or INSTANCE type interchangeably to handle layers that must work with older loaders
 if (!strcmp(type, "INSTANCE") || !strcmp(type, "GLOBAL")) {
 props.type_flags = VK_LAYER_TYPE_FLAG_INSTANCE_LAYER;
 if (!is_implicit) {
 props.type_flags |= VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER;
 }
 } else {
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // Parse api_version
 char *api_version = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(layer_node, "api_version"));
 if (NULL == api_version) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer located at %s didn't find required layer value \"api_version\" in manifest JSON file, skipping this layer",
 filename);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 props.info.specVersion = loader_parse_version_string(api_version);

 // Make sure the layer's manifest doesn't contain a non zero variant value
 if (VK_API_VERSION_VARIANT(props.info.specVersion) != 0) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Layer \"%s\" has an \'api_version\' field which contains a non-zero variant value of %d. "
 " Skipping Layer.",
 props.info.layerName, VK_API_VERSION_VARIANT(props.info.specVersion));
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // Parse implementation_version
 char *implementation_version = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(layer_node, "implementation_version"));
 if (NULL == implementation_version) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer located at %s didn't find required layer value \"implementation_version\" in manifest JSON file, "
 "skipping this layer",
 filename);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 props.info.implementationVersion = atoi(implementation_version);

 // Parse description

 result = loader_parse_json_string_to_existing_str(layer_node, "description", VK_MAX_DESCRIPTION_SIZE, props.info.description);
 if (VK_ERROR_INITIALIZATION_FAILED == result) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer located at %s didn't find required layer value \"description\" in manifest JSON file, skipping this layer",
 filename);
 goto out;
 }

 // Parse library_path

 // Library path no longer required unless component_layers is also not defined
 result = loader_parse_json_string(layer_node, "library_path", &library_path);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Skipping layer \"%s\" due to problem accessing the library_path value in the manifest JSON file",
 props.info.layerName);
 result = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 if (NULL != library_path) {
 if (NULL != loader_cJSON_GetObjectItem(layer_node, "component_layers")) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" contains meta-layer-specific component_layers, but also defining layer library path. Both are not "
 "compatible, so skipping this layer",
 props.info.layerName);
 result = VK_ERROR_INITIALIZATION_FAILED;
 loader_instance_heap_free(inst, library_path);
 goto out;
 }

 // This function takes ownership of library_path_str - so we don't need to clean it up
 result = combine_manifest_directory_and_library_path(inst, library_path, filename, &props.lib_name);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }

 // Parse component_layers

 if (NULL == library_path) {
 if (!loader_check_version_meets_required(LOADER_VERSION_1_1_0, version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" contains meta-layer-specific component_layers, but using older JSON file version.",
 props.info.layerName);
 }

 result = loader_parse_json_array_of_strings(inst, layer_node, "component_layers", &(props.component_layer_names));
 if (VK_ERROR_OUT_OF_HOST_MEMORY == result) {
 goto out;
 }
 if (VK_ERROR_INITIALIZATION_FAILED == result) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" is missing both library_path and component_layers fields. One or the other MUST be defined. "
 "Skipping this layer",
 props.info.layerName);
 goto out;
 }
 // This is now, officially, a meta-layer
 props.type_flags |= VK_LAYER_TYPE_FLAG_META_LAYER;
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Encountered meta-layer \"%s\"",
 props.info.layerName);
 }

 // Parse blacklisted_layers

 if (props.is_override) {
 result = loader_parse_json_array_of_strings(inst, layer_node, "blacklisted_layers", &(props.blacklist_layer_names));
 if (VK_ERROR_OUT_OF_HOST_MEMORY == result) {
 goto out;
 }
 }

 // Parse override_paths

 result = loader_parse_json_array_of_strings(inst, layer_node, "override_paths", &(props.override_paths));
 if (VK_ERROR_OUT_OF_HOST_MEMORY == result) {
 goto out;
 }
 if (NULL != props.override_paths.list && !loader_check_version_meets_required(loader_combine_version(1, 1, 0), version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" contains meta-layer-specific override paths, but using older JSON file version.",
 props.info.layerName);
 }

 // Parse disable_environment

 if (is_implicit) {
 cJSON *disable_environment = loader_cJSON_GetObjectItem(layer_node, "disable_environment");
 if (disable_environment == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" doesn't contain required layer object disable_environment in the manifest JSON file, skipping "
 "this layer",
 props.info.layerName);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 if (!disable_environment->child || disable_environment->child->type != cJSON_String ||
 !disable_environment->child->string || !disable_environment->child->valuestring) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Layer \"%s\" doesn't contain required child value in object disable_environment in the manifest JSON file, "
 "skipping this layer (Policy #LLP_LAYER_9)",
 props.info.layerName);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 result = loader_copy_to_new_str(inst, disable_environment->child->string, &(props.disable_env_var.name));
 if (VK_SUCCESS != result) goto out;
 result = loader_copy_to_new_str(inst, disable_environment->child->valuestring, &(props.disable_env_var.value));
 if (VK_SUCCESS != result) goto out;
 }

 // Now get all optional items and objects and put in list:
 // functions
 // instance_extensions
 // device_extensions
 // enable_environment (implicit layers only)
 // library_arch

 // Layer interface functions
 // vkGetInstanceProcAddr
 // vkGetDeviceProcAddr
 // vkNegotiateLoaderLayerInterfaceVersion (starting with JSON file 1.1.0)
 cJSON *functions = loader_cJSON_GetObjectItem(layer_node, "functions");
 if (functions != NULL) {
 if (loader_check_version_meets_required(loader_combine_version(1, 1, 0), version)) {
 result = loader_parse_json_string(functions, "vkNegotiateLoaderLayerInterfaceVersion",
 &props.functions.str_negotiate_interface);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }
 result = loader_parse_json_string(functions, "vkGetInstanceProcAddr", &props.functions.str_gipa);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;

 if (NULL == props.functions.str_negotiate_interface && props.functions.str_gipa &&
 loader_check_version_meets_required(loader_combine_version(1, 1, 0), version)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "Layer \"%s\" using deprecated \'vkGetInstanceProcAddr\' tag which was deprecated starting with JSON "
 "file version 1.1.0. The new vkNegotiateLoaderLayerInterfaceVersion function is preferred, though for "
 "compatibility reasons it may be desirable to continue using the deprecated tag.",
 props.info.layerName);
 }

 result = loader_parse_json_string(functions, "vkGetDeviceProcAddr", &props.functions.str_gdpa);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;

 if (NULL == props.functions.str_negotiate_interface && props.functions.str_gdpa &&
 loader_check_version_meets_required(loader_combine_version(1, 1, 0), version)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "Layer \"%s\" using deprecated \'vkGetDeviceProcAddr\' tag which was deprecated starting with JSON "
 "file version 1.1.0. The new vkNegotiateLoaderLayerInterfaceVersion function is preferred, though for "
 "compatibility reasons it may be desirable to continue using the deprecated tag.",
 props.info.layerName);
 }
 }

 // instance_extensions
 // array of {
 // name
 // spec_version
 // }

 cJSON *instance_extensions = loader_cJSON_GetObjectItem(layer_node, "instance_extensions");
 if (instance_extensions != NULL && instance_extensions->type == cJSON_Array) {
 cJSON *ext_item = NULL;
 cJSON_ArrayForEach(ext_item, instance_extensions) {
 if (ext_item->type != cJSON_Object) {
 continue;
 }

 VkExtensionProperties ext_prop = {0};
 result = loader_parse_json_string_to_existing_str(ext_item, "name", VK_MAX_EXTENSION_NAME_SIZE, ext_prop.extensionName);
 if (result == VK_ERROR_INITIALIZATION_FAILED) {
 continue;
 }
 char *spec_version = NULL;
 result = loader_parse_json_string(ext_item, "spec_version", &spec_version);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 if (NULL != spec_version) {
 ext_prop.specVersion = atoi(spec_version);
 }
 loader_instance_heap_free(inst, spec_version);
 bool ext_unsupported = wsi_unsupported_instance_extension(&ext_prop);
 if (!ext_unsupported) {
 result = loader_add_to_ext_list(inst, &props.instance_extension_list, 1, &ext_prop);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }
 }
 }

 // device_extensions
 // array of {
 // name
 // spec_version
 // entrypoints
 // }
 cJSON *device_extensions = loader_cJSON_GetObjectItem(layer_node, "device_extensions");
 if (device_extensions != NULL && device_extensions->type == cJSON_Array) {
 cJSON *ext_item = NULL;
 cJSON_ArrayForEach(ext_item, device_extensions) {
 if (ext_item->type != cJSON_Object) {
 continue;
 }

 VkExtensionProperties ext_prop = {0};
 result = loader_parse_json_string_to_existing_str(ext_item, "name", VK_MAX_EXTENSION_NAME_SIZE, ext_prop.extensionName);
 if (result == VK_ERROR_INITIALIZATION_FAILED) {
 continue;
 }

 char *spec_version = NULL;
 result = loader_parse_json_string(ext_item, "spec_version", &spec_version);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 if (NULL != spec_version) {
 ext_prop.specVersion = atoi(spec_version);
 }
 loader_instance_heap_free(inst, spec_version);

 cJSON *entrypoints = loader_cJSON_GetObjectItem(ext_item, "entrypoints");
 if (entrypoints == NULL) {
 result = loader_add_to_dev_ext_list(inst, &props.device_extension_list, &ext_prop, NULL);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 continue;
 }

 struct loader_string_list entrys = {0};
 result = loader_parse_json_array_of_strings(inst, ext_item, "entrypoints", &entrys);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 result = loader_add_to_dev_ext_list(inst, &props.device_extension_list, &ext_prop, &entrys);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }
 }
 if (is_implicit) {
 cJSON *enable_environment = loader_cJSON_GetObjectItem(layer_node, "enable_environment");

 // enable_environment is optional
 if (enable_environment && enable_environment->child && enable_environment->child->type == cJSON_String &&
 enable_environment->child->string && enable_environment->child->valuestring) {
 result = loader_copy_to_new_str(inst, enable_environment->child->string, &(props.enable_env_var.name));
 if (VK_SUCCESS != result) goto out;
 result = loader_copy_to_new_str(inst, enable_environment->child->valuestring, &(props.enable_env_var.value));
 if (VK_SUCCESS != result) goto out;
 }
 }

 // Read in the pre-instance stuff
 cJSON *pre_instance = loader_cJSON_GetObjectItem(layer_node, "pre_instance_functions");
 if (NULL != pre_instance) {
 // Supported versions started in 1.1.2, so anything newer
 if (!loader_check_version_meets_required(loader_combine_version(1, 1, 2), version)) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "Found pre_instance_functions section in layer from \"%s\". This section is only valid in manifest version "
 "1.1.2 or later. The section will be ignored",
 filename);
 } else if (!is_implicit) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "Found pre_instance_functions section in explicit layer from \"%s\". This section is only valid in implicit "
 "layers. The section will be ignored",
 filename);
 } else {
 result = loader_parse_json_string(pre_instance, "vkEnumerateInstanceExtensionProperties",
 &props.pre_instance_functions.enumerate_instance_extension_properties);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;

 result = loader_parse_json_string(pre_instance, "vkEnumerateInstanceLayerProperties",
 &props.pre_instance_functions.enumerate_instance_layer_properties);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;

 result = loader_parse_json_string(pre_instance, "vkEnumerateInstanceVersion",
 &props.pre_instance_functions.enumerate_instance_version);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }
 }

 if (loader_cJSON_GetObjectItem(layer_node, "app_keys")) {
 if (!props.is_override) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Layer %s contains app_keys, but any app_keys can only be provided by the override meta layer. "
 "These will be ignored.",
 props.info.layerName);
 }

 result = loader_parse_json_array_of_strings(inst, layer_node, "app_keys", &props.app_key_paths);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) goto out;
 }

 char *library_arch = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(layer_node, "library_arch"));
 if (NULL != library_arch) {
 if ((strncmp(library_arch, "32", 2) == 0 && sizeof(void *) != 4) ||
 (strncmp(library_arch, "64", 2) == 0 && sizeof(void *) != 8)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "The library architecture in layer %s doesn't match the current running architecture, skipping this layer",
 filename);
 result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 }

 result = VK_SUCCESS;

out:
 // Try to append the layer property
 if (VK_SUCCESS == result) {
 result = loader_append_layer_property(inst, layer_instance_list, &props);
 }
 // If appending fails - free all the memory allocated in it
 if (VK_SUCCESS != result) {
 loader_free_layer_properties(inst, &props);
 }
 return result;
}

bool is_valid_layer_json_version(const loader_api_version *layer_json) {
 // Supported versions are: 1.0.0, 1.0.1, 1.1.0 - 1.1.2, and 1.2.0 - 1.2.1.
 if ((layer_json->major == 1 && layer_json->minor == 2 && layer_json->patch < 2) ||
 (layer_json->major == 1 && layer_json->minor == 1 && layer_json->patch < 3) ||
 (layer_json->major == 1 && layer_json->minor == 0 && layer_json->patch < 2)) {
 return true;
 }
 return false;
}

// Given a cJSON struct (json) of the top level JSON object from layer manifest
// file, add entry to the layer_list. Fill out the layer_properties in this list
// entry from the input cJSON object.
//
// \returns
// void
// layer_list has a new entry and initialized accordingly.
// If the json input object does not have all the required fields no entry
// is added to the list.
VkResult loader_add_layer_properties(const struct loader_instance *inst, struct loader_layer_list *layer_instance_list, cJSON *json,
 bool is_implicit, char *filename) {
 // The following Fields in layer manifest file that are required:
 // - "file_format_version"
 // - If more than one "layer" object are used, then the "layers" array is
 // required
 VkResult result = VK_ERROR_INITIALIZATION_FAILED;
 // Make sure sure the top level json value is an object
 if (!json || json->type != cJSON_Object) {
 goto out;
 }
 char *file_vers = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(json, "file_format_version"));
 if (NULL == file_vers) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: Manifest %s missing required field file_format_version", filename);
 goto out;
 }

 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0, "Found manifest file %s (file version %s)", filename, file_vers);
 // Get the major/minor/and patch as integers for easier comparison
 loader_api_version json_version = loader_make_full_version(loader_parse_version_string(file_vers));

 if (!is_valid_layer_json_version(&json_version)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: %s has unknown layer manifest file version %d.%d.%d. May cause errors.", filename,
 json_version.major, json_version.minor, json_version.patch);
 }

 // If "layers" is present, read in the array of layer objects
 cJSON *layers_node = loader_cJSON_GetObjectItem(json, "layers");
 if (layers_node != NULL) {
 // Supported versions started in 1.0.1, so anything newer
 if (!loader_check_version_meets_required(loader_combine_version(1, 0, 1), json_version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: \'layers\' tag not supported until file version 1.0.1, but %s is reporting "
 "version %s",
 filename, file_vers);
 }
 cJSON *layer_node = NULL;
 cJSON_ArrayForEach(layer_node, layers_node) {
 if (layer_node->type != cJSON_Object) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: Array element in \"layers\" field in manifest JSON file %s is not an object. "
 "Skipping this file",
 filename);
 goto out;
 }
 result = loader_read_layer_json(inst, layer_instance_list, layer_node, json_version, is_implicit, filename);
 }
 } else {
 // Otherwise, try to read in individual layers
 cJSON *layer_node = loader_cJSON_GetObjectItem(json, "layer");
 if (layer_node == NULL) {
 // Don't warn if this happens to be an ICD manifest
 if (loader_cJSON_GetObjectItem(json, "ICD") == NULL) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: Can not find 'layer' object in manifest JSON file %s. Skipping this file.",
 filename);
 }
 goto out;
 }
 // Loop through all "layer" objects in the file to get a count of them
 // first.
 uint16_t layer_count = 0;
 cJSON *tempNode = layer_node;
 do {
 tempNode = tempNode->next;
 layer_count++;
 } while (tempNode != NULL);

 // Throw a warning if we encounter multiple "layer" objects in file
 // versions newer than 1.0.0. Having multiple objects with the same
 // name at the same level is actually a JSON standard violation.
 if (layer_count > 1 && loader_check_version_meets_required(loader_combine_version(1, 0, 1), json_version)) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_add_layer_properties: Multiple 'layer' nodes are deprecated starting in file version \"1.0.1\". "
 "Please use 'layers' : [] array instead in %s.",
 filename);
 } else {
 do {
 result = loader_read_layer_json(inst, layer_instance_list, layer_node, json_version, is_implicit, filename);
 layer_node = layer_node->next;
 } while (layer_node != NULL);
 }
 }

out:

 return result;
}

VkResult copy_data_file_info(const struct loader_instance *inst, const char *cur_path, const char *relative_path,
 size_t relative_path_size, struct loader_string_list *search_paths) {
 if (NULL != cur_path) {
 uint32_t start = 0;
 uint32_t stop = 0;

 while (cur_path[start] != '\0') {
 while (cur_path[start] == PATH_SEPARATOR && cur_path[start] != '\0') {
 start++;
 }
 stop = start;
 while (cur_path[stop] != PATH_SEPARATOR && cur_path[stop] != '\0') {
 stop++;
 }
 const size_t s = stop - start;
 if (s) {
 // space enough for base path, relative path, path separator, and null terminator
 size_t new_str_len = s + relative_path_size + 2;

 char *new_str = loader_instance_heap_calloc(inst, new_str_len, VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_str) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 memcpy(new_str, &cur_path[start], s);
 new_str[s] = '\0';

 // If this is a specific JSON file, just add it and don't add any
 // relative path or directory symbol to it.
 if (!is_json(new_str, s)) {
 // Add the relative directory if present.
 if (relative_path_size > 0) {
 char *rel_start = new_str + s;

 // If last symbol written was not a directory symbol, add it.
 if (*(rel_start - 1) != DIRECTORY_SYMBOL) {
 *rel_start++ = DIRECTORY_SYMBOL;
 }
 memcpy(rel_start, relative_path, relative_path_size);
 rel_start[relative_path_size] = '\0';
 }
 }

 VkResult res = append_str_to_string_list_if_unique(inst, search_paths, new_str);
 if (VK_SUCCESS != res) {
 return res;
 }
 start = stop;
 }
 }
 }
 return VK_SUCCESS;
}

// If the file found is a manifest file name, add it to the end of out_files manifest list.
VkResult add_if_manifest_file(const struct loader_instance *inst, const char *file_name, struct loader_string_list *out_files) {
 assert(NULL != file_name && "add_if_manifest_file: Received NULL pointer for file_name");
 assert(NULL != out_files && "add_if_manifest_file: Received NULL pointer for out_files");

 // Look for files ending with ".json" suffix
 size_t name_len = strlen(file_name);
 if (!is_json(file_name, name_len)) {
 // Use incomplete to indicate invalid name, but to keep going.
 return VK_INCOMPLETE;
 }

 return copy_str_to_string_list(inst, out_files, file_name, name_len);
}

// If the file found is a manifest file name, add it to the start of the out_files manifest list.
VkResult prepend_if_manifest_file(const struct loader_instance *inst, const char *file_name, struct loader_string_list *out_files) {
 assert(NULL != file_name && "prepend_if_manifest_file: Received NULL pointer for file_name");
 assert(NULL != out_files && "prepend_if_manifest_file: Received NULL pointer for out_files");

 // Look for files ending with ".json" suffix
 size_t name_len = strlen(file_name);
 if (!is_json(file_name, name_len)) {
 // Use incomplete to indicate invalid name, but to keep going.
 return VK_INCOMPLETE;
 }

 return copy_str_to_start_of_string_list(inst, out_files, file_name, name_len);
}

// Iterate all strings in search_paths and add any files found. If any path in the search path points to a specific JSON, attempt
// to only open that one JSON. Otherwise, if the path is a folder, search the folder for JSON files.
VkResult add_data_files(const struct loader_instance *inst, struct loader_string_list *search_paths,
 struct loader_string_list *out_files) {
 VkResult vk_result = VK_SUCCESS;
 char full_path[2048];
#if !defined(_WIN32)
 char temp_path[2048];
#endif

 for (size_t i = 0; i < search_paths->count; i++) {
 // Now, parse the paths
 char *next_file = search_paths->list[i];
 while (NULL != next_file && *next_file != '\0') {
 char *name = NULL;
 char *cur_file = next_file;
 next_file = loader_get_next_path(cur_file);

 // Is this a JSON file, then try to open it.
 size_t len = strlen(cur_file);
 if (is_json(cur_file, len)) {
#if defined(_WIN32)
 name = cur_file;
#elif COMMON_UNIX_PLATFORMS
 // Only Linux has relative paths, make a copy of location so it isn't modified
 size_t str_len;
 if (NULL != next_file) {
 str_len = next_file - cur_file + 1;
 } else {
 str_len = strlen(cur_file) + 1;
 }
 if (str_len > sizeof(temp_path)) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0, "add_data_files: Path to %s too long", cur_file);
 continue;
 }
 strncpy(temp_path, cur_file, str_len);
 name = temp_path;
#else
#warning add_data_files must define relative path copy for this platform
#endif
 loader_get_fullpath(cur_file, name, sizeof(full_path), full_path);
 name = full_path;

 VkResult local_res;
 local_res = add_if_manifest_file(inst, name, out_files);

 // Incomplete means this was not a valid data file.
 if (local_res == VK_INCOMPLETE) {
 continue;
 } else if (local_res != VK_SUCCESS) {
 vk_result = local_res;
 break;
 }
 } else { // Otherwise, treat it as a directory
 DIR *dir_stream = loader_opendir(inst, cur_file);
 if (NULL == dir_stream) {
 continue;
 }
 while (1) {
 errno = 0;
 struct dirent *dir_entry = readdir(dir_stream);
#if !defined(WIN32) // Windows doesn't use readdir, don't check errors on functions which aren't called
 if (errno != 0) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "readdir failed with %d: %s", errno, strerror(errno));
 break;
 }
#endif
 if (NULL == dir_entry) {
 break;
 }

 name = &(dir_entry->d_name[0]);
 loader_get_fullpath(name, cur_file, sizeof(full_path), full_path);
 name = full_path;

 VkResult local_res;
 local_res = add_if_manifest_file(inst, name, out_files);

 // Incomplete means this was not a valid data file.
 if (local_res == VK_INCOMPLETE) {
 continue;
 } else if (local_res != VK_SUCCESS) {
 vk_result = local_res;
 break;
 }
 }
 loader_closedir(inst, dir_stream);
 if (vk_result != VK_SUCCESS) {
 goto out;
 }
 }
 }
 }

out:

 return vk_result;
}

// Look for data files in the provided paths, but first check the environment override to determine if we should use that
// instead.
VkResult read_data_files_in_search_paths(const struct loader_instance *inst, enum loader_data_files_type manifest_type,
 const struct loader_string_list *path_overrides, bool *override_active,
 struct loader_string_list *out_files) {
 VkResult vk_result = VK_SUCCESS;
 char *override_env = NULL;
 char *additional_env = NULL;
 struct loader_string_list search_paths = {0};

#if COMMON_UNIX_PLATFORMS
 const char *relative_location = NULL; // Only used on unix platforms
 size_t rel_size = 0; // unused in windows, dont declare so no compiler warnings are generated
#endif

#if defined(__APPLE__)
 char *bundle_path = NULL;
#endif

#if defined(_WIN32)
 char *package_path = NULL;
#elif COMMON_UNIX_PLATFORMS
 // Determine how much space is needed to generate the full search path
 // for the current manifest files.
 char *xdg_config_home = loader_secure_getenv("XDG_CONFIG_HOME", inst);
 char *xdg_config_dirs = loader_secure_getenv("XDG_CONFIG_DIRS", inst);

#if !defined(__Fuchsia__) && !defined(__QNX__)
 if (NULL == xdg_config_dirs || '\0' == xdg_config_dirs[0]) {
 xdg_config_dirs = FALLBACK_CONFIG_DIRS;
 }
#endif

 char *xdg_data_home = loader_secure_getenv("XDG_DATA_HOME", inst);
 char *xdg_data_dirs = loader_secure_getenv("XDG_DATA_DIRS", inst);

#if !defined(__Fuchsia__) && !defined(__QNX__)
 if (NULL == xdg_data_dirs || '\0' == xdg_data_dirs[0]) {
 xdg_data_dirs = FALLBACK_DATA_DIRS;
 }
#endif

 char *home = NULL;
 char *default_data_home = NULL;
 char *default_config_home = NULL;
 char *home_data_dir = NULL;
 char *home_config_dir = NULL;

 // Only use HOME if XDG_DATA_HOME is not present on the system
 home = loader_secure_getenv("HOME", inst);
 if (home != NULL) {
 if (NULL == xdg_config_home || '\0' == xdg_config_home[0]) {
 const char config_suffix[] = "/.config";
 size_t default_config_home_len = strlen(home) + sizeof(config_suffix) + 1;
 default_config_home = loader_instance_heap_calloc(inst, default_config_home_len, VK_SYSTEM_ALLOCATION_SCOPE_COMMAND);
 if (default_config_home == NULL) {
 vk_result = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 strncpy(default_config_home, home, default_config_home_len);
 strncat(default_config_home, config_suffix, default_config_home_len);
 }
 if (NULL == xdg_data_home || '\0' == xdg_data_home[0]) {
 const char data_suffix[] = "/.local/share";
 size_t default_data_home_len = strlen(home) + sizeof(data_suffix) + 1;
 default_data_home = loader_instance_heap_calloc(inst, default_data_home_len, VK_SYSTEM_ALLOCATION_SCOPE_COMMAND);
 if (default_data_home == NULL) {
 vk_result = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 strncpy(default_data_home, home, default_data_home_len);
 strncat(default_data_home, data_suffix, default_data_home_len);
 }
 }

 if (NULL != default_config_home) {
 home_config_dir = default_config_home;
 } else {
 home_config_dir = xdg_config_home;
 }
 if (NULL != default_data_home) {
 home_data_dir = default_data_home;
 } else {
 home_data_dir = xdg_data_home;
 }
#else
#warning read_data_files_in_search_paths unsupported platform
#endif

 switch (manifest_type) {
 case LOADER_DATA_FILE_MANIFEST_DRIVER:
 if (loader_settings_should_use_driver_environment_variables(inst)) {
 override_env = loader_secure_getenv(VK_DRIVER_FILES_ENV_VAR, inst);
 if (NULL == override_env) {
 // Not there, so fall back to the old name
 override_env = loader_secure_getenv(VK_ICD_FILENAMES_ENV_VAR, inst);
 }
 additional_env = loader_secure_getenv(VK_ADDITIONAL_DRIVER_FILES_ENV_VAR, inst);
 }
#if COMMON_UNIX_PLATFORMS
 relative_location = VK_DRIVERS_INFO_RELATIVE_DIR;
#endif
#if defined(_WIN32)
 package_path = windows_get_app_package_manifest_path(inst);
#endif
 break;
 case LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER:
 override_env = loader_secure_getenv(VK_IMPLICIT_LAYER_PATH_ENV_VAR, inst);
 additional_env = loader_secure_getenv(VK_ADDITIONAL_IMPLICIT_LAYER_PATH_ENV_VAR, inst);
#if COMMON_UNIX_PLATFORMS
 relative_location = VK_ILAYERS_INFO_RELATIVE_DIR;
#endif
#if defined(_WIN32)
 package_path = windows_get_app_package_manifest_path(inst);
#endif
 break;
 case LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER:
 override_env = loader_secure_getenv(VK_EXPLICIT_LAYER_PATH_ENV_VAR, inst);
 additional_env = loader_secure_getenv(VK_ADDITIONAL_EXPLICIT_LAYER_PATH_ENV_VAR, inst);
#if COMMON_UNIX_PLATFORMS
 relative_location = VK_ELAYERS_INFO_RELATIVE_DIR;
#endif
 break;
 default:
 assert(false && "Shouldn't get here!");
 break;
 }

 // Log a message when VK_LAYER_PATH is set but the override layer paths take priority
 if (manifest_type == LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER &&
 (NULL != override_env && NULL != path_overrides && path_overrides->count > 0)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Ignoring VK_LAYER_PATH. The Override layer is active and has override paths set, which takes priority. "
 "VK_LAYER_PATH is set to %s",
 override_env);
 }

 // Add the remaining paths to the list
 if (NULL != path_overrides && path_overrides->count > 0) {
 for (size_t i = 0; i < path_overrides->count; i++) {
 if (NULL != path_overrides->list[i]) {
 if (manifest_type == LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "%s", path_overrides->list[i]);
 }
 vk_result = copy_data_file_info(inst, path_overrides->list[i], NULL, 0, &search_paths);
 if (vk_result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }
 }
 } else if (override_env != NULL) {
 vk_result = copy_data_file_info(inst, override_env, NULL, 0, &search_paths);
 if (vk_result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 } else {
 // Add any additional search paths defined in the additive environment variable
 if (NULL != additional_env) {
 vk_result = copy_data_file_info(inst, additional_env, NULL, 0, &search_paths);
 if (vk_result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }

#if defined(_WIN32)
 if (NULL != package_path) {
 vk_result = copy_data_file_info(inst, package_path, NULL, 0, &search_paths);
 if (vk_result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }
#elif COMMON_UNIX_PLATFORMS
 rel_size = strlen(relative_location);
 if (rel_size > 0) {
#if defined(__APPLE__)
 // Add the bundle's Resources dir to the beginning of the search path.
 // Looks for manifests in the bundle first, before any system directories.
 // This also appears to work unmodified for iOS, it finds the app bundle on the devices
 // file system. (RSW)
 CFBundleRef main_bundle = CFBundleGetMainBundle();
 if (NULL != main_bundle) {
 CFURLRef ref = CFBundleCopyResourcesDirectoryURL(main_bundle);
 if (NULL != ref) {
 // Allocate large scratch buffer to hold the bundles path, the relative location inside the bundle, plus a path
 // separator and null terminator. Since we are using a while loop, initialize length with half the intended size
 size_t bundle_path_len = (MAXPATHLEN + rel_size + 2) / 2;
 bool bundle_query_success = false;
 uint32_t retry_count = 0;
 while (!bundle_query_success && retry_count < 4) {
 void *new_bundle_path = loader_instance_heap_realloc(
 inst, bundle_path, bundle_path_len, bundle_path_len * 2, VK_SYSTEM_ALLOCATION_SCOPE_COMMAND);
 if (NULL == new_bundle_path) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "read_data_files_in_search_paths: Failed to allocate space for bundle path of length %d",
 (uint32_t)bundle_path_len * 2);
 vk_result = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 bundle_path = new_bundle_path;
 bundle_path_len = bundle_path_len * 2;
 memset(bundle_path, 0, bundle_path_len);
 bundle_query_success = CFURLGetFileSystemRepresentation(ref, TRUE, (UInt8 *)bundle_path, bundle_path_len);
 retry_count++;
 }

 if (bundle_query_success) {
 size_t cur_bundle_len = strlen(bundle_path);

 if (cur_bundle_len + rel_size + 2 > bundle_path_len) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "read_data_files_in_search_paths: bundle_path %s of size %d does not have enough space to "
 "append relative_path",
 bundle_path, (uint32_t)bundle_path_len);
 vk_result = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 bundle_path[cur_bundle_len] = DIRECTORY_SYMBOL;
 cur_bundle_len++;
 memcpy(bundle_path + cur_bundle_len, relative_location, rel_size);
 cur_bundle_len += rel_size;
 bundle_path[cur_bundle_len] = '\0';

 vk_result = copy_data_file_info(inst, bundle_path, NULL, 0, &search_paths);
 if (vk_result == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }
 CFRelease(ref);
 }
 }
#endif // __APPLE__

 // Only add the home folders if not NULL
 if (NULL != home_config_dir) {
 vk_result = copy_data_file_info(inst, home_config_dir, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
 }
 vk_result = copy_data_file_info(inst, xdg_config_dirs, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
 vk_result = copy_data_file_info(inst, SYSCONFDIR, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
#if defined(EXTRASYSCONFDIR)
 vk_result = copy_data_file_info(inst, EXTRASYSCONFDIR, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
#endif

 // Only add the home folders if not NULL
 if (NULL != home_data_dir) {
 vk_result = copy_data_file_info(inst, home_data_dir, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
 }
 vk_result = copy_data_file_info(inst, xdg_data_dirs, relative_location, rel_size, &search_paths);
 if (VK_SUCCESS != vk_result) {
 goto out;
 }
 }
#else
#warning read_data_files_in_search_paths unsupported platform
#endif
 }

 // Print out the paths being searched if debugging is enabled
 uint32_t log_flags = 0;

 if (manifest_type == LOADER_DATA_FILE_MANIFEST_DRIVER) {
 log_flags = VULKAN_LOADER_DRIVER_BIT;
 loader_log(inst, VULKAN_LOADER_DRIVER_BIT, 0, "Searching for driver manifest files");
 } else {
 log_flags = VULKAN_LOADER_LAYER_BIT;
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, "Searching for %s layer manifest files",
 manifest_type == LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER ? "explicit" : "implicit");
 }
 loader_log(inst, log_flags, 0, " In following locations:");

 for (size_t i = 0; i < search_paths.count; i++) {
 loader_log(inst, log_flags, 0, " %s", search_paths.list[i]);
 }

 // Now, parse the paths and add any manifest files found in them.
 vk_result = add_data_files(inst, &search_paths, out_files);

 if (log_flags != 0 && out_files->count > 0) {
 loader_log(inst, log_flags, 0, " Found the following files:");
 for (uint32_t cur_file = 0; cur_file < out_files->count; ++cur_file) {
 loader_log(inst, log_flags, 0, " %s", out_files->list[cur_file]);
 }
 } else {
 loader_log(inst, log_flags, 0, " Found no files");
 }

 if ((NULL != path_overrides && path_overrides->count > 0) || NULL != override_env) {
 *override_active = true;
 } else {
 *override_active = false;
 }

out:

 loader_free_getenv(additional_env, inst);
 loader_free_getenv(override_env, inst);
#if defined(_WIN32)
 loader_instance_heap_free(inst, package_path);
#elif COMMON_UNIX_PLATFORMS
#if defined(__APPLE__)
 loader_instance_heap_free(inst, bundle_path);
#endif
 loader_free_getenv(xdg_config_home, inst);
 loader_free_getenv(xdg_config_dirs, inst);
 loader_free_getenv(xdg_data_home, inst);
 loader_free_getenv(xdg_data_dirs, inst);
 loader_free_getenv(xdg_data_home, inst);
 loader_free_getenv(home, inst);
 loader_instance_heap_free(inst, default_data_home);
 loader_instance_heap_free(inst, default_config_home);
#else
#warning read_data_files_in_search_paths unsupported platform
#endif

 free_string_list(inst, &search_paths);

 return vk_result;
}

// Find the Vulkan library manifest files.
//
// This function scans the appropriate locations for a list of JSON manifest files based on the
// "manifest_type". The location is interpreted as Registry path on Windows and a directory path(s)
// on Linux.
// "home_location" is an additional directory in the users home directory to look at. It is
// expanded into the dir path $XDG_DATA_HOME/home_location or $HOME/.local/share/home_location
// depending on environment variables. This "home_location" is only used on Linux.
//
// \returns
// VKResult
// A string list of manifest files to be opened in out_files param.
// List has a pointer to string for each manifest filename.
// When done using the list in out_files, pointers should be freed.
// Location or override string lists can be either files or directories as
// follows:
// | location | override
// --------------------------------
// Win ICD | files | files
// Win Layer | files | dirs
// Linux ICD | dirs | files
// Linux Layer| dirs | dirs

VkResult loader_get_data_files(const struct loader_instance *inst, enum loader_data_files_type manifest_type,
 const struct loader_string_list *path_overrides, struct loader_string_list *out_files) {
 VkResult res = VK_SUCCESS;
 bool override_active = false;

 // Free and init the out_files information so there's no false data left from uninitialized variables.
 free_string_list(inst, out_files);

 res = read_data_files_in_search_paths(inst, manifest_type, path_overrides, &override_active, out_files);
 if (VK_SUCCESS != res) {
 goto out;
 }

#if defined(_WIN32)
 // Read the registry if the override wasn't active.
 if (!override_active) {
 bool warn_if_not_present = false;
 char *registry_location = NULL;

 switch (manifest_type) {
 default:
 goto out;
 case LOADER_DATA_FILE_MANIFEST_DRIVER:
 warn_if_not_present = true;
 registry_location = VK_DRIVERS_INFO_REGISTRY_LOC;
 break;
 case LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER:
 registry_location = VK_ILAYERS_INFO_REGISTRY_LOC;
 break;
 case LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER:
 warn_if_not_present = true;
 registry_location = VK_ELAYERS_INFO_REGISTRY_LOC;
 break;
 }
 VkResult tmp_res =
 windows_read_data_files_in_registry(inst, manifest_type, warn_if_not_present, registry_location, out_files);
 // Only return an error if there was an error this time, and no manifest files from before.
 if (VK_SUCCESS != tmp_res && out_files->count == 0) {
 res = tmp_res;
 goto out;
 }
 }
#endif

out:

 if (VK_SUCCESS != res) {
 free_string_list(inst, out_files);
 }

 return res;
}

struct ICDManifestInfo {
 char *full_library_path;
 uint32_t version;
};

// Takes a json file, opens, reads, and parses an ICD Manifest out of it.
// Should only return VK_SUCCESS, VK_ERROR_INCOMPATIBLE_DRIVER, or VK_ERROR_OUT_OF_HOST_MEMORY
VkResult loader_parse_icd_manifest(const struct loader_instance *inst, char *file_str, struct ICDManifestInfo *icd,
 bool *skipped_portability_drivers) {
 VkResult res = VK_SUCCESS;
 cJSON *icd_manifest_json = NULL;

 if (file_str == NULL) {
 goto out;
 }

 res = loader_get_json(inst, file_str, &icd_manifest_json);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 if (res != VK_SUCCESS || NULL == icd_manifest_json) {
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 cJSON *file_format_version_json = loader_cJSON_GetObjectItem(icd_manifest_json, "file_format_version");
 if (file_format_version_json == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: ICD JSON %s does not have a \'file_format_version\' field. Skipping ICD JSON.",
 file_str);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 char *file_vers_str = loader_cJSON_GetStringValue(file_format_version_json);
 if (NULL == file_vers_str) {
 // Only reason the print can fail is if there was an allocation issue
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Failed retrieving ICD JSON %s \'file_format_version\' field. Skipping ICD JSON",
 file_str);
 goto out;
 }
 loader_log(inst, VULKAN_LOADER_DRIVER_BIT, 0, "Found ICD manifest file %s, version %s", file_str, file_vers_str);

 // Get the version of the driver manifest
 loader_api_version json_file_version = loader_make_full_version(loader_parse_version_string(file_vers_str));

 // Loader only knows versions 1.0.0 and 1.0.1, anything above it is unknown
 if (loader_check_version_meets_required(loader_combine_version(1, 0, 2), json_file_version)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: %s has unknown icd manifest file version %d.%d.%d. May cause errors.", file_str,
 json_file_version.major, json_file_version.minor, json_file_version.patch);
 }

 cJSON *itemICD = loader_cJSON_GetObjectItem(icd_manifest_json, "ICD");
 if (itemICD == NULL) {
 // Don't warn if this happens to be a layer manifest file
 if (loader_cJSON_GetObjectItem(icd_manifest_json, "layer") == NULL &&
 loader_cJSON_GetObjectItem(icd_manifest_json, "layers") == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Can not find \'ICD\' object in ICD JSON file %s. Skipping ICD JSON", file_str);
 }
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 cJSON *library_path_json = loader_cJSON_GetObjectItem(itemICD, "library_path");
 if (library_path_json == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Failed to find \'library_path\' object in ICD JSON file %s. Skipping ICD JSON.",
 file_str);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 bool out_of_memory = false;
 char *library_path = loader_cJSON_Print(library_path_json, &out_of_memory);
 if (out_of_memory) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Failed retrieving ICD JSON %s \'library_path\' field. Skipping ICD JSON.", file_str);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 } else if (!library_path || strlen(library_path) == 0) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: ICD JSON %s \'library_path\' field is empty. Skipping ICD JSON.", file_str);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 loader_instance_heap_free(inst, library_path);
 goto out;
 }

 // Print out the paths being searched if debugging is enabled
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_DRIVER_BIT, 0, "Searching for ICD drivers named %s", library_path);
 // This function takes ownership of library_path - so we don't need to clean it up
 res = combine_manifest_directory_and_library_path(inst, library_path, file_str, &icd->full_library_path);
 if (VK_SUCCESS != res) {
 goto out;
 }

 cJSON *api_version_json = loader_cJSON_GetObjectItem(itemICD, "api_version");
 if (api_version_json == NULL) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: ICD JSON %s does not have an \'api_version\' field. Skipping ICD JSON.", file_str);
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 char *version_str = loader_cJSON_GetStringValue(api_version_json);
 if (NULL == version_str) {
 // Only reason the print can fail is if there was an allocation issue
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Failed retrieving ICD JSON %s \'api_version\' field. Skipping ICD JSON.", file_str);

 goto out;
 }
 icd->version = loader_parse_version_string(version_str);

 if (VK_API_VERSION_VARIANT(icd->version) != 0) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_parse_icd_manifest: Driver's ICD JSON %s \'api_version\' field contains a non-zero variant value of %d. "
 " Skipping ICD JSON.",
 file_str, VK_API_VERSION_VARIANT(icd->version));
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 // Skip over ICD's which contain a true "is_portability_driver" value whenever the application doesn't enable
 // portability enumeration.
 cJSON *is_portability_driver_json = loader_cJSON_GetObjectItem(itemICD, "is_portability_driver");
 if (loader_cJSON_IsTrue(is_portability_driver_json) && inst && !inst->portability_enumeration_enabled) {
 if (skipped_portability_drivers) {
 *skipped_portability_drivers = true;
 }
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }

 char *library_arch_str = loader_cJSON_GetStringValue(loader_cJSON_GetObjectItem(itemICD, "library_arch"));
 if (library_arch_str != NULL) {
 if ((strncmp(library_arch_str, "32", 2) == 0 && sizeof(void *) != 4) ||
 (strncmp(library_arch_str, "64", 2) == 0 && sizeof(void *) != 8)) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "loader_parse_icd_manifest: Driver library architecture doesn't match the current running "
 "architecture, skipping this driver");
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 goto out;
 }
 }
out:
 loader_cJSON_Delete(icd_manifest_json);
 return res;
}

// Try to find the Vulkan ICD driver(s).
//
// This function scans the default system loader path(s) or path specified by either the
// VK_DRIVER_FILES or VK_ICD_FILENAMES environment variable in order to find loadable
// VK ICDs manifest files.
// From these manifest files it finds the ICD libraries.
//
// skipped_portability_drivers is used to report whether the loader found drivers which report
// portability but the application didn't enable the bit to enumerate them
// Can be NULL
//
// \returns
// Vulkan result
// (on result == VK_SUCCESS) a list of icds that were discovered
VkResult loader_icd_scan(const struct loader_instance *inst, struct loader_icd_tramp_list *icd_tramp_list,
 const VkInstanceCreateInfo *pCreateInfo, bool *skipped_portability_drivers) {
 VkResult res = VK_SUCCESS;
 struct loader_string_list manifest_files = {0};
 struct loader_envvar_filter select_filter = {0};
 struct loader_envvar_filter disable_filter = {0};
 struct ICDManifestInfo *icd_details = NULL;

 // Set up the ICD Trampoline list so elements can be written into it.
 res = loader_init_scanned_icd_list(inst, icd_tramp_list);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }

 bool direct_driver_loading_exclusive_mode = false;
 res = loader_scan_for_direct_drivers(inst, pCreateInfo, icd_tramp_list, &direct_driver_loading_exclusive_mode);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 if (direct_driver_loading_exclusive_mode) {
 // Make sure to jump over the system & env-var driver discovery mechanisms if exclusive mode is set, even if no drivers
 // were successfully found through the direct driver loading mechanism
 goto out;
 }

 if (loader_settings_should_use_driver_environment_variables(inst)) {
 // Parse the filter environment variables to determine if we have any special behavior
 res = parse_generic_filter_environment_var(inst, VK_DRIVERS_SELECT_ENV_VAR, &select_filter);
 if (VK_SUCCESS != res) {
 goto out;
 }
 res = parse_generic_filter_environment_var(inst, VK_DRIVERS_DISABLE_ENV_VAR, &disable_filter);
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 // Get a list of manifest files for ICDs
 res = loader_get_data_files(inst, LOADER_DATA_FILE_MANIFEST_DRIVER, NULL, &manifest_files);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Add any drivers provided by the loader settings file
 res = loader_settings_get_additional_driver_files(inst, &manifest_files);
 if (VK_SUCCESS != res) {
 goto out;
 }

 icd_details = loader_stack_alloc(sizeof(struct ICDManifestInfo) * manifest_files.count);
 if (NULL == icd_details) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 memset(icd_details, 0, sizeof(struct ICDManifestInfo) * manifest_files.count);

 for (uint32_t i = 0; i < manifest_files.count; i++) {
 VkResult icd_res = VK_SUCCESS;

 icd_res = loader_parse_icd_manifest(inst, manifest_files.list[i], &icd_details[i], skipped_portability_drivers);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == icd_res) {
 res = icd_res;
 goto out;
 } else if (VK_ERROR_INCOMPATIBLE_DRIVER == icd_res) {
 continue;
 }

 if (select_filter.count > 0 || disable_filter.count > 0) {
 // Get only the filename for comparing to the filters
 char *just_filename_str = strrchr(manifest_files.list[i], DIRECTORY_SYMBOL);

 // No directory symbol, just the filename
 if (NULL == just_filename_str) {
 just_filename_str = manifest_files.list[i];
 } else {
 just_filename_str++;
 }

 bool name_matches_select =
 (select_filter.count > 0 && check_name_matches_filter_environment_var(just_filename_str, &select_filter));
 bool name_matches_disable =
 (disable_filter.count > 0 && check_name_matches_filter_environment_var(just_filename_str, &disable_filter));

 if (name_matches_disable && !name_matches_select) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "Driver \"%s\" ignored because it was disabled by env var \'%s\'", just_filename_str,
 VK_DRIVERS_DISABLE_ENV_VAR);
 continue;
 }
 if (select_filter.count != 0 && !name_matches_select) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "Driver \"%s\" ignored because not selected by env var \'%s\'", just_filename_str,
 VK_DRIVERS_SELECT_ENV_VAR);
 continue;
 }
 }

 enum loader_layer_library_status lib_status;
 icd_res =
 loader_scanned_icd_add(inst, icd_tramp_list, icd_details[i].full_library_path, icd_details[i].version, &lib_status);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == icd_res) {
 res = icd_res;
 goto out;
 } else if (VK_ERROR_INCOMPATIBLE_DRIVER == icd_res) {
 switch (lib_status) {
 case LOADER_LAYER_LIB_NOT_LOADED:
 case LOADER_LAYER_LIB_ERROR_FAILED_TO_LOAD:
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "loader_icd_scan: Failed loading library associated with ICD JSON %s. Ignoring this JSON",
 icd_details[i].full_library_path);
 break;
 case LOADER_LAYER_LIB_ERROR_WRONG_BIT_TYPE: {
 loader_log(inst, VULKAN_LOADER_DRIVER_BIT, 0, "Requested ICD %s was wrong bit-type. Ignoring this JSON",
 icd_details[i].full_library_path);
 break;
 }
 case LOADER_LAYER_LIB_SUCCESS_LOADED:
 case LOADER_LAYER_LIB_ERROR_OUT_OF_MEMORY:
 // Shouldn't be able to reach this but if it is, best to report a debug
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "Shouldn't reach this. A valid version of requested ICD %s was loaded but something bad "
 "happened afterwards.",
 icd_details[i].full_library_path);
 break;
 }
 }
 }

out:
 if (NULL != icd_details) {
 // Successfully got the icd_details structure, which means we need to free the paths contained within
 for (uint32_t i = 0; i < manifest_files.count; i++) {
 loader_instance_heap_free(inst, icd_details[i].full_library_path);
 }
 }
 free_string_list(inst, &manifest_files);
 return res;
}

// Gets the layer data files corresponding to manifest_type & path_override, then parses the resulting json objects
// into instance_layers
// Manifest type must be either implicit or explicit
VkResult loader_parse_instance_layers(struct loader_instance *inst, enum loader_data_files_type manifest_type,
 const struct loader_string_list *path_overrides, struct loader_layer_list *instance_layers) {
 assert(manifest_type == LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER || manifest_type == LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER);
 VkResult res = VK_SUCCESS;
 struct loader_string_list manifest_files = {0};

 res = loader_get_data_files(inst, manifest_type, path_overrides, &manifest_files);
 if (VK_SUCCESS != res) {
 goto out;
 }

 for (uint32_t i = 0; i < manifest_files.count; i++) {
 char *file_str = manifest_files.list[i];
 if (file_str == NULL) {
 continue;
 }

 // Parse file into JSON struct
 cJSON *json = NULL;
 VkResult local_res = loader_get_json(inst, file_str, &json);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == local_res) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 } else if (VK_SUCCESS != local_res || NULL == json) {
 continue;
 }

 local_res = loader_add_layer_properties(inst, instance_layers, json,
 manifest_type == LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER, file_str);
 loader_cJSON_Delete(json);

 // If the error is anything other than out of memory we still want to try to load the other layers
 if (VK_ERROR_OUT_OF_HOST_MEMORY == local_res) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 }
out:
 free_string_list(inst, &manifest_files);

 return res;
}

// Given a loader_layer_properties struct that is a valid override layer, concatenate the properties override paths and put them
// into the output parameter override_paths
VkResult get_override_layer_override_paths(struct loader_instance *inst, struct loader_layer_properties *prop,
 struct loader_string_list *override_paths) {
 if (prop->override_paths.count > 0) {
 for (uint32_t j = 0; j < prop->override_paths.count; j++) {
 VkResult result = copy_data_file_info(inst, prop->override_paths.list[j], NULL, 0, override_paths);
 if (VK_SUCCESS != result) {
 return result;
 }
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Override layer has override path %s",
 prop->override_paths.list[j]);
 }
 }
 return VK_SUCCESS;
}

void loader_remove_duplicate_layers(struct loader_instance *inst, struct loader_layer_list *layers) {
 // Remove duplicate layers (that share the same layerName)
 for (uint32_t i = 0; i < layers->count; ++i) {
 bool has_duplicate = false;
 uint32_t duplicate_index = 0;
 for (uint32_t j = i + 1; j < layers->count; ++j) {
 if (strcmp(layers->list[i].info.layerName, layers->list[j].info.layerName) == 0) {
 has_duplicate = true;
 duplicate_index = j;
 break;
 }
 }
 if (has_duplicate) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0, "Removing layer %s (%s) because it is a duplicate of %s (%s)",
 layers->list[duplicate_index].info.layerName, layers->list[duplicate_index].manifest_file_name,
 layers->list[i].info.layerName, layers->list[i].manifest_file_name);
 loader_remove_layer_in_list(inst, layers, duplicate_index);
 }
 }
}

VkResult loader_scan_for_layers(struct loader_instance *inst, struct loader_layer_list *instance_layers,
 const struct loader_envvar_all_filters *filters) {
 VkResult res = VK_SUCCESS;
 struct loader_layer_list settings_layers = {0};
 struct loader_layer_list regular_instance_layers = {0};
 bool override_layer_valid = false;
 struct loader_string_list override_paths = {0};

 bool should_search_for_other_layers = true;
 res = get_settings_layers(inst, &settings_layers, &should_search_for_other_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // If we should not look for layers using other mechanisms, assign settings_layers to instance_layers and jump to the
 // output
 if (!should_search_for_other_layers) {
 *instance_layers = settings_layers;
 memset(&settings_layers, 0, sizeof(struct loader_layer_list));
 goto out;
 }

 res = loader_parse_instance_layers(inst, LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER, NULL, &regular_instance_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Remove any extraneous override layers.
 remove_all_non_valid_override_layers(inst, &regular_instance_layers);

 // Check to see if the override layer is present, and use it's override paths.
 for (uint32_t i = 0; i < regular_instance_layers.count; i++) {
 struct loader_layer_properties *prop = &regular_instance_layers.list[i];
 if (prop->is_override && loader_implicit_layer_is_enabled(inst, filters, prop) && prop->override_paths.count > 0) {
 res = get_override_layer_override_paths(inst, prop, &override_paths);
 if (VK_SUCCESS != res) {
 goto out;
 }
 break;
 }
 }

 // Get a list of manifest files for explicit layers
 res = loader_parse_instance_layers(inst, LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER, &override_paths, &regular_instance_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Verify any meta-layers in the list are valid and all the component layers are
 // actually present in the available layer list
 res = verify_all_meta_layers(inst, filters, &regular_instance_layers, &override_layer_valid);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 return res;
 }

 if (override_layer_valid) {
 loader_remove_layers_in_blacklist(inst, &regular_instance_layers);
 if (NULL != inst) {
 inst->override_layer_present = true;
 }
 }

 // Remove disabled layers
 for (uint32_t i = 0; i < regular_instance_layers.count; ++i) {
 if (!loader_layer_is_available(inst, filters, &regular_instance_layers.list[i])) {
 loader_remove_layer_in_list(inst, &regular_instance_layers, i);
 i--;
 }
 }

 // Make sure no layers have the same layerName
 loader_remove_duplicate_layers(inst, &regular_instance_layers);

 res = combine_settings_layers_with_regular_layers(inst, &settings_layers, &regular_instance_layers, instance_layers);

out:
 loader_delete_layer_list_and_properties(inst, &settings_layers);
 loader_delete_layer_list_and_properties(inst, &regular_instance_layers);

 free_string_list(inst, &override_paths);
 return res;
}

VkResult loader_scan_for_implicit_layers(struct loader_instance *inst, struct loader_layer_list *instance_layers,
 const struct loader_envvar_all_filters *layer_filters) {
 VkResult res = VK_SUCCESS;
 struct loader_layer_list settings_layers = {0};
 struct loader_layer_list regular_instance_layers = {0};
 bool override_layer_valid = false;
 struct loader_string_list override_paths = {0};
 bool implicit_metalayer_present = false;

 bool should_search_for_other_layers = true;
 res = get_settings_layers(inst, &settings_layers, &should_search_for_other_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Remove layers from settings file that are off, are explicit, or are implicit layers that aren't active
 for (uint32_t i = 0; i < settings_layers.count; ++i) {
 if (settings_layers.list[i].settings_control_value == LOADER_SETTINGS_LAYER_CONTROL_OFF ||
 settings_layers.list[i].settings_control_value == LOADER_SETTINGS_LAYER_UNORDERED_LAYER_LOCATION ||
 (settings_layers.list[i].type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER) == VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER ||
 !loader_implicit_layer_is_enabled(inst, layer_filters, &settings_layers.list[i])) {
 loader_remove_layer_in_list(inst, &settings_layers, i);
 i--;
 }
 }

 // If we should not look for layers using other mechanisms, assign settings_layers to instance_layers and jump to the
 // output
 if (!should_search_for_other_layers) {
 *instance_layers = settings_layers;
 memset(&settings_layers, 0, sizeof(struct loader_layer_list));
 goto out;
 }

 res = loader_parse_instance_layers(inst, LOADER_DATA_FILE_MANIFEST_IMPLICIT_LAYER, NULL, &regular_instance_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Remove any extraneous override layers.
 remove_all_non_valid_override_layers(inst, &regular_instance_layers);

 // Check to see if either the override layer is present, or another implicit meta-layer.
 // Each of these may require explicit layers to be enabled at this time.
 for (uint32_t i = 0; i < regular_instance_layers.count; i++) {
 struct loader_layer_properties *prop = &regular_instance_layers.list[i];
 if (prop->is_override && loader_implicit_layer_is_enabled(inst, layer_filters, prop)) {
 override_layer_valid = true;
 res = get_override_layer_override_paths(inst, prop, &override_paths);
 if (VK_SUCCESS != res) {
 goto out;
 }
 } else if (!prop->is_override && prop->type_flags & VK_LAYER_TYPE_FLAG_META_LAYER) {
 implicit_metalayer_present = true;
 }
 }

 // If either the override layer or an implicit meta-layer are present, we need to add
 // explicit layer info as well. Not to worry, though, all explicit layers not included
 // in the override layer will be removed below in loader_remove_layers_in_blacklist().
 if (override_layer_valid || implicit_metalayer_present) {
 res =
 loader_parse_instance_layers(inst, LOADER_DATA_FILE_MANIFEST_EXPLICIT_LAYER, &override_paths, &regular_instance_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 // Verify any meta-layers in the list are valid and all the component layers are
 // actually present in the available layer list
 res = verify_all_meta_layers(inst, layer_filters, &regular_instance_layers, &override_layer_valid);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 return res;
 }

 if (override_layer_valid || implicit_metalayer_present) {
 loader_remove_layers_not_in_implicit_meta_layers(inst, &regular_instance_layers);
 if (override_layer_valid && inst != NULL) {
 inst->override_layer_present = true;
 }
 }

 // Remove disabled layers
 for (uint32_t i = 0; i < regular_instance_layers.count; ++i) {
 if (!loader_implicit_layer_is_enabled(inst, layer_filters, &regular_instance_layers.list[i])) {
 loader_remove_layer_in_list(inst, &regular_instance_layers, i);
 i--;
 }
 }

 // Make sure no layers have the same layerName
 loader_remove_duplicate_layers(inst, &regular_instance_layers);

 res = combine_settings_layers_with_regular_layers(inst, &settings_layers, &regular_instance_layers, instance_layers);

out:
 loader_delete_layer_list_and_properties(inst, &settings_layers);
 loader_delete_layer_list_and_properties(inst, &regular_instance_layers);

 free_string_list(inst, &override_paths);
 return res;
}

VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL loader_gpdpa_instance_terminator(VkInstance inst, const char *pName) {
 // inst is not wrapped
 if (inst == VK_NULL_HANDLE) {
 return NULL;
 }

 VkLayerInstanceDispatchTable *disp_table = *(VkLayerInstanceDispatchTable **)inst;

 if (disp_table == NULL) return NULL;

 struct loader_instance *loader_inst = loader_get_instance(inst);

 if (loader_inst->instance_finished_creation) {
 disp_table = &loader_inst->terminator_dispatch;
 }

 bool found_name;
 void *addr = loader_lookup_instance_dispatch_table(disp_table, pName, &found_name);
 if (found_name) {
 return addr;
 }

 // Check if any drivers support the function, and if so, add it to the unknown function list
 addr = loader_phys_dev_ext_gpa_term(loader_get_instance(inst), pName);
 if (NULL != addr) return addr;

 // Don't call down the chain, this would be an infinite loop
 loader_log(NULL, VULKAN_LOADER_DEBUG_BIT, 0, "loader_gpdpa_instance_terminator() unrecognized name %s", pName);
 return NULL;
}

VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL loader_gpa_instance_terminator(VkInstance inst, const char *pName) {
 // Global functions - Do not need a valid instance handle to query
 if (!strcmp(pName, "vkGetInstanceProcAddr")) {
 return (PFN_vkVoidFunction)loader_gpa_instance_terminator;
 }
 if (!strcmp(pName, "vk_layerGetPhysicalDeviceProcAddr")) {
 return (PFN_vkVoidFunction)loader_gpdpa_instance_terminator;
 }
 if (!strcmp(pName, "vkCreateInstance")) {
 return (PFN_vkVoidFunction)terminator_CreateInstance;
 }
 // If a layer is querying pre-instance functions using vkGetInstanceProcAddr, we need to return function pointers that match the
 // Vulkan API
 if (!strcmp(pName, "vkEnumerateInstanceLayerProperties")) {
 return (PFN_vkVoidFunction)terminator_EnumerateInstanceLayerProperties;
 }
 if (!strcmp(pName, "vkEnumerateInstanceExtensionProperties")) {
 return (PFN_vkVoidFunction)terminator_EnumerateInstanceExtensionProperties;
 }
 if (!strcmp(pName, "vkEnumerateInstanceVersion")) {
 return (PFN_vkVoidFunction)terminator_EnumerateInstanceVersion;
 }

 // While the spec is very clear that querying vkCreateDevice requires a valid VkInstance, because the loader allowed querying
 // with a NULL VkInstance handle for a long enough time, it is impractical to fix this bug in the loader

 // As such, this is a bug to maintain compatibility for the RTSS layer (Riva Tuner Statistics Server) but may
 // be depended upon by other layers out in the wild.
 if (!strcmp(pName, "vkCreateDevice")) {
 return (PFN_vkVoidFunction)terminator_CreateDevice;
 }

 // inst is not wrapped
 if (inst == VK_NULL_HANDLE) {
 return NULL;
 }
 VkLayerInstanceDispatchTable *disp_table = *(VkLayerInstanceDispatchTable **)inst;

 if (disp_table == NULL) return NULL;

 struct loader_instance *loader_inst = loader_get_instance(inst);

 // The VK_EXT_debug_utils functions need a special case here so the terminators can still be found from
 // vkGetInstanceProcAddr This is because VK_EXT_debug_utils is an instance level extension with device level functions, and
 // is 'supported' by the loader.
 // These functions need a terminator to handle the case of a driver not supporting VK_EXT_debug_utils when there are layers
 // present which not check for NULL before calling the function.
 if (!strcmp(pName, "vkSetDebugUtilsObjectNameEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_SetDebugUtilsObjectNameEXT : NULL;
 }
 if (!strcmp(pName, "vkSetDebugUtilsObjectTagEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_SetDebugUtilsObjectTagEXT : NULL;
 }
 if (!strcmp(pName, "vkQueueBeginDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_QueueBeginDebugUtilsLabelEXT : NULL;
 }
 if (!strcmp(pName, "vkQueueEndDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_QueueEndDebugUtilsLabelEXT : NULL;
 }
 if (!strcmp(pName, "vkQueueInsertDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_QueueInsertDebugUtilsLabelEXT
 : NULL;
 }
 if (!strcmp(pName, "vkCmdBeginDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_CmdBeginDebugUtilsLabelEXT : NULL;
 }
 if (!strcmp(pName, "vkCmdEndDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_CmdEndDebugUtilsLabelEXT : NULL;
 }
 if (!strcmp(pName, "vkCmdInsertDebugUtilsLabelEXT")) {
 return loader_inst->enabled_extensions.ext_debug_utils ? (PFN_vkVoidFunction)terminator_CmdInsertDebugUtilsLabelEXT : NULL;
 }

 if (loader_inst->instance_finished_creation) {
 disp_table = &loader_inst->terminator_dispatch;
 }

 bool found_name;
 void *addr = loader_lookup_instance_dispatch_table(disp_table, pName, &found_name);
 if (found_name) {
 return addr;
 }

 // Check if it is an unknown physical device function, to see if any drivers support it.
 addr = loader_phys_dev_ext_gpa_term(loader_get_instance(inst), pName);
 if (addr) {
 return addr;
 }

 // Assume it is an unknown device function, check to see if any drivers support it.
 addr = loader_dev_ext_gpa_term(loader_get_instance(inst), pName);
 if (addr) {
 return addr;
 }

 // Don't call down the chain, this would be an infinite loop
 loader_log(NULL, VULKAN_LOADER_DEBUG_BIT, 0, "loader_gpa_instance_terminator() unrecognized name %s", pName);
 return NULL;
}

VKAPI_ATTR PFN_vkVoidFunction VKAPI_CALL loader_gpa_device_terminator(VkDevice device, const char *pName) {
 struct loader_device *dev;
 struct loader_icd_term *icd_term = loader_get_icd_and_device(device, &dev);

 // Return this function if a layer above here is asking for the vkGetDeviceProcAddr.
 // This is so we can properly intercept any device commands needing a terminator.
 if (!strcmp(pName, "vkGetDeviceProcAddr")) {
 return (PFN_vkVoidFunction)loader_gpa_device_terminator;
 }

 // NOTE: Device Funcs needing Trampoline/Terminator.
 // Overrides for device functions needing a trampoline and
 // a terminator because certain device entry-points still need to go
 // through a terminator before hitting the ICD. This could be for
 // several reasons, but the main one is currently unwrapping an
 // object before passing the appropriate info along to the ICD.
 // This is why we also have to override the direct ICD call to
 // vkGetDeviceProcAddr to intercept those calls.
 // If the pName is for a 'known' function but isn't available, due to
 // the corresponding extension/feature not being enabled, we need to
 // return NULL and not call down to the driver's GetDeviceProcAddr.
 if (NULL != dev) {
 bool found_name = false;
 PFN_vkVoidFunction addr = get_extension_device_proc_terminator(dev, pName, &found_name);
 if (found_name) {
 return addr;
 }
 }

 if (icd_term == NULL) {
 return NULL;
 }

 return icd_term->dispatch.GetDeviceProcAddr(device, pName);
}

struct loader_instance *loader_get_instance(const VkInstance instance) {
 // look up the loader_instance in our list by comparing dispatch tables, as
 // there is no guarantee the instance is still a loader_instance* after any
 // layers which wrap the instance object.
 const VkLayerInstanceDispatchTable *disp;
 struct loader_instance *ptr_instance = (struct loader_instance *)instance;
 if (VK_NULL_HANDLE == instance || LOADER_MAGIC_NUMBER != ptr_instance->magic) {
 return NULL;
 } else {
 disp = loader_get_instance_layer_dispatch(instance);
 loader_platform_thread_lock_mutex(&loader_lock);
 for (struct loader_instance *inst = loader.instances; inst; inst = inst->next) {
 if (&inst->disp->layer_inst_disp == disp) {
 ptr_instance = inst;
 break;
 }
 }
 loader_platform_thread_unlock_mutex(&loader_lock);
 }
 return ptr_instance;
}

loader_platform_dl_handle loader_open_layer_file(const struct loader_instance *inst, struct loader_layer_properties *prop) {
 if ((prop->lib_handle = loader_platform_open_library(prop->lib_name)) == NULL) {
 loader_handle_load_library_error(inst, prop->lib_name, &prop->lib_status);
 } else {
 prop->lib_status = LOADER_LAYER_LIB_SUCCESS_LOADED;
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Loading layer library %s", prop->lib_name);
 }

 return prop->lib_handle;
}

// Go through the search_list and find any layers which match type. If layer
// type match is found in then add it to ext_list.
// If the layer name is in enabled_layers_env, do not add it to the list, that way it can be ordered alongside the other env-var
// enabled layers
VkResult loader_add_implicit_layers(const struct loader_instance *inst, const char *enabled_layers_env,
 const struct loader_envvar_all_filters *filters, struct loader_pointer_layer_list *target_list,
 struct loader_pointer_layer_list *expanded_target_list,
 const struct loader_layer_list *source_list) {
 for (uint32_t src_layer = 0; src_layer < source_list->count; src_layer++) {
 struct loader_layer_properties *prop = &source_list->list[src_layer];
 if (0 == (prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER)) {
 // If this layer appears in the enabled_layers_env, don't add it. We will let loader_add_environment_layers handle it
 if (NULL == enabled_layers_env || NULL == strstr(enabled_layers_env, prop->info.layerName)) {
 VkResult result = loader_add_implicit_layer(inst, prop, filters, target_list, expanded_target_list, source_list);
 if (result == VK_ERROR_OUT_OF_HOST_MEMORY) return result;
 }
 }
 }
 return VK_SUCCESS;
}

void warn_if_layers_are_older_than_application(struct loader_instance *inst) {
 for (uint32_t i = 0; i < inst->expanded_activated_layer_list.count; i++) {
 // Verify that the layer api version is at least that of the application's request, if not, throw a warning since
 // undefined behavior could occur.
 struct loader_layer_properties *prop = inst->expanded_activated_layer_list.list[i];
 loader_api_version prop_spec_version = loader_make_version(prop->info.specVersion);
 if (!loader_check_version_meets_required(inst->app_api_version, prop_spec_version)) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Layer %s uses API version %u.%u which is older than the application specified "
 "API version of %u.%u. May cause issues.",
 prop->info.layerName, prop_spec_version.major, prop_spec_version.minor, inst->app_api_version.major,
 inst->app_api_version.minor);
 }
 }
}

VkResult loader_enable_instance_layers(struct loader_instance *inst, const VkInstanceCreateInfo *pCreateInfo,
 const struct loader_layer_list *instance_layers,
 const struct loader_envvar_all_filters *layer_filters) {
 VkResult res = VK_SUCCESS;
 char *enabled_layers_env = NULL;

 assert(inst && "Cannot have null instance");

 if (!loader_init_pointer_layer_list(inst, &inst->app_activated_layer_list)) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_enable_instance_layers: Failed to initialize application version of the layer list");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 if (!loader_init_pointer_layer_list(inst, &inst->expanded_activated_layer_list)) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_enable_instance_layers: Failed to initialize expanded version of the layer list");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 if (inst->settings.settings_active && inst->settings.layer_configurations_active) {
 res = enable_correct_layers_from_settings(inst, layer_filters, pCreateInfo->enabledLayerCount,
 pCreateInfo->ppEnabledLayerNames, &inst->instance_layer_list,
 &inst->app_activated_layer_list, &inst->expanded_activated_layer_list);
 warn_if_layers_are_older_than_application(inst);

 goto out;
 }

 enabled_layers_env = loader_getenv(ENABLED_LAYERS_ENV, inst);

 // Add any implicit layers first
 res = loader_add_implicit_layers(inst, enabled_layers_env, layer_filters, &inst->app_activated_layer_list,
 &inst->expanded_activated_layer_list, instance_layers);
 if (res != VK_SUCCESS) {
 goto out;
 }

 // Add any layers specified via environment variable next
 res = loader_add_environment_layers(inst, enabled_layers_env, layer_filters, &inst->app_activated_layer_list,
 &inst->expanded_activated_layer_list, instance_layers);
 if (res != VK_SUCCESS) {
 goto out;
 }

 // Add layers specified by the application
 res = loader_add_layer_names_to_list(inst, layer_filters, &inst->app_activated_layer_list, &inst->expanded_activated_layer_list,
 pCreateInfo->enabledLayerCount, pCreateInfo->ppEnabledLayerNames, instance_layers);

 warn_if_layers_are_older_than_application(inst);
out:
 if (enabled_layers_env != NULL) {
 loader_free_getenv(enabled_layers_env, inst);
 }

 return res;
}

// Determine the layer interface version to use.
bool loader_get_layer_interface_version(PFN_vkNegotiateLoaderLayerInterfaceVersion fp_negotiate_layer_version,
 VkNegotiateLayerInterface *interface_struct) {
 memset(interface_struct, 0, sizeof(VkNegotiateLayerInterface));
 interface_struct->sType = LAYER_NEGOTIATE_INTERFACE_STRUCT;
 interface_struct->loaderLayerInterfaceVersion = 1;
 interface_struct->pNext = NULL;

 if (fp_negotiate_layer_version != NULL) {
 // Layer supports the negotiation API, so call it with the loader's
 // latest version supported
 interface_struct->loaderLayerInterfaceVersion = CURRENT_LOADER_LAYER_INTERFACE_VERSION;
 VkResult result = fp_negotiate_layer_version(interface_struct);

 if (result != VK_SUCCESS) {
 // Layer no longer supports the loader's latest interface version so
 // fail loading the Layer
 return false;
 }
 }

 if (interface_struct->loaderLayerInterfaceVersion < MIN_SUPPORTED_LOADER_LAYER_INTERFACE_VERSION) {
 // Loader no longer supports the layer's latest interface version so
 // fail loading the layer
 return false;
 }

 return true;
}

// Every extension that has a loader-defined trampoline needs to be marked as enabled or disabled so that we know whether or
// not to return that trampoline when vkGetDeviceProcAddr is called
void setup_logical_device_enabled_layer_extensions(const struct loader_instance *inst, struct loader_device *dev,
 const struct loader_extension_list *icd_exts,
 const VkDeviceCreateInfo *pCreateInfo) {
 // no enabled extensions, early exit
 if (pCreateInfo->ppEnabledExtensionNames == NULL) {
 return;
 }
 // Can only setup debug marker as debug utils is an instance extensions.
 for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; ++i) {
 if (pCreateInfo->ppEnabledExtensionNames[i] &&
 !strcmp(pCreateInfo->ppEnabledExtensionNames[i], VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
 // Check if its supported by the driver
 for (uint32_t j = 0; j < icd_exts->count; ++j) {
 if (!strcmp(icd_exts->list[j].extensionName, VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
 dev->layer_extensions.ext_debug_marker_enabled = true;
 }
 }
 // also check if any layers support it.
 for (uint32_t j = 0; j < inst->app_activated_layer_list.count; j++) {
 struct loader_layer_properties *layer = inst->app_activated_layer_list.list[j];
 for (uint32_t k = 0; k < layer->device_extension_list.count; k++) {
 if (!strcmp(layer->device_extension_list.list[k].props.extensionName, VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
 dev->layer_extensions.ext_debug_marker_enabled = true;
 }
 }
 }
 }
 }
}

VKAPI_ATTR VkResult VKAPI_CALL loader_layer_create_device(VkInstance instance, VkPhysicalDevice physicalDevice,
 const VkDeviceCreateInfo *pCreateInfo,
 const VkAllocationCallbacks *pAllocator, VkDevice *pDevice,
 PFN_vkGetInstanceProcAddr layerGIPA, PFN_vkGetDeviceProcAddr *nextGDPA) {
 VkResult res;
 VkPhysicalDevice internal_device = VK_NULL_HANDLE;
 struct loader_device *dev = NULL;
 struct loader_instance *inst = NULL;

 if (instance != VK_NULL_HANDLE) {
 inst = loader_get_instance(instance);
 internal_device = physicalDevice;
 } else {
 struct loader_physical_device_tramp *phys_dev = (struct loader_physical_device_tramp *)physicalDevice;
 internal_device = phys_dev->phys_dev;
 inst = (struct loader_instance *)phys_dev->this_instance;
 }

 // Get the physical device (ICD) extensions
 struct loader_extension_list icd_exts = {0};
 icd_exts.list = NULL;
 res = loader_init_generic_list(inst, (struct loader_generic_list *)&icd_exts, sizeof(VkExtensionProperties));
 if (VK_SUCCESS != res) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "vkCreateDevice: Failed to create ICD extension list");
 goto out;
 }

 PFN_vkEnumerateDeviceExtensionProperties enumDeviceExtensionProperties = NULL;
 if (layerGIPA != NULL) {
 enumDeviceExtensionProperties =
 (PFN_vkEnumerateDeviceExtensionProperties)layerGIPA(instance, "vkEnumerateDeviceExtensionProperties");
 } else {
 enumDeviceExtensionProperties = inst->disp->layer_inst_disp.EnumerateDeviceExtensionProperties;
 }
 res = loader_add_device_extensions(inst, enumDeviceExtensionProperties, internal_device, "Unknown", &icd_exts);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "vkCreateDevice: Failed to add extensions to list");
 goto out;
 }

 // Make sure requested extensions to be enabled are supported
 res = loader_validate_device_extensions(inst, &inst->expanded_activated_layer_list, &icd_exts, pCreateInfo);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "vkCreateDevice: Failed to validate extensions in list");
 goto out;
 }

 dev = loader_create_logical_device(inst, pAllocator);
 if (dev == NULL) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 setup_logical_device_enabled_layer_extensions(inst, dev, &icd_exts, pCreateInfo);

 res = loader_create_device_chain(internal_device, pCreateInfo, pAllocator, inst, dev, layerGIPA, nextGDPA);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "vkCreateDevice: Failed to create device chain.");
 goto out;
 }

 *pDevice = dev->chain_device;

 // Initialize any device extension dispatch entry's from the instance list
 loader_init_dispatch_dev_ext(inst, dev);

 // Initialize WSI device extensions as part of core dispatch since loader
 // has dedicated trampoline code for these
 loader_init_device_extension_dispatch_table(&dev->loader_dispatch, inst->disp->layer_inst_disp.GetInstanceProcAddr,
 dev->loader_dispatch.core_dispatch.GetDeviceProcAddr, inst->instance, *pDevice);

out:

 // Failure cleanup
 if (VK_SUCCESS != res) {
 if (NULL != dev) {
 // Find the icd_term this device belongs to then remove it from that icd_term.
 // Need to iterate the linked lists and remove the device from it. Don't delete
 // the device here since it may not have been added to the icd_term and there
 // are other allocations attached to it.
 struct loader_icd_term *icd_term = inst->icd_terms;
 bool found = false;
 while (!found && NULL != icd_term) {
 struct loader_device *cur_dev = icd_term->logical_device_list;
 struct loader_device *prev_dev = NULL;
 while (NULL != cur_dev) {
 if (cur_dev == dev) {
 if (cur_dev == icd_term->logical_device_list) {
 icd_term->logical_device_list = cur_dev->next;
 } else if (prev_dev) {
 prev_dev->next = cur_dev->next;
 }

 found = true;
 break;
 }
 prev_dev = cur_dev;
 cur_dev = cur_dev->next;
 }
 icd_term = icd_term->next;
 }
 // Now destroy the device and the allocations associated with it.
 loader_destroy_logical_device(dev, pAllocator);
 }
 }

 if (NULL != icd_exts.list) {
 loader_destroy_generic_list(inst, (struct loader_generic_list *)&icd_exts);
 }
 return res;
}

VKAPI_ATTR void VKAPI_CALL loader_layer_destroy_device(VkDevice device, const VkAllocationCallbacks *pAllocator,
 PFN_vkDestroyDevice destroyFunction) {
 struct loader_device *dev;

 if (device == VK_NULL_HANDLE) {
 return;
 }

 struct loader_icd_term *icd_term = loader_get_icd_and_device(device, &dev);

 destroyFunction(device, pAllocator);
 if (NULL != dev) {
 dev->chain_device = NULL;
 dev->icd_device = NULL;
 loader_remove_logical_device(icd_term, dev, pAllocator);
 }
}

// Given the list of layers to activate in the loader_instance
// structure. This function will add a VkLayerInstanceCreateInfo
// structure to the VkInstanceCreateInfo.pNext pointer.
// Each activated layer will have it's own VkLayerInstanceLink
// structure that tells the layer what Get*ProcAddr to call to
// get function pointers to the next layer down.
// Once the chain info has been created this function will
// execute the CreateInstance call chain. Each layer will
// then have an opportunity in it's CreateInstance function
// to setup it's dispatch table when the lower layer returns
// successfully.
// Each layer can wrap or not-wrap the returned VkInstance object
// as it sees fit.
// The instance chain is terminated by a loader function
// that will call CreateInstance on all available ICD's and
// cache those VkInstance objects for future use.
VkResult loader_create_instance_chain(const VkInstanceCreateInfo *pCreateInfo, const VkAllocationCallbacks *pAllocator,
 struct loader_instance *inst, VkInstance *created_instance) {
 uint32_t num_activated_layers = 0;
 struct activated_layer_info *activated_layers = NULL;
 VkLayerInstanceCreateInfo chain_info;
 VkLayerInstanceLink *layer_instance_link_info = NULL;
 VkInstanceCreateInfo loader_create_info;
 VkResult res;

 PFN_vkGetInstanceProcAddr next_gipa = loader_gpa_instance_terminator;
 PFN_vkGetInstanceProcAddr cur_gipa = loader_gpa_instance_terminator;
 PFN_vkGetDeviceProcAddr cur_gdpa = loader_gpa_device_terminator;
 PFN_GetPhysicalDeviceProcAddr next_gpdpa = loader_gpdpa_instance_terminator;
 PFN_GetPhysicalDeviceProcAddr cur_gpdpa = loader_gpdpa_instance_terminator;

 memcpy(&loader_create_info, pCreateInfo, sizeof(VkInstanceCreateInfo));

 if (inst->expanded_activated_layer_list.count > 0) {
 chain_info.u.pLayerInfo = NULL;
 chain_info.pNext = pCreateInfo->pNext;
 chain_info.sType = VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO;
 chain_info.function = VK_LAYER_LINK_INFO;
 loader_create_info.pNext = &chain_info;

 layer_instance_link_info = loader_stack_alloc(sizeof(VkLayerInstanceLink) * inst->expanded_activated_layer_list.count);
 if (!layer_instance_link_info) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_create_instance_chain: Failed to alloc Instance objects for layer");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 activated_layers = loader_stack_alloc(sizeof(struct activated_layer_info) * inst->expanded_activated_layer_list.count);
 if (!activated_layers) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_create_instance_chain: Failed to alloc activated layer storage array");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 // Create instance chain of enabled layers
 for (int32_t i = inst->expanded_activated_layer_list.count - 1; i >= 0; i--) {
 struct loader_layer_properties *layer_prop = inst->expanded_activated_layer_list.list[i];
 loader_platform_dl_handle lib_handle;

 // Skip it if a Layer with the same name has been already successfully activated
 if (loader_names_array_has_layer_property(&layer_prop->info, num_activated_layers, activated_layers)) {
 continue;
 }

 lib_handle = loader_open_layer_file(inst, layer_prop);
 if (layer_prop->lib_status == LOADER_LAYER_LIB_ERROR_OUT_OF_MEMORY) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 if (!lib_handle) {
 continue;
 }

 if (NULL == layer_prop->functions.negotiate_layer_interface) {
 PFN_vkNegotiateLoaderLayerInterfaceVersion negotiate_interface = NULL;
 bool functions_in_interface = false;
 if (!layer_prop->functions.str_negotiate_interface || strlen(layer_prop->functions.str_negotiate_interface) == 0) {
 negotiate_interface = (PFN_vkNegotiateLoaderLayerInterfaceVersion)loader_platform_get_proc_address(
 lib_handle, "vkNegotiateLoaderLayerInterfaceVersion");
 } else {
 negotiate_interface = (PFN_vkNegotiateLoaderLayerInterfaceVersion)loader_platform_get_proc_address(
 lib_handle, layer_prop->functions.str_negotiate_interface);
 }

 // If we can negotiate an interface version, then we can also
 // get everything we need from the one function call, so try
 // that first, and see if we can get all the function pointers
 // necessary from that one call.
 if (NULL != negotiate_interface) {
 layer_prop->functions.negotiate_layer_interface = negotiate_interface;

 VkNegotiateLayerInterface interface_struct;

 if (loader_get_layer_interface_version(negotiate_interface, &interface_struct)) {
 // Go ahead and set the properties version to the
 // correct value.
 layer_prop->interface_version = interface_struct.loaderLayerInterfaceVersion;

 // If the interface is 2 or newer, we have access to the
 // new GetPhysicalDeviceProcAddr function, so grab it,
 // and the other necessary functions, from the
 // structure.
 if (interface_struct.loaderLayerInterfaceVersion > 1) {
 cur_gipa = interface_struct.pfnGetInstanceProcAddr;
 cur_gdpa = interface_struct.pfnGetDeviceProcAddr;
 cur_gpdpa = interface_struct.pfnGetPhysicalDeviceProcAddr;
 if (cur_gipa != NULL) {
 // We've set the functions, so make sure we
 // don't do the unnecessary calls later.
 functions_in_interface = true;
 }
 }
 }
 }

 if (!functions_in_interface) {
 if ((cur_gipa = layer_prop->functions.get_instance_proc_addr) == NULL) {
 if (layer_prop->functions.str_gipa == NULL || strlen(layer_prop->functions.str_gipa) == 0) {
 cur_gipa =
 (PFN_vkGetInstanceProcAddr)loader_platform_get_proc_address(lib_handle, "vkGetInstanceProcAddr");
 layer_prop->functions.get_instance_proc_addr = cur_gipa;

 if (NULL == cur_gipa) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_create_instance_chain: Failed to find \'vkGetInstanceProcAddr\' in layer \"%s\"",
 layer_prop->lib_name);
 continue;
 }
 } else {
 cur_gipa = (PFN_vkGetInstanceProcAddr)loader_platform_get_proc_address(lib_handle,
 layer_prop->functions.str_gipa);

 if (NULL == cur_gipa) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_create_instance_chain: Failed to find \'%s\' in layer \"%s\"",
 layer_prop->functions.str_gipa, layer_prop->lib_name);
 continue;
 }
 }
 }
 }
 }

 layer_instance_link_info[num_activated_layers].pNext = chain_info.u.pLayerInfo;
 layer_instance_link_info[num_activated_layers].pfnNextGetInstanceProcAddr = next_gipa;
 layer_instance_link_info[num_activated_layers].pfnNextGetPhysicalDeviceProcAddr = next_gpdpa;
 next_gipa = cur_gipa;
 if (layer_prop->interface_version > 1 && cur_gpdpa != NULL) {
 layer_prop->functions.get_physical_device_proc_addr = cur_gpdpa;
 next_gpdpa = cur_gpdpa;
 }
 if (layer_prop->interface_version > 1 && cur_gipa != NULL) {
 layer_prop->functions.get_instance_proc_addr = cur_gipa;
 }
 if (layer_prop->interface_version > 1 && cur_gdpa != NULL) {
 layer_prop->functions.get_device_proc_addr = cur_gdpa;
 }

 chain_info.u.pLayerInfo = &layer_instance_link_info[num_activated_layers];

 res = fixup_library_binary_path(inst, &(layer_prop->lib_name), layer_prop->lib_handle, cur_gipa);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }

 activated_layers[num_activated_layers].name = layer_prop->info.layerName;
 activated_layers[num_activated_layers].manifest = layer_prop->manifest_file_name;
 activated_layers[num_activated_layers].library = layer_prop->lib_name;
 activated_layers[num_activated_layers].is_implicit = !(layer_prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER);
 activated_layers[num_activated_layers].enabled_by_what = layer_prop->enabled_by_what;
 if (activated_layers[num_activated_layers].is_implicit) {
 activated_layers[num_activated_layers].disable_env = layer_prop->disable_env_var.name;
 activated_layers[num_activated_layers].enable_name_env = layer_prop->enable_env_var.name;
 activated_layers[num_activated_layers].enable_value_env = layer_prop->enable_env_var.value;
 }

 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Insert instance layer \"%s\" (%s)",
 layer_prop->info.layerName, layer_prop->lib_name);

 num_activated_layers++;
 }
 }

 // Make sure each layer requested by the application was actually loaded
 for (uint32_t exp = 0; exp < inst->expanded_activated_layer_list.count; ++exp) {
 struct loader_layer_properties *exp_layer_prop = inst->expanded_activated_layer_list.list[exp];
 bool found = false;
 for (uint32_t act = 0; act < num_activated_layers; ++act) {
 if (!strcmp(activated_layers[act].name, exp_layer_prop->info.layerName)) {
 found = true;
 break;
 }
 }
 // If it wasn't found, we want to at least log an error. However, if it was enabled by the application directly,
 // we want to return a bad layer error.
 if (!found) {
 bool app_requested = false;
 for (uint32_t act = 0; act < pCreateInfo->enabledLayerCount; ++act) {
 if (!strcmp(pCreateInfo->ppEnabledLayerNames[act], exp_layer_prop->info.layerName)) {
 app_requested = true;
 break;
 }
 }
 VkFlags log_flag = VULKAN_LOADER_LAYER_BIT;
 char ending = '.';
 if (app_requested) {
 log_flag |= VULKAN_LOADER_ERROR_BIT;
 ending = '!';
 } else {
 log_flag |= VULKAN_LOADER_INFO_BIT;
 }
 switch (exp_layer_prop->lib_status) {
 case LOADER_LAYER_LIB_NOT_LOADED:
 loader_log(inst, log_flag, 0, "Requested layer \"%s\" was not loaded%c", exp_layer_prop->info.layerName,
 ending);
 break;
 case LOADER_LAYER_LIB_ERROR_WRONG_BIT_TYPE: {
 loader_log(inst, log_flag, 0, "Requested layer \"%s\" was wrong bit-type%c", exp_layer_prop->info.layerName,
 ending);
 break;
 }
 case LOADER_LAYER_LIB_ERROR_FAILED_TO_LOAD:
 loader_log(inst, log_flag, 0, "Requested layer \"%s\" failed to load%c", exp_layer_prop->info.layerName,
 ending);
 break;
 case LOADER_LAYER_LIB_SUCCESS_LOADED:
 case LOADER_LAYER_LIB_ERROR_OUT_OF_MEMORY:
 // Shouldn't be able to reach this but if it is, best to report a debug
 loader_log(inst, log_flag, 0,
 "Shouldn't reach this. A valid version of requested layer %s was loaded but was not found in the "
 "list of activated layers%c",
 exp_layer_prop->info.layerName, ending);
 break;
 }
 if (app_requested) {
 return VK_ERROR_LAYER_NOT_PRESENT;
 }
 }
 }

 VkLoaderFeatureFlags feature_flags = 0;
#if defined(_WIN32)
 feature_flags = windows_initialize_dxgi();
#endif

 // The following line of code is actually invalid at least according to the Vulkan spec with header update 1.2.193 and onwards.
 // The update required calls to vkGetInstanceProcAddr querying "global" functions (which includes vkCreateInstance) to pass NULL
 // for the instance parameter. Because it wasn't required to be NULL before, there may be layers which expect the loader's
 // behavior of passing a non-NULL value into vkGetInstanceProcAddr.
 // In an abundance of caution, the incorrect code remains as is, with a big comment to indicate that its wrong
 PFN_vkCreateInstance fpCreateInstance = (PFN_vkCreateInstance)next_gipa(*created_instance, "vkCreateInstance");
 if (fpCreateInstance) {
 VkLayerInstanceCreateInfo instance_dispatch;
 instance_dispatch.sType = VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO;
 instance_dispatch.pNext = loader_create_info.pNext;
 instance_dispatch.function = VK_LOADER_DATA_CALLBACK;
 instance_dispatch.u.pfnSetInstanceLoaderData = vkSetInstanceDispatch;

 VkLayerInstanceCreateInfo device_callback;
 device_callback.sType = VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO;
 device_callback.pNext = &instance_dispatch;
 device_callback.function = VK_LOADER_LAYER_CREATE_DEVICE_CALLBACK;
 device_callback.u.layerDevice.pfnLayerCreateDevice = loader_layer_create_device;
 device_callback.u.layerDevice.pfnLayerDestroyDevice = loader_layer_destroy_device;

 VkLayerInstanceCreateInfo loader_features;
 loader_features.sType = VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO;
 loader_features.pNext = &device_callback;
 loader_features.function = VK_LOADER_FEATURES;
 loader_features.u.loaderFeatures = feature_flags;

 loader_create_info.pNext = &loader_features;

 // If layer debugging is enabled, let's print out the full callstack with layers in their
 // defined order.
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, "vkCreateInstance layer callstack setup to:");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " <Application>");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " ||");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " <Loader>");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " ||");
 for (uint32_t cur_layer = 0; cur_layer < num_activated_layers; ++cur_layer) {
 uint32_t index = num_activated_layers - cur_layer - 1;
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " %s", activated_layers[index].name);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Type: %s",
 activated_layers[index].is_implicit ? "Implicit" : "Explicit");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Enabled By: %s",
 get_enabled_by_what_str(activated_layers[index].enabled_by_what));
 if (activated_layers[index].is_implicit) {
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Disable Env Var: %s",
 activated_layers[index].disable_env);
 if (activated_layers[index].enable_name_env) {
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0,
 " This layer was enabled because Env Var %s was set to Value %s",
 activated_layers[index].enable_name_env, activated_layers[index].enable_value_env);
 }
 }
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Manifest: %s", activated_layers[index].manifest);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Library: %s", activated_layers[index].library);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " ||");
 }
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " <Drivers>");

 res = fpCreateInstance(&loader_create_info, pAllocator, created_instance);
 } else {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0, "loader_create_instance_chain: Failed to find \'vkCreateInstance\'");
 // Couldn't find CreateInstance function!
 res = VK_ERROR_INITIALIZATION_FAILED;
 }

 if (res == VK_SUCCESS) {
 // Copy the current disp table into the terminator_dispatch table so we can use it in loader_gpa_instance_terminator()
 memcpy(&inst->terminator_dispatch, &inst->disp->layer_inst_disp, sizeof(VkLayerInstanceDispatchTable));

 loader_init_instance_core_dispatch_table(&inst->disp->layer_inst_disp, next_gipa, *created_instance);
 inst->instance = *created_instance;

 if (pCreateInfo->enabledLayerCount > 0 && pCreateInfo->ppEnabledLayerNames != NULL) {
 res = create_string_list(inst, pCreateInfo->enabledLayerCount, &inst->enabled_layer_names);
 if (res != VK_SUCCESS) {
 return res;
 }

 for (uint32_t i = 0; i < pCreateInfo->enabledLayerCount; ++i) {
 res = copy_str_to_string_list(inst, &inst->enabled_layer_names, pCreateInfo->ppEnabledLayerNames[i],
 strlen(pCreateInfo->ppEnabledLayerNames[i]));
 if (res != VK_SUCCESS) return res;
 }
 }
 }

 return res;
}

void loader_activate_instance_layer_extensions(struct loader_instance *inst, VkInstance created_inst) {
 loader_init_instance_extension_dispatch_table(&inst->disp->layer_inst_disp, inst->disp->layer_inst_disp.GetInstanceProcAddr,
 created_inst);
}

#if defined(__APPLE__)
VkResult loader_create_device_chain(const VkPhysicalDevice pd, const VkDeviceCreateInfo *pCreateInfo,
 const VkAllocationCallbacks *pAllocator, const struct loader_instance *inst,
 struct loader_device *dev, PFN_vkGetInstanceProcAddr callingLayer,
 PFN_vkGetDeviceProcAddr *layerNextGDPA) __attribute__((optnone)) {
#else
VkResult loader_create_device_chain(const VkPhysicalDevice pd, const VkDeviceCreateInfo *pCreateInfo,
 const VkAllocationCallbacks *pAllocator, const struct loader_instance *inst,
 struct loader_device *dev, PFN_vkGetInstanceProcAddr callingLayer,
 PFN_vkGetDeviceProcAddr *layerNextGDPA) {
#endif
 uint32_t num_activated_layers = 0;
 struct activated_layer_info *activated_layers = NULL;
 VkLayerDeviceLink *layer_device_link_info;
 VkLayerDeviceCreateInfo chain_info;
 VkDeviceCreateInfo loader_create_info;
 VkDeviceGroupDeviceCreateInfo *original_device_group_create_info_struct = NULL;
 VkResult res;

 PFN_vkGetDeviceProcAddr fpGDPA = NULL, nextGDPA = loader_gpa_device_terminator;
 PFN_vkGetInstanceProcAddr fpGIPA = NULL, nextGIPA = loader_gpa_instance_terminator;

 memcpy(&loader_create_info, pCreateInfo, sizeof(VkDeviceCreateInfo));

 if (loader_create_info.enabledLayerCount > 0 && loader_create_info.ppEnabledLayerNames != NULL) {
 bool invalid_device_layer_usage = false;

 if (loader_create_info.enabledLayerCount != inst->enabled_layer_names.count && loader_create_info.enabledLayerCount > 0) {
 invalid_device_layer_usage = true;
 } else if (loader_create_info.enabledLayerCount > 0 && loader_create_info.ppEnabledLayerNames == NULL) {
 invalid_device_layer_usage = true;
 } else if (loader_create_info.enabledLayerCount == 0 && loader_create_info.ppEnabledLayerNames != NULL) {
 invalid_device_layer_usage = true;
 } else if (inst->enabled_layer_names.list != NULL) {
 for (uint32_t i = 0; i < loader_create_info.enabledLayerCount; i++) {
 const char *device_layer_names = loader_create_info.ppEnabledLayerNames[i];

 if (strcmp(device_layer_names, inst->enabled_layer_names.list[i]) != 0) {
 invalid_device_layer_usage = true;
 break;
 }
 }
 }

 if (invalid_device_layer_usage) {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_create_device_chain: Using deprecated and ignored 'ppEnabledLayerNames' member of 'VkDeviceCreateInfo' "
 "when creating a Vulkan device.");
 }
 }

 // Before we continue, we need to find out if the KHR_device_group extension is in the enabled list. If it is, we then
 // need to look for the corresponding VkDeviceGroupDeviceCreateInfo struct in the device list. This is because we
 // need to replace all the incoming physical device values (which are really loader trampoline physical device values)
 // with the layer/ICD version.
 {
 VkBaseOutStructure *pNext = (VkBaseOutStructure *)loader_create_info.pNext;
 VkBaseOutStructure *pPrev = (VkBaseOutStructure *)&loader_create_info;
 while (NULL != pNext) {
 if (VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO == pNext->sType) {
 VkDeviceGroupDeviceCreateInfo *cur_struct = (VkDeviceGroupDeviceCreateInfo *)pNext;
 if (0 < cur_struct->physicalDeviceCount && NULL != cur_struct->pPhysicalDevices) {
 VkDeviceGroupDeviceCreateInfo *temp_struct = loader_stack_alloc(sizeof(VkDeviceGroupDeviceCreateInfo));
 VkPhysicalDevice *phys_dev_array = NULL;
 if (NULL == temp_struct) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 memcpy(temp_struct, cur_struct, sizeof(VkDeviceGroupDeviceCreateInfo));
 phys_dev_array = loader_stack_alloc(sizeof(VkPhysicalDevice) * cur_struct->physicalDeviceCount);
 if (NULL == phys_dev_array) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 // Before calling down, replace the incoming physical device values (which are really loader trampoline
 // physical devices) with the next layer (or possibly even the terminator) physical device values.
 struct loader_physical_device_tramp *cur_tramp;
 for (uint32_t phys_dev = 0; phys_dev < cur_struct->physicalDeviceCount; phys_dev++) {
 cur_tramp = (struct loader_physical_device_tramp *)cur_struct->pPhysicalDevices[phys_dev];
 phys_dev_array[phys_dev] = cur_tramp->phys_dev;
 }
 temp_struct->pPhysicalDevices = phys_dev_array;

 original_device_group_create_info_struct = (VkDeviceGroupDeviceCreateInfo *)pPrev->pNext;

 // Replace the old struct in the pNext chain with this one.
 pPrev->pNext = (VkBaseOutStructure *)temp_struct;
 }
 break;
 }

 pPrev = pNext;
 pNext = pNext->pNext;
 }
 }
 if (inst->expanded_activated_layer_list.count > 0) {
 layer_device_link_info = loader_stack_alloc(sizeof(VkLayerDeviceLink) * inst->expanded_activated_layer_list.count);
 if (!layer_device_link_info) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_create_device_chain: Failed to alloc Device objects for layer. Skipping Layer.");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 activated_layers = loader_stack_alloc(sizeof(struct activated_layer_info) * inst->expanded_activated_layer_list.count);
 if (!activated_layers) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_create_device_chain: Failed to alloc activated layer storage array");
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 chain_info.sType = VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO;
 chain_info.function = VK_LAYER_LINK_INFO;
 chain_info.u.pLayerInfo = NULL;
 chain_info.pNext = loader_create_info.pNext;
 loader_create_info.pNext = &chain_info;

 // Create instance chain of enabled layers
 for (int32_t i = inst->expanded_activated_layer_list.count - 1; i >= 0; i--) {
 struct loader_layer_properties *layer_prop = inst->expanded_activated_layer_list.list[i];
 loader_platform_dl_handle lib_handle = layer_prop->lib_handle;

 // Skip it if a Layer with the same name has been already successfully activated
 if (loader_names_array_has_layer_property(&layer_prop->info, num_activated_layers, activated_layers)) {
 continue;
 }

 // Skip the layer if the handle is NULL - this is likely because the library failed to load but wasn't removed from
 // the list.
 if (!lib_handle) {
 continue;
 }

 // The Get*ProcAddr pointers will already be filled in if they were received from either the json file or the
 // version negotiation
 if ((fpGIPA = layer_prop->functions.get_instance_proc_addr) == NULL) {
 if (layer_prop->functions.str_gipa == NULL || strlen(layer_prop->functions.str_gipa) == 0) {
 fpGIPA = (PFN_vkGetInstanceProcAddr)loader_platform_get_proc_address(lib_handle, "vkGetInstanceProcAddr");
 layer_prop->functions.get_instance_proc_addr = fpGIPA;
 } else
 fpGIPA =
 (PFN_vkGetInstanceProcAddr)loader_platform_get_proc_address(lib_handle, layer_prop->functions.str_gipa);
 if (!fpGIPA) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "loader_create_device_chain: Failed to find \'vkGetInstanceProcAddr\' in layer \"%s\". "
 "Skipping layer.",
 layer_prop->lib_name);
 continue;
 }
 }

 if (fpGIPA == callingLayer) {
 if (layerNextGDPA != NULL) {
 *layerNextGDPA = nextGDPA;
 }
 // Break here because if fpGIPA is the same as callingLayer, that means a layer is trying to create a device,
 // and once we don't want to continue any further as the next layer will be the calling layer
 break;
 }

 if ((fpGDPA = layer_prop->functions.get_device_proc_addr) == NULL) {
 if (layer_prop->functions.str_gdpa == NULL || strlen(layer_prop->functions.str_gdpa) == 0) {
 fpGDPA = (PFN_vkGetDeviceProcAddr)loader_platform_get_proc_address(lib_handle, "vkGetDeviceProcAddr");
 layer_prop->functions.get_device_proc_addr = fpGDPA;
 } else
 fpGDPA = (PFN_vkGetDeviceProcAddr)loader_platform_get_proc_address(lib_handle, layer_prop->functions.str_gdpa);
 if (!fpGDPA) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0,
 "Failed to find vkGetDeviceProcAddr in layer \"%s\"", layer_prop->lib_name);
 continue;
 }
 }

 layer_device_link_info[num_activated_layers].pNext = chain_info.u.pLayerInfo;
 layer_device_link_info[num_activated_layers].pfnNextGetInstanceProcAddr = nextGIPA;
 layer_device_link_info[num_activated_layers].pfnNextGetDeviceProcAddr = nextGDPA;
 chain_info.u.pLayerInfo = &layer_device_link_info[num_activated_layers];
 nextGIPA = fpGIPA;
 nextGDPA = fpGDPA;

 activated_layers[num_activated_layers].name = layer_prop->info.layerName;
 activated_layers[num_activated_layers].manifest = layer_prop->manifest_file_name;
 activated_layers[num_activated_layers].library = layer_prop->lib_name;
 activated_layers[num_activated_layers].is_implicit = !(layer_prop->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER);
 activated_layers[num_activated_layers].enabled_by_what = layer_prop->enabled_by_what;
 if (activated_layers[num_activated_layers].is_implicit) {
 activated_layers[num_activated_layers].disable_env = layer_prop->disable_env_var.name;
 }

 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_LAYER_BIT, 0, "Inserted device layer \"%s\" (%s)",
 layer_prop->info.layerName, layer_prop->lib_name);

 num_activated_layers++;
 }
 }

 VkDevice created_device = (VkDevice)dev;
 PFN_vkCreateDevice fpCreateDevice = (PFN_vkCreateDevice)nextGIPA(inst->instance, "vkCreateDevice");
 if (fpCreateDevice) {
 VkLayerDeviceCreateInfo create_info_disp;

 create_info_disp.sType = VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO;
 create_info_disp.function = VK_LOADER_DATA_CALLBACK;

 create_info_disp.u.pfnSetDeviceLoaderData = vkSetDeviceDispatch;

 // If layer debugging is enabled, let's print out the full callstack with layers in their
 // defined order.
 uint32_t layer_driver_bits = VULKAN_LOADER_LAYER_BIT | VULKAN_LOADER_DRIVER_BIT;
 loader_log(inst, layer_driver_bits, 0, "vkCreateDevice layer callstack setup to:");
 loader_log(inst, layer_driver_bits, 0, " <Application>");
 loader_log(inst, layer_driver_bits, 0, " ||");
 loader_log(inst, layer_driver_bits, 0, " <Loader>");
 loader_log(inst, layer_driver_bits, 0, " ||");
 for (uint32_t cur_layer = 0; cur_layer < num_activated_layers; ++cur_layer) {
 uint32_t index = num_activated_layers - cur_layer - 1;
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " %s", activated_layers[index].name);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Type: %s",
 activated_layers[index].is_implicit ? "Implicit" : "Explicit");
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Enabled By: %s",
 get_enabled_by_what_str(activated_layers[index].enabled_by_what));
 if (activated_layers[index].is_implicit) {
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Disable Env Var: %s",
 activated_layers[index].disable_env);
 }
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Manifest: %s", activated_layers[index].manifest);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " Library: %s", activated_layers[index].library);
 loader_log(inst, VULKAN_LOADER_LAYER_BIT, 0, " ||");
 }
 loader_log(inst, layer_driver_bits, 0, " <Device>");
 create_info_disp.pNext = loader_create_info.pNext;
 loader_create_info.pNext = &create_info_disp;
 res = fpCreateDevice(pd, &loader_create_info, pAllocator, &created_device);
 if (res != VK_SUCCESS) {
 return res;
 }
 dev->chain_device = created_device;

 // Because we changed the pNext chain to use our own VkDeviceGroupDeviceCreateInfo, we need to fixup the chain to
 // point back at the original VkDeviceGroupDeviceCreateInfo.
 VkBaseOutStructure *pNext = (VkBaseOutStructure *)loader_create_info.pNext;
 VkBaseOutStructure *pPrev = (VkBaseOutStructure *)&loader_create_info;
 while (NULL != pNext) {
 if (VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO == pNext->sType) {
 VkDeviceGroupDeviceCreateInfo *cur_struct = (VkDeviceGroupDeviceCreateInfo *)pNext;
 if (0 < cur_struct->physicalDeviceCount && NULL != cur_struct->pPhysicalDevices) {
 pPrev->pNext = (VkBaseOutStructure *)original_device_group_create_info_struct;
 }
 break;
 }

 pPrev = pNext;
 pNext = pNext->pNext;
 }

 } else {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_create_device_chain: Failed to find \'vkCreateDevice\' in layers or ICD");
 // Couldn't find CreateDevice function!
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 // Initialize device dispatch table
 loader_init_device_dispatch_table(&dev->loader_dispatch, nextGDPA, dev->chain_device);
 // Initialize the dispatch table to functions which need terminators
 // These functions point directly to the driver, not the terminator functions
 init_extension_device_proc_terminator_dispatch(dev);

 return res;
}

VkResult loader_validate_layers(const struct loader_instance *inst, const uint32_t layer_count,
 const char *const *ppEnabledLayerNames, const struct loader_layer_list *list) {
 struct loader_layer_properties *prop;

 if (layer_count > 0 && ppEnabledLayerNames == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_layers: ppEnabledLayerNames is NULL but enabledLayerCount is greater than zero");
 return VK_ERROR_LAYER_NOT_PRESENT;
 }

 for (uint32_t i = 0; i < layer_count; i++) {
 VkStringErrorFlags result = vk_string_validate(MaxLoaderStringLength, ppEnabledLayerNames[i]);
 if (result != VK_STRING_ERROR_NONE) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_layers: ppEnabledLayerNames contains string that is too long or is badly formed");
 return VK_ERROR_LAYER_NOT_PRESENT;
 }

 prop = loader_find_layer_property(ppEnabledLayerNames[i], list);
 if (NULL == prop) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_layers: Layer %d does not exist in the list of available layers", i);
 return VK_ERROR_LAYER_NOT_PRESENT;
 }
 if (inst->settings.settings_active && inst->settings.layer_configurations_active &&
 prop->settings_control_value != LOADER_SETTINGS_LAYER_CONTROL_ON &&
 prop->settings_control_value != LOADER_SETTINGS_LAYER_CONTROL_DEFAULT) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_layers: Layer %d was explicitly prevented from being enabled by the loader settings file",
 i);
 return VK_ERROR_LAYER_NOT_PRESENT;
 }
 }
 return VK_SUCCESS;
}

VkResult loader_validate_instance_extensions(struct loader_instance *inst, const struct loader_extension_list *icd_exts,
 const struct loader_layer_list *instance_layers,
 const struct loader_envvar_all_filters *layer_filters,
 const VkInstanceCreateInfo *pCreateInfo) {
 VkExtensionProperties *extension_prop;
 char *env_value;
 char *enabled_layers_env = NULL;
 bool check_if_known = true;
 VkResult res = VK_SUCCESS;

 struct loader_pointer_layer_list active_layers = {0};
 struct loader_pointer_layer_list expanded_layers = {0};

 if (pCreateInfo->enabledExtensionCount > 0 && pCreateInfo->ppEnabledExtensionNames == NULL) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_instance_extensions: Instance ppEnabledExtensionNames is NULL but enabledExtensionCount is "
 "greater than zero");
 return VK_ERROR_EXTENSION_NOT_PRESENT;
 }
 if (!loader_init_pointer_layer_list(inst, &active_layers)) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 if (!loader_init_pointer_layer_list(inst, &expanded_layers)) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 if (inst->settings.settings_active && inst->settings.layer_configurations_active) {
 res = enable_correct_layers_from_settings(inst, layer_filters, pCreateInfo->enabledLayerCount,
 pCreateInfo->ppEnabledLayerNames, instance_layers, &active_layers,
 &expanded_layers);
 if (res != VK_SUCCESS) {
 goto out;
 }
 } else {
 enabled_layers_env = loader_getenv(ENABLED_LAYERS_ENV, inst);

 // Build the lists of active layers (including meta layers) and expanded layers (with meta layers resolved to their
 // components)
 res =
 loader_add_implicit_layers(inst, enabled_layers_env, layer_filters, &active_layers, &expanded_layers, instance_layers);
 if (res != VK_SUCCESS) {
 goto out;
 }
 res = loader_add_environment_layers(inst, enabled_layers_env, layer_filters, &active_layers, &expanded_layers,
 instance_layers);
 if (res != VK_SUCCESS) {
 goto out;
 }
 res = loader_add_layer_names_to_list(inst, layer_filters, &active_layers, &expanded_layers, pCreateInfo->enabledLayerCount,
 pCreateInfo->ppEnabledLayerNames, instance_layers);
 if (VK_SUCCESS != res) {
 goto out;
 }
 }
 for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; i++) {
 VkStringErrorFlags result = vk_string_validate(MaxLoaderStringLength, pCreateInfo->ppEnabledExtensionNames[i]);
 if (result != VK_STRING_ERROR_NONE) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_instance_extensions: Instance ppEnabledExtensionNames contains "
 "string that is too long or is badly formed");
 res = VK_ERROR_EXTENSION_NOT_PRESENT;
 goto out;
 }

 // Check if a user wants to disable the instance extension filtering behavior
 env_value = loader_getenv("VK_LOADER_DISABLE_INST_EXT_FILTER", inst);
 if (NULL != env_value && atoi(env_value) != 0) {
 check_if_known = false;
 }
 loader_free_getenv(env_value, inst);

 if (check_if_known) {
 // See if the extension is in the list of supported extensions
 bool found = false;
 for (uint32_t j = 0; LOADER_INSTANCE_EXTENSIONS[j] != NULL; j++) {
 if (strcmp(pCreateInfo->ppEnabledExtensionNames[i], LOADER_INSTANCE_EXTENSIONS[j]) == 0) {
 found = true;
 break;
 }
 }

 // If it isn't in the list, return an error
 if (!found) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_instance_extensions: Extension %s not found in list of known instance extensions.",
 pCreateInfo->ppEnabledExtensionNames[i]);
 res = VK_ERROR_EXTENSION_NOT_PRESENT;
 goto out;
 }
 }

 extension_prop = get_extension_property(pCreateInfo->ppEnabledExtensionNames[i], icd_exts);

 if (extension_prop) {
 continue;
 }

 extension_prop = NULL;

 // Not in global list, search layer extension lists
 for (uint32_t j = 0; NULL == extension_prop && j < expanded_layers.count; ++j) {
 extension_prop =
 get_extension_property(pCreateInfo->ppEnabledExtensionNames[i], &expanded_layers.list[j]->instance_extension_list);
 if (extension_prop) {
 // Found the extension in one of the layers enabled by the app.
 break;
 }

 struct loader_layer_properties *layer_prop =
 loader_find_layer_property(expanded_layers.list[j]->info.layerName, instance_layers);
 if (NULL == layer_prop) {
 // Should NOT get here, loader_validate_layers should have already filtered this case out.
 continue;
 }
 }

 if (!extension_prop) {
 // Didn't find extension name in any of the global layers, error out
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_instance_extensions: Instance extension %s not supported by available ICDs or enabled "
 "layers.",
 pCreateInfo->ppEnabledExtensionNames[i]);
 res = VK_ERROR_EXTENSION_NOT_PRESENT;
 goto out;
 }
 }

out:
 loader_destroy_pointer_layer_list(inst, &active_layers);
 loader_destroy_pointer_layer_list(inst, &expanded_layers);
 if (enabled_layers_env != NULL) {
 loader_free_getenv(enabled_layers_env, inst);
 }

 return res;
}

VkResult loader_validate_device_extensions(struct loader_instance *this_instance,
 const struct loader_pointer_layer_list *activated_device_layers,
 const struct loader_extension_list *icd_exts, const VkDeviceCreateInfo *pCreateInfo) {
 // Early out to prevent nullptr dereference
 if (pCreateInfo->enabledExtensionCount == 0 || pCreateInfo->ppEnabledExtensionNames == NULL) {
 return VK_SUCCESS;
 }
 for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; i++) {
 if (pCreateInfo->ppEnabledExtensionNames[i] == NULL) {
 continue;
 }
 VkStringErrorFlags result = vk_string_validate(MaxLoaderStringLength, pCreateInfo->ppEnabledExtensionNames[i]);
 if (result != VK_STRING_ERROR_NONE) {
 loader_log(this_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_device_extensions: Device ppEnabledExtensionNames contains "
 "string that is too long or is badly formed");
 return VK_ERROR_EXTENSION_NOT_PRESENT;
 }

 const char *extension_name = pCreateInfo->ppEnabledExtensionNames[i];
 VkExtensionProperties *extension_prop = get_extension_property(extension_name, icd_exts);

 if (extension_prop) {
 continue;
 }

 // Not in global list, search activated layer extension lists
 for (uint32_t j = 0; j < activated_device_layers->count; j++) {
 struct loader_layer_properties *layer_prop = activated_device_layers->list[j];

 extension_prop = get_dev_extension_property(extension_name, &layer_prop->device_extension_list);
 if (extension_prop) {
 // Found the extension in one of the layers enabled by the app.
 break;
 }
 }

 if (!extension_prop) {
 // Didn't find extension name in any of the device layers, error out
 loader_log(this_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "loader_validate_device_extensions: Device extension %s not supported by selected physical device "
 "or enabled layers.",
 pCreateInfo->ppEnabledExtensionNames[i]);
 return VK_ERROR_EXTENSION_NOT_PRESENT;
 }
 }
 return VK_SUCCESS;
}

// Terminator functions for the Instance chain
// All named terminator_<Vulkan API name>
VKAPI_ATTR VkResult VKAPI_CALL terminator_CreateInstance(const VkInstanceCreateInfo *pCreateInfo,
 const VkAllocationCallbacks *pAllocator, VkInstance *pInstance) {
 struct loader_icd_term *icd_term = NULL;
 VkExtensionProperties *prop = NULL;
 char **filtered_extension_names = NULL;
 VkInstanceCreateInfo icd_create_info = {0};
 VkResult res = VK_SUCCESS;
 bool one_icd_successful = false;

 struct loader_instance *ptr_instance = (struct loader_instance *)*pInstance;
 if (NULL == ptr_instance) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateInstance: Loader instance pointer null encountered. Possibly set by active layer. (Policy "
 "#LLP_LAYER_21)");
 } else if (LOADER_MAGIC_NUMBER != ptr_instance->magic) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateInstance: Instance pointer (%p) has invalid MAGIC value 0x%08" PRIx64
 ". Instance value possibly "
 "corrupted by active layer (Policy #LLP_LAYER_21). ",
 ptr_instance, ptr_instance->magic);
 }

 // Save the application version if it has been modified - layers sometimes needs features in newer API versions than
 // what the application requested, and thus will increase the instance version to a level that suites their needs.
 if (pCreateInfo->pApplicationInfo && pCreateInfo->pApplicationInfo->apiVersion) {
 loader_api_version altered_version = loader_make_version(pCreateInfo->pApplicationInfo->apiVersion);
 if (altered_version.major != ptr_instance->app_api_version.major ||
 altered_version.minor != ptr_instance->app_api_version.minor) {
 ptr_instance->app_api_version = altered_version;
 }
 }

 memcpy(&icd_create_info, pCreateInfo, sizeof(icd_create_info));

 icd_create_info.enabledLayerCount = 0;
 icd_create_info.ppEnabledLayerNames = NULL;

 // NOTE: Need to filter the extensions to only those supported by the ICD.
 // No ICD will advertise support for layers. An ICD library could
 // support a layer, but it would be independent of the actual ICD,
 // just in the same library.
 uint32_t extension_count = pCreateInfo->enabledExtensionCount;
#if defined(LOADER_ENABLE_LINUX_SORT)
 extension_count += 1;
#endif // LOADER_ENABLE_LINUX_SORT
 filtered_extension_names = loader_stack_alloc(extension_count * sizeof(char *));
 if (!filtered_extension_names) {
 loader_log(ptr_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_CreateInstance: Failed create extension name array for %d extensions", extension_count);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 icd_create_info.ppEnabledExtensionNames = (const char *const *)filtered_extension_names;

 // Determine if Get Physical Device Properties 2 is available to this Instance
 if (pCreateInfo->pApplicationInfo && pCreateInfo->pApplicationInfo->apiVersion >= VK_API_VERSION_1_1) {
 ptr_instance->supports_get_dev_prop_2 = true;
 } else {
 for (uint32_t j = 0; j < pCreateInfo->enabledExtensionCount; j++) {
 if (!strcmp(pCreateInfo->ppEnabledExtensionNames[j], VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME)) {
 ptr_instance->supports_get_dev_prop_2 = true;
 break;
 }
 }
 }

 for (uint32_t i = 0; i < ptr_instance->icd_tramp_list.count; i++) {
 icd_term = loader_icd_add(ptr_instance, &ptr_instance->icd_tramp_list.scanned_list[i]);
 if (NULL == icd_term) {
 loader_log(ptr_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_CreateInstance: Failed to add ICD %d to ICD trampoline list.", i);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 // If any error happens after here, we need to remove the ICD from the list,
 // because we've already added it, but haven't validated it

 // Make sure that we reset the pApplicationInfo so we don't get an old pointer
 icd_create_info.pApplicationInfo = pCreateInfo->pApplicationInfo;
 icd_create_info.enabledExtensionCount = 0;
 struct loader_extension_list icd_exts = {0};

 // traverse scanned icd list adding non-duplicate extensions to the list
 res = loader_init_generic_list(ptr_instance, (struct loader_generic_list *)&icd_exts, sizeof(VkExtensionProperties));
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 // If out of memory, bail immediately.
 goto out;
 } else if (VK_SUCCESS != res) {
 // Something bad happened with this ICD, so free it and try the
 // next.
 ptr_instance->icd_terms = icd_term->next;
 icd_term->next = NULL;
 loader_icd_destroy(ptr_instance, icd_term, pAllocator);
 continue;
 }

 res = loader_add_instance_extensions(ptr_instance, icd_term->scanned_icd->EnumerateInstanceExtensionProperties,
 icd_term->scanned_icd->lib_name, &icd_exts);
 if (VK_SUCCESS != res) {
 loader_destroy_generic_list(ptr_instance, (struct loader_generic_list *)&icd_exts);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 // If out of memory, bail immediately.
 goto out;
 } else {
 // Something bad happened with this ICD, so free it and try the next.
 ptr_instance->icd_terms = icd_term->next;
 icd_term->next = NULL;
 loader_icd_destroy(ptr_instance, icd_term, pAllocator);
 continue;
 }
 }

 for (uint32_t j = 0; j < pCreateInfo->enabledExtensionCount; j++) {
 prop = get_extension_property(pCreateInfo->ppEnabledExtensionNames[j], &icd_exts);
 if (prop) {
 filtered_extension_names[icd_create_info.enabledExtensionCount] = (char *)pCreateInfo->ppEnabledExtensionNames[j];
 icd_create_info.enabledExtensionCount++;
 }
 }
#if defined(LOADER_ENABLE_LINUX_SORT)
 // Force on "VK_KHR_get_physical_device_properties2" for Linux as we use it for GPU sorting. This
 // should be done if the API version of either the application or the driver does not natively support
 // the core version of vkGetPhysicalDeviceProperties2 entrypoint.
 if ((ptr_instance->app_api_version.major == 1 && ptr_instance->app_api_version.minor == 0) ||
 (VK_API_VERSION_MAJOR(icd_term->scanned_icd->api_version) == 1 &&
 VK_API_VERSION_MINOR(icd_term->scanned_icd->api_version) == 0)) {
 prop = get_extension_property(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME, &icd_exts);
 if (prop) {
 filtered_extension_names[icd_create_info.enabledExtensionCount] =
 (char *)VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME;
 icd_create_info.enabledExtensionCount++;

 // At least one ICD supports this, so the instance should be able to support it
 ptr_instance->supports_get_dev_prop_2 = true;
 }
 }
#endif // LOADER_ENABLE_LINUX_SORT

 // Determine if vkGetPhysicalDeviceProperties2 is available to this Instance
 // Also determine if VK_EXT_surface_maintenance1 is available on the ICD
 if (icd_term->scanned_icd->api_version >= VK_API_VERSION_1_1) {
 icd_term->enabled_instance_extensions.khr_get_physical_device_properties2 = true;
 }
 fill_out_enabled_instance_extensions(icd_create_info.enabledExtensionCount, (const char *const *)filtered_extension_names,
 &icd_term->enabled_instance_extensions);

 loader_destroy_generic_list(ptr_instance, (struct loader_generic_list *)&icd_exts);

 // Get the driver version from vkEnumerateInstanceVersion
 uint32_t icd_version = VK_API_VERSION_1_0;
 VkResult icd_result = VK_SUCCESS;
 if (icd_term->scanned_icd->api_version >= VK_API_VERSION_1_1) {
 PFN_vkEnumerateInstanceVersion icd_enumerate_instance_version =
 (PFN_vkEnumerateInstanceVersion)icd_term->scanned_icd->GetInstanceProcAddr(NULL, "vkEnumerateInstanceVersion");
 if (icd_enumerate_instance_version != NULL) {
 icd_result = icd_enumerate_instance_version(&icd_version);
 if (icd_result != VK_SUCCESS) {
 icd_version = VK_API_VERSION_1_0;
 loader_log(ptr_instance, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateInstance: ICD \"%s\" vkEnumerateInstanceVersion returned error. The ICD will be "
 "treated as a 1.0 ICD",
 icd_term->scanned_icd->lib_name);
 } else if (VK_API_VERSION_MINOR(icd_version) == 0) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateInstance: Manifest ICD for \"%s\" contained a 1.1 or greater API version, but "
 "vkEnumerateInstanceVersion returned 1.0, treating as a 1.0 ICD",
 icd_term->scanned_icd->lib_name);
 }
 } else {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateInstance: Manifest ICD for \"%s\" contained a 1.1 or greater API version, but does "
 "not support vkEnumerateInstanceVersion, treating as a 1.0 ICD",
 icd_term->scanned_icd->lib_name);
 }
 }

 // Remove the portability enumeration flag bit if the ICD doesn't support the extension
 if ((pCreateInfo->flags & VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR) == 1) {
 bool supports_portability_enumeration = false;
 for (uint32_t j = 0; j < icd_create_info.enabledExtensionCount; j++) {
 if (strcmp(filtered_extension_names[j], VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME) == 0) {
 supports_portability_enumeration = true;
 break;
 }
 }
 // If the icd supports the extension, use the flags as given, otherwise remove the portability bit
 icd_create_info.flags = supports_portability_enumeration
 ? pCreateInfo->flags
 : pCreateInfo->flags & (~VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR);
 }

 // Create an instance, substituting the version to 1.0 if necessary
 VkApplicationInfo icd_app_info = {0};
 const uint32_t api_variant = 0;
 const uint32_t api_version_1_0 = VK_API_VERSION_1_0;
 uint32_t icd_version_nopatch =
 VK_MAKE_API_VERSION(api_variant, VK_API_VERSION_MAJOR(icd_version), VK_API_VERSION_MINOR(icd_version), 0);
 uint32_t requested_version = (pCreateInfo == NULL || pCreateInfo->pApplicationInfo == NULL)
 ? api_version_1_0
 : pCreateInfo->pApplicationInfo->apiVersion;
 if ((requested_version != 0) && (icd_version_nopatch == api_version_1_0)) {
 if (icd_create_info.pApplicationInfo == NULL) {
 memset(&icd_app_info, 0, sizeof(icd_app_info));
 } else {
 memmove(&icd_app_info, icd_create_info.pApplicationInfo, sizeof(icd_app_info));
 }
 icd_app_info.apiVersion = icd_version;
 icd_create_info.pApplicationInfo = &icd_app_info;
 }

 // If the settings file has device_configurations, we need to raise the ApiVersion drivers use to 1.1 if the driver
 // supports 1.1 or higher. This allows 1.0 apps to use the device_configurations without the app having to set its own
 // ApiVersion to 1.1 on its own.
 if (ptr_instance->settings.settings_active && ptr_instance->settings.device_configurations_active &&
 ptr_instance->settings.device_configuration_count > 0 && icd_version >= VK_API_VERSION_1_1 &&
 requested_version < VK_API_VERSION_1_1) {
 if (NULL != pCreateInfo->pApplicationInfo) {
 memcpy(&icd_app_info, pCreateInfo->pApplicationInfo, sizeof(VkApplicationInfo));
 }
 icd_app_info.apiVersion = VK_API_VERSION_1_1;
 icd_create_info.pApplicationInfo = &icd_app_info;

 loader_log(
 ptr_instance, VULKAN_LOADER_INFO_BIT, 0,
 "terminator_CreateInstance: Raising the VkApplicationInfo::apiVersion from 1.0 to 1.1 on driver \"%s\" so that "
 "the loader settings file is able to use this driver in the device_configuration selection logic.",
 icd_term->scanned_icd->lib_name);
 }

 icd_result =
 ptr_instance->icd_tramp_list.scanned_list[i].CreateInstance(&icd_create_info, pAllocator, &(icd_term->instance));
 if (VK_ERROR_OUT_OF_HOST_MEMORY == icd_result) {
 // If out of memory, bail immediately.
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 } else if (VK_SUCCESS != icd_result) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateInstance: Received return code %i from call to vkCreateInstance in ICD %s. Skipping "
 "this driver.",
 icd_result, icd_term->scanned_icd->lib_name);
 ptr_instance->icd_terms = icd_term->next;
 icd_term->next = NULL;
 loader_icd_destroy(ptr_instance, icd_term, pAllocator);
 continue;
 }

 if (!loader_icd_init_entries(ptr_instance, icd_term)) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateInstance: Failed to find required entrypoints in ICD %s. Skipping this driver.",
 icd_term->scanned_icd->lib_name);
 ptr_instance->icd_terms = icd_term->next;
 icd_term->next = NULL;
 loader_icd_destroy(ptr_instance, icd_term, pAllocator);
 continue;
 }

 if (ptr_instance->icd_tramp_list.scanned_list[i].interface_version < 3 &&
 (
#if defined(VK_USE_PLATFORM_XLIB_KHR)
 NULL != icd_term->dispatch.CreateXlibSurfaceKHR ||
#endif // VK_USE_PLATFORM_XLIB_KHR
#if defined(VK_USE_PLATFORM_XCB_KHR)
 NULL != icd_term->dispatch.CreateXcbSurfaceKHR ||
#endif // VK_USE_PLATFORM_XCB_KHR
#if defined(VK_USE_PLATFORM_WAYLAND_KHR)
 NULL != icd_term->dispatch.CreateWaylandSurfaceKHR ||
#endif // VK_USE_PLATFORM_WAYLAND_KHR
#if defined(VK_USE_PLATFORM_ANDROID_KHR)
 NULL != icd_term->dispatch.CreateAndroidSurfaceKHR ||
#endif // VK_USE_PLATFORM_ANDROID_KHR
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 NULL != icd_term->dispatch.CreateWin32SurfaceKHR ||
#endif // VK_USE_PLATFORM_WIN32_KHR
 NULL != icd_term->dispatch.DestroySurfaceKHR)) {
 loader_log(ptr_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateInstance: Driver %s supports interface version %u but still exposes VkSurfaceKHR"
 " create/destroy entrypoints (Policy #LDP_DRIVER_8)",
 ptr_instance->icd_tramp_list.scanned_list[i].lib_name,
 ptr_instance->icd_tramp_list.scanned_list[i].interface_version);
 }

 // If we made it this far, at least one ICD was successful
 one_icd_successful = true;
 }

 // For vkGetPhysicalDeviceProperties2, at least one ICD needs to support the extension for the
 // instance to have it
 if (ptr_instance->enabled_extensions.khr_get_physical_device_properties2) {
 bool at_least_one_supports = false;
 icd_term = ptr_instance->icd_terms;
 while (icd_term != NULL) {
 if (icd_term->enabled_instance_extensions.khr_get_physical_device_properties2) {
 at_least_one_supports = true;
 break;
 }
 icd_term = icd_term->next;
 }
 if (!at_least_one_supports) {
 ptr_instance->enabled_extensions.khr_get_physical_device_properties2 = false;
 }
 }

 // If no ICDs were added to instance list and res is unchanged from it's initial value, the loader was unable to
 // find a suitable ICD.
 if (VK_SUCCESS == res && (ptr_instance->icd_terms == NULL || !one_icd_successful)) {
 loader_log(ptr_instance, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateInstance: Found no drivers!");
 res = VK_ERROR_INCOMPATIBLE_DRIVER;
 }

out:

 ptr_instance->create_terminator_invalid_extension = false;

 if (VK_SUCCESS != res) {
 if (VK_ERROR_EXTENSION_NOT_PRESENT == res) {
 ptr_instance->create_terminator_invalid_extension = true;
 }

 while (NULL != ptr_instance->icd_terms) {
 icd_term = ptr_instance->icd_terms;
 ptr_instance->icd_terms = icd_term->next;
 if (NULL != icd_term->instance) {
 loader_icd_close_objects(ptr_instance, icd_term);
 icd_term->dispatch.DestroyInstance(icd_term->instance, pAllocator);
 }
 loader_icd_destroy(ptr_instance, icd_term, pAllocator);
 }
 } else {
 // Check for enabled extensions here to setup the loader structures so the loader knows what extensions
 // it needs to worry about.
 // We do it here and again above the layers in the trampoline function since the trampoline function
 // may think different extensions are enabled than what's down here.
 // This is why we don't clear inside of these function calls.
 // The clearing should actually be handled by the overall memset of the pInstance structure in the
 // trampoline.
 fill_out_enabled_instance_extensions(pCreateInfo->enabledExtensionCount, pCreateInfo->ppEnabledExtensionNames,
 &ptr_instance->enabled_extensions);
 }

 return res;
}

VKAPI_ATTR void VKAPI_CALL terminator_DestroyInstance(VkInstance instance, const VkAllocationCallbacks *pAllocator) {
 struct loader_instance *ptr_instance = loader_get_instance(instance);
 if (NULL == ptr_instance) {
 return;
 }

 // Remove this instance from the list of instances:
 struct loader_instance *prev = NULL;
 struct loader_instance *next = loader.instances;
 while (next != NULL) {
 if (next == ptr_instance) {
 // Remove this instance from the list:
 if (prev)
 prev->next = next->next;
 else
 loader.instances = next->next;
 break;
 }
 prev = next;
 next = next->next;
 }

 struct loader_icd_term *icd_terms = ptr_instance->icd_terms;
 while (NULL != icd_terms) {
 if (icd_terms->instance) {
 loader_icd_close_objects(ptr_instance, icd_terms);
 icd_terms->dispatch.DestroyInstance(icd_terms->instance, pAllocator);
 }
 struct loader_icd_term *next_icd_term = icd_terms->next;
 icd_terms->instance = VK_NULL_HANDLE;
 loader_icd_destroy(ptr_instance, icd_terms, pAllocator);

 icd_terms = next_icd_term;
 }

 loader_clear_scanned_icd_list(ptr_instance, &ptr_instance->icd_tramp_list);
 loader_destroy_generic_list(ptr_instance, (struct loader_generic_list *)&ptr_instance->ext_list);
 if (NULL != ptr_instance->phys_devs_term) {
 for (uint32_t i = 0; i < ptr_instance->phys_dev_count_term; i++) {
 for (uint32_t j = i + 1; j < ptr_instance->phys_dev_count_term; j++) {
 if (ptr_instance->phys_devs_term[i] == ptr_instance->phys_devs_term[j]) {
 ptr_instance->phys_devs_term[j] = NULL;
 }
 }
 }
 for (uint32_t i = 0; i < ptr_instance->phys_dev_count_term; i++) {
 loader_instance_heap_free(ptr_instance, ptr_instance->phys_devs_term[i]);
 }
 loader_instance_heap_free(ptr_instance, ptr_instance->phys_devs_term);
 }
 if (NULL != ptr_instance->phys_dev_groups_term) {
 for (uint32_t i = 0; i < ptr_instance->phys_dev_group_count_term; i++) {
 loader_instance_heap_free(ptr_instance, ptr_instance->phys_dev_groups_term[i]);
 }
 loader_instance_heap_free(ptr_instance, ptr_instance->phys_dev_groups_term);
 }
 loader_free_dev_ext_table(ptr_instance);
 loader_free_phys_dev_ext_table(ptr_instance);

 free_string_list(ptr_instance, &ptr_instance->enabled_layer_names);
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_CreateDevice(VkPhysicalDevice physicalDevice, const VkDeviceCreateInfo *pCreateInfo,
 const VkAllocationCallbacks *pAllocator, VkDevice *pDevice) {
 VkResult res = VK_SUCCESS;
 struct loader_physical_device_term *phys_dev_term;
 phys_dev_term = (struct loader_physical_device_term *)physicalDevice;
 struct loader_icd_term *icd_term = phys_dev_term->this_icd_term;

 struct loader_device *dev = (struct loader_device *)*pDevice;
 PFN_vkCreateDevice fpCreateDevice = icd_term->dispatch.CreateDevice;
 struct loader_extension_list icd_exts;

 VkBaseOutStructure *caller_dgci_container = NULL;
 VkDeviceGroupDeviceCreateInfo *caller_dgci = NULL;

 if (NULL == dev) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateDevice: Loader device pointer null encountered. Possibly set by active layer. (Policy "
 "#LLP_LAYER_22)");
 } else if (DEVICE_DISP_TABLE_MAGIC_NUMBER != dev->loader_dispatch.core_dispatch.magic) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_WARN_BIT, 0,
 "terminator_CreateDevice: Device pointer (%p) has invalid MAGIC value 0x%08" PRIx64
 ". The expected value is "
 "0x10ADED040410ADED. Device value possibly "
 "corrupted by active layer (Policy #LLP_LAYER_22). ",
 dev, dev->loader_dispatch.core_dispatch.magic);
 }

 dev->phys_dev_term = phys_dev_term;

 icd_exts.list = NULL;

 if (fpCreateDevice == NULL) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateDevice: No vkCreateDevice command exposed by ICD %s", icd_term->scanned_icd->lib_name);
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 VkDeviceCreateInfo localCreateInfo;
 memcpy(&localCreateInfo, pCreateInfo, sizeof(localCreateInfo));

 // NOTE: Need to filter the extensions to only those supported by the ICD.
 // No ICD will advertise support for layers. An ICD library could support a layer,
 // but it would be independent of the actual ICD, just in the same library.
 char **filtered_extension_names = NULL;
 if (0 < pCreateInfo->enabledExtensionCount) {
 filtered_extension_names = loader_stack_alloc(pCreateInfo->enabledExtensionCount * sizeof(char *));
 if (NULL == filtered_extension_names) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_CreateDevice: Failed to create extension name storage for %d extensions",
 pCreateInfo->enabledExtensionCount);
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 }

 localCreateInfo.enabledLayerCount = 0;
 localCreateInfo.ppEnabledLayerNames = NULL;

 localCreateInfo.enabledExtensionCount = 0;
 localCreateInfo.ppEnabledExtensionNames = (const char *const *)filtered_extension_names;

 // Get the physical device (ICD) extensions
 res = loader_init_generic_list(icd_term->this_instance, (struct loader_generic_list *)&icd_exts, sizeof(VkExtensionProperties));
 if (VK_SUCCESS != res) {
 goto out;
 }

 res = loader_add_device_extensions(icd_term->this_instance, icd_term->dispatch.EnumerateDeviceExtensionProperties,
 phys_dev_term->phys_dev, icd_term->scanned_icd->lib_name, &icd_exts);
 if (res != VK_SUCCESS) {
 goto out;
 }

 for (uint32_t i = 0; i < pCreateInfo->enabledExtensionCount; i++) {
 if (pCreateInfo->ppEnabledExtensionNames == NULL) {
 continue;
 }
 const char *extension_name = pCreateInfo->ppEnabledExtensionNames[i];
 if (extension_name == NULL) {
 continue;
 }
 VkExtensionProperties *prop = get_extension_property(extension_name, &icd_exts);
 if (prop) {
 filtered_extension_names[localCreateInfo.enabledExtensionCount] = (char *)extension_name;
 localCreateInfo.enabledExtensionCount++;
 } else {
 loader_log(icd_term->this_instance, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "vkCreateDevice extension %s not available for devices associated with ICD %s", extension_name,
 icd_term->scanned_icd->lib_name);
 }
 }

 // Before we continue, If KHX_device_group is the list of enabled and viable extensions, then we then need to look for the
 // corresponding VkDeviceGroupDeviceCreateInfo struct in the device list and replace all the physical device values (which
 // are really loader physical device terminator values) with the ICD versions.
 // if (icd_term->this_instance->enabled_extensions.khr_device_group_creation == 1) {
 {
 VkBaseOutStructure *pNext = (VkBaseOutStructure *)localCreateInfo.pNext;
 VkBaseOutStructure *pPrev = (VkBaseOutStructure *)&localCreateInfo;
 while (NULL != pNext) {
 if (VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO == pNext->sType) {
 VkDeviceGroupDeviceCreateInfo *cur_struct = (VkDeviceGroupDeviceCreateInfo *)pNext;
 if (0 < cur_struct->physicalDeviceCount && NULL != cur_struct->pPhysicalDevices) {
 VkDeviceGroupDeviceCreateInfo *temp_struct = loader_stack_alloc(sizeof(VkDeviceGroupDeviceCreateInfo));
 VkPhysicalDevice *phys_dev_array = NULL;
 if (NULL == temp_struct) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 memcpy(temp_struct, cur_struct, sizeof(VkDeviceGroupDeviceCreateInfo));
 phys_dev_array = loader_stack_alloc(sizeof(VkPhysicalDevice) * cur_struct->physicalDeviceCount);
 if (NULL == phys_dev_array) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 // Before calling down, replace the incoming physical device values (which are really loader terminator
 // physical devices) with the ICDs physical device values.
 struct loader_physical_device_term *cur_term;
 for (uint32_t phys_dev = 0; phys_dev < cur_struct->physicalDeviceCount; phys_dev++) {
 cur_term = (struct loader_physical_device_term *)cur_struct->pPhysicalDevices[phys_dev];
 phys_dev_array[phys_dev] = cur_term->phys_dev;
 }
 temp_struct->pPhysicalDevices = phys_dev_array;

 // Keep track of pointers to restore pNext chain before returning
 caller_dgci_container = pPrev;
 caller_dgci = cur_struct;

 // Replace the old struct in the pNext chain with this one.
 pPrev->pNext = (VkBaseOutStructure *)temp_struct;
 }
 break;
 }

 pPrev = pNext;
 pNext = pNext->pNext;
 }
 }

 // Handle loader emulation for structs that are not supported by the ICD:
 // Presently, the emulation leaves the pNext chain alone. This means that the ICD will receive items in the chain which
 // are not recognized by the ICD. If this causes the ICD to fail, then the items would have to be removed here. The current
 // implementation does not remove them because copying the pNext chain would be impossible if the loader does not recognize
 // the any of the struct types, as the loader would not know the size to allocate and copy.
 // if (icd_term->dispatch.GetPhysicalDeviceFeatures2 == NULL && icd_term->dispatch.GetPhysicalDeviceFeatures2KHR == NULL) {
 {
 const void *pNext = localCreateInfo.pNext;
 while (pNext != NULL) {
 VkBaseInStructure pNext_in_structure = {0};
 memcpy(&pNext_in_structure, pNext, sizeof(VkBaseInStructure));
 switch (pNext_in_structure.sType) {
 case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2: {
 const VkPhysicalDeviceFeatures2KHR *features = pNext;

 if (icd_term->dispatch.GetPhysicalDeviceFeatures2 == NULL &&
 icd_term->dispatch.GetPhysicalDeviceFeatures2KHR == NULL) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_INFO_BIT, 0,
 "vkCreateDevice: Emulating handling of VkPhysicalDeviceFeatures2 in pNext chain for ICD \"%s\"",
 icd_term->scanned_icd->lib_name);

 // Verify that VK_KHR_get_physical_device_properties2 is enabled
 if (icd_term->this_instance->enabled_extensions.khr_get_physical_device_properties2) {
 localCreateInfo.pEnabledFeatures = &features->features;
 }
 }

 // Leave this item in the pNext chain for now

 pNext = features->pNext;
 break;
 }

 case VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO: {
 const VkDeviceGroupDeviceCreateInfo *group_info = pNext;

 if (icd_term->dispatch.EnumeratePhysicalDeviceGroups == NULL &&
 icd_term->dispatch.EnumeratePhysicalDeviceGroupsKHR == NULL) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_INFO_BIT, 0,
 "vkCreateDevice: Emulating handling of VkPhysicalDeviceGroupProperties in pNext chain for "
 "ICD \"%s\"",
 icd_term->scanned_icd->lib_name);

 // The group must contain only this one device, since physical device groups aren't actually supported
 if (group_info->physicalDeviceCount != 1) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_ERROR_BIT, 0,
 "vkCreateDevice: Emulation failed to create device from device group info");
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 }

 // Nothing needs to be done here because we're leaving the item in the pNext chain and because the spec
 // states that the physicalDevice argument must be included in the device group, and we've already checked
 // that it is

 pNext = group_info->pNext;
 break;
 }

 // Multiview properties are also allowed, but since VK_KHX_multiview is a device extension, we'll just let the
 // ICD handle that error when the user enables the extension here
 default: {
 pNext = pNext_in_structure.pNext;
 break;
 }
 }
 }
 }

 VkBool32 maintenance5_feature_enabled = false;
 // Look for the VkPhysicalDeviceMaintenance5FeaturesKHR struct to see if the feature was enabled
 {
 const void *pNext = localCreateInfo.pNext;
 while (pNext != NULL) {
 VkBaseInStructure pNext_in_structure = {0};
 memcpy(&pNext_in_structure, pNext, sizeof(VkBaseInStructure));
 switch (pNext_in_structure.sType) {
 case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MAINTENANCE_5_FEATURES_KHR: {
 const VkPhysicalDeviceMaintenance5FeaturesKHR *maintenance_features = pNext;
 if (maintenance_features->maintenance5 == VK_TRUE) {
 maintenance5_feature_enabled = true;
 }
 pNext = maintenance_features->pNext;
 break;
 }

 default: {
 pNext = pNext_in_structure.pNext;
 break;
 }
 }
 }
 }

 // Every extension that has a loader-defined terminator needs to be marked as enabled or disabled so that we know whether or
 // not to return that terminator when vkGetDeviceProcAddr is called
 for (uint32_t i = 0; i < localCreateInfo.enabledExtensionCount; ++i) {
 if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_KHR_SWAPCHAIN_EXTENSION_NAME)) {
 dev->driver_extensions.khr_swapchain_enabled = true;
 } else if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_KHR_DISPLAY_SWAPCHAIN_EXTENSION_NAME)) {
 dev->driver_extensions.khr_display_swapchain_enabled = true;
 } else if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_KHR_DEVICE_GROUP_EXTENSION_NAME)) {
 dev->driver_extensions.khr_device_group_enabled = true;
 } else if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_EXT_DEBUG_MARKER_EXTENSION_NAME)) {
 dev->driver_extensions.ext_debug_marker_enabled = true;
#if defined(VK_USE_PLATFORM_WIN32_KHR)
 } else if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_EXT_FULL_SCREEN_EXCLUSIVE_EXTENSION_NAME)) {
 dev->driver_extensions.ext_full_screen_exclusive_enabled = true;
#endif
 } else if (!strcmp(localCreateInfo.ppEnabledExtensionNames[i], VK_KHR_MAINTENANCE_5_EXTENSION_NAME) &&
 maintenance5_feature_enabled) {
 dev->should_ignore_device_commands_from_newer_version = true;
 }
 }
 dev->layer_extensions.ext_debug_utils_enabled = icd_term->this_instance->enabled_extensions.ext_debug_utils;
 dev->driver_extensions.ext_debug_utils_enabled = icd_term->this_instance->enabled_extensions.ext_debug_utils;

 VkPhysicalDeviceProperties properties;
 icd_term->dispatch.GetPhysicalDeviceProperties(phys_dev_term->phys_dev, &properties);

 loader_log(icd_term->this_instance, VULKAN_LOADER_LAYER_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 " Using \"%s\" with driver: \"%s\"", properties.deviceName, icd_term->scanned_icd->lib_name);

 res = fpCreateDevice(phys_dev_term->phys_dev, &localCreateInfo, pAllocator, &dev->icd_device);
 if (res != VK_SUCCESS) {
 loader_log(icd_term->this_instance, VULKAN_LOADER_ERROR_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "terminator_CreateDevice: Failed in ICD %s vkCreateDevice call", icd_term->scanned_icd->lib_name);
 goto out;
 }

 *pDevice = dev->icd_device;
 loader_add_logical_device(icd_term, dev);

 // Init dispatch pointer in new device object
 loader_init_dispatch(*pDevice, &dev->loader_dispatch);

out:
 if (NULL != icd_exts.list) {
 loader_destroy_generic_list(icd_term->this_instance, (struct loader_generic_list *)&icd_exts);
 }

 // Restore pNext pointer to old VkDeviceGroupDeviceCreateInfo
 // in the chain to maintain consistency for the caller.
 if (caller_dgci_container != NULL) {
 caller_dgci_container->pNext = (VkBaseOutStructure *)caller_dgci;
 }

 return res;
}

// Update the trampoline physical devices with the wrapped version.
// We always want to re-use previous physical device pointers since they may be used by an application
// after returning previously.
VkResult setup_loader_tramp_phys_devs(struct loader_instance *inst, uint32_t phys_dev_count, VkPhysicalDevice *phys_devs) {
 VkResult res = VK_SUCCESS;
 uint32_t found_count = 0;
 uint32_t old_count = inst->phys_dev_count_tramp;
 uint32_t new_count = inst->total_gpu_count;
 struct loader_physical_device_tramp **new_phys_devs = NULL;

 if (0 == phys_dev_count) {
 return VK_SUCCESS;
 }
 if (phys_dev_count > new_count) {
 new_count = phys_dev_count;
 }

 // We want an old to new index array and a new to old index array
 int32_t *old_to_new_index = (int32_t *)loader_stack_alloc(sizeof(int32_t) * old_count);
 int32_t *new_to_old_index = (int32_t *)loader_stack_alloc(sizeof(int32_t) * new_count);
 if (NULL == old_to_new_index || NULL == new_to_old_index) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 // Initialize both
 for (uint32_t cur_idx = 0; cur_idx < old_count; ++cur_idx) {
 old_to_new_index[cur_idx] = -1;
 }
 for (uint32_t cur_idx = 0; cur_idx < new_count; ++cur_idx) {
 new_to_old_index[cur_idx] = -1;
 }

 // Figure out the old->new and new->old indices
 for (uint32_t cur_idx = 0; cur_idx < old_count; ++cur_idx) {
 for (uint32_t new_idx = 0; new_idx < phys_dev_count; ++new_idx) {
 if (inst->phys_devs_tramp[cur_idx]->phys_dev == phys_devs[new_idx]) {
 old_to_new_index[cur_idx] = (int32_t)new_idx;
 new_to_old_index[new_idx] = (int32_t)cur_idx;
 found_count++;
 break;
 }
 }
 }

 // If we found exactly the number of items we were looking for as we had before. Then everything
 // we already have is good enough and we just need to update the array that was passed in with
 // the loader values.
 if (found_count == phys_dev_count && 0 != old_count && old_count == new_count) {
 for (uint32_t new_idx = 0; new_idx < phys_dev_count; ++new_idx) {
 for (uint32_t cur_idx = 0; cur_idx < old_count; ++cur_idx) {
 if (old_to_new_index[cur_idx] == (int32_t)new_idx) {
 phys_devs[new_idx] = (VkPhysicalDevice)inst->phys_devs_tramp[cur_idx];
 break;
 }
 }
 }
 // Nothing else to do for this path
 res = VK_SUCCESS;
 } else {
 // Something is different, so do the full path of checking every device and creating a new array to use.
 // This can happen if a device was added, or removed, or we hadn't previously queried all the data and we
 // have more to store.
 new_phys_devs = loader_instance_heap_calloc(inst, sizeof(struct loader_physical_device_tramp *) * new_count,
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_devs) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_tramp_phys_devs: Failed to allocate new physical device array of size %d", new_count);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 if (new_count > phys_dev_count) {
 found_count = phys_dev_count;
 } else {
 found_count = new_count;
 }

 // First try to see if an old item exists that matches the new item. If so, just copy it over.
 for (uint32_t new_idx = 0; new_idx < found_count; ++new_idx) {
 bool old_item_found = false;
 for (uint32_t cur_idx = 0; cur_idx < old_count; ++cur_idx) {
 if (old_to_new_index[cur_idx] == (int32_t)new_idx) {
 // Copy over old item to correct spot in the new array
 new_phys_devs[new_idx] = inst->phys_devs_tramp[cur_idx];
 old_item_found = true;
 break;
 }
 }
 // Something wasn't found, so it's new so add it to the new list
 if (!old_item_found) {
 new_phys_devs[new_idx] = loader_instance_heap_alloc(inst, sizeof(struct loader_physical_device_tramp),
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_devs[new_idx]) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_tramp_phys_devs: Failed to allocate new trampoline physical device");
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 // Initialize the new physicalDevice object
 loader_set_dispatch((void *)new_phys_devs[new_idx], inst->disp);
 new_phys_devs[new_idx]->this_instance = inst;
 new_phys_devs[new_idx]->phys_dev = phys_devs[new_idx];
 new_phys_devs[new_idx]->magic = PHYS_TRAMP_MAGIC_NUMBER;
 }

 phys_devs[new_idx] = (VkPhysicalDevice)new_phys_devs[new_idx];
 }

 // We usually get here if the user array is smaller than the total number of devices, so copy the
 // remaining devices we have over to the new array.
 uint32_t start = found_count;
 for (uint32_t new_idx = start; new_idx < new_count; ++new_idx) {
 for (uint32_t cur_idx = 0; cur_idx < old_count; ++cur_idx) {
 if (old_to_new_index[cur_idx] == -1) {
 new_phys_devs[new_idx] = inst->phys_devs_tramp[cur_idx];
 old_to_new_index[cur_idx] = new_idx;
 found_count++;
 break;
 }
 }
 }
 }

out:

 if (NULL != new_phys_devs) {
 if (VK_SUCCESS != res) {
 for (uint32_t new_idx = 0; new_idx < found_count; ++new_idx) {
 // If an OOM occurred inside the copying of the new physical devices into the existing array
 // will leave some of the old physical devices in the array which may have been copied into
 // the new array, leading to them being freed twice. To avoid this we just make sure to not
 // delete physical devices which were copied.
 bool found = false;
 for (uint32_t cur_idx = 0; cur_idx < inst->phys_dev_count_tramp; cur_idx++) {
 if (new_phys_devs[new_idx] == inst->phys_devs_tramp[cur_idx]) {
 found = true;
 break;
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, new_phys_devs[new_idx]);
 }
 }
 loader_instance_heap_free(inst, new_phys_devs);
 } else {
 if (new_count > inst->total_gpu_count) {
 inst->total_gpu_count = new_count;
 }
 // Free everything in the old array that was not copied into the new array
 // here. We can't attempt to do that before here since the previous loop
 // looking before the "out:" label may hit an out of memory condition resulting
 // in memory leaking.
 if (NULL != inst->phys_devs_tramp) {
 for (uint32_t i = 0; i < inst->phys_dev_count_tramp; i++) {
 bool found = false;
 for (uint32_t j = 0; j < inst->total_gpu_count; j++) {
 if (inst->phys_devs_tramp[i] == new_phys_devs[j]) {
 found = true;
 break;
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, inst->phys_devs_tramp[i]);
 }
 }
 loader_instance_heap_free(inst, inst->phys_devs_tramp);
 }
 inst->phys_devs_tramp = new_phys_devs;
 inst->phys_dev_count_tramp = found_count;
 }
 }
 if (VK_SUCCESS != res) {
 inst->total_gpu_count = 0;
 }

 return res;
}

#if defined(LOADER_ENABLE_LINUX_SORT)
bool is_linux_sort_enabled(struct loader_instance *inst) {
 bool sort_items = inst->supports_get_dev_prop_2;
 char *env_value = loader_getenv("VK_LOADER_DISABLE_SELECT", inst);
 if (NULL != env_value) {
 int32_t int_env_val = atoi(env_value);
 loader_free_getenv(env_value, inst);
 if (int_env_val != 0) {
 sort_items = false;
 }
 }
 return sort_items;
}
#endif // LOADER_ENABLE_LINUX_SORT

// Look for physical_device in the provided phys_devs list, return true if found and put the index into out_idx, otherwise
// return false
bool find_phys_dev(VkPhysicalDevice physical_device, uint32_t phys_devs_count, struct loader_physical_device_term **phys_devs,
 uint32_t *out_idx) {
 if (NULL == phys_devs) return false;
 for (uint32_t idx = 0; idx < phys_devs_count; idx++) {
 if (NULL != phys_devs[idx] && physical_device == phys_devs[idx]->phys_dev) {
 *out_idx = idx;
 return true;
 }
 }
 return false;
}

// Add physical_device to new_phys_devs
VkResult check_and_add_to_new_phys_devs(struct loader_instance *inst, VkPhysicalDevice physical_device,
 struct loader_icd_physical_devices *dev_array, uint32_t *cur_new_phys_dev_count,
 struct loader_physical_device_term **new_phys_devs) {
 uint32_t out_idx = 0;
 uint32_t idx = *cur_new_phys_dev_count;
 // Check if the physical_device already exists in the new_phys_devs buffer, that means it was found from both
 // EnumerateAdapterPhysicalDevices and EnumeratePhysicalDevices and we need to skip it.
 if (find_phys_dev(physical_device, idx, new_phys_devs, &out_idx)) {
 return VK_SUCCESS;
 }
 // Check if it was found in a previous call to vkEnumeratePhysicalDevices, we can just copy over the old data.
 if (find_phys_dev(physical_device, inst->phys_dev_count_term, inst->phys_devs_term, &out_idx)) {
 new_phys_devs[idx] = inst->phys_devs_term[out_idx];
 (*cur_new_phys_dev_count)++;
 return VK_SUCCESS;
 }

 // Exit in case something is already present - this shouldn't happen but better to be safe than overwrite existing data
 // since this code has been refactored a half dozen times.
 if (NULL != new_phys_devs[idx]) {
 return VK_SUCCESS;
 }
 // If this physical device is new, we need to allocate space for it.
 new_phys_devs[idx] =
 loader_instance_heap_alloc(inst, sizeof(struct loader_physical_device_term), VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_devs[idx]) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "check_and_add_to_new_phys_devs: Failed to allocate physical device terminator object %d", idx);
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 loader_set_dispatch((void *)new_phys_devs[idx], inst->disp);
 new_phys_devs[idx]->this_icd_term = dev_array->icd_term;
 new_phys_devs[idx]->phys_dev = physical_device;

 // Increment the count of new physical devices
 (*cur_new_phys_dev_count)++;
 return VK_SUCCESS;
}

/* Enumerate all physical devices from ICDs and add them to inst->phys_devs_term
 *
 * There are two methods to find VkPhysicalDevices - vkEnumeratePhysicalDevices and vkEnumerateAdapterPhysicalDevices
 * The latter is supported on windows only and on devices supporting ICD Interface Version 6 and greater.
 *
 * Once all physical devices are acquired, they need to be pulled into a single list of `loader_physical_device_term`'s.
 * They also need to be setup - the icd_term, icd_index, phys_dev, and disp (dispatch table) all need the correct data.
 * Additionally, we need to keep using already setup physical devices as they may be in use, thus anything enumerated
 * that is already in inst->phys_devs_term will be carried over.
 */

VkResult setup_loader_term_phys_devs(struct loader_instance *inst) {
 VkResult res = VK_SUCCESS;
 struct loader_icd_term *icd_term;
 uint32_t windows_sorted_devices_count = 0;
 struct loader_icd_physical_devices *windows_sorted_devices_array = NULL;
 uint32_t icd_count = 0;
 struct loader_icd_physical_devices *icd_phys_dev_array = NULL;
 uint32_t new_phys_devs_capacity = 0;
 uint32_t new_phys_devs_count = 0;
 struct loader_physical_device_term **new_phys_devs = NULL;

#if defined(_WIN32)
 // Get the physical devices supported by platform sorting mechanism into a separate list
 res = windows_read_sorted_physical_devices(inst, &windows_sorted_devices_count, &windows_sorted_devices_array);
 if (VK_SUCCESS != res) {
 goto out;
 }
#endif

 icd_count = inst->icd_terms_count;

 // Allocate something to store the physical device characteristics that we read from each ICD.
 icd_phys_dev_array =
 (struct loader_icd_physical_devices *)loader_stack_alloc(sizeof(struct loader_icd_physical_devices) * icd_count);
 if (NULL == icd_phys_dev_array) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Failed to allocate temporary ICD Physical device info array of size %d",
 icd_count);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 memset(icd_phys_dev_array, 0, sizeof(struct loader_icd_physical_devices) * icd_count);

 // For each ICD, query the number of physical devices, and then get an
 // internal value for those physical devices.
 icd_term = inst->icd_terms;
 uint32_t icd_idx = 0;
 while (NULL != icd_term) {
 res = icd_term->dispatch.EnumeratePhysicalDevices(icd_term->instance, &icd_phys_dev_array[icd_idx].device_count, NULL);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Call to \'vkEnumeratePhysicalDevices\' in ICD %s failed with error code "
 "VK_ERROR_OUT_OF_HOST_MEMORY",
 icd_term->scanned_icd->lib_name);
 goto out;
 } else if (VK_SUCCESS == res) {
 icd_phys_dev_array[icd_idx].physical_devices =
 (VkPhysicalDevice *)loader_stack_alloc(icd_phys_dev_array[icd_idx].device_count * sizeof(VkPhysicalDevice));
 if (NULL == icd_phys_dev_array[icd_idx].physical_devices) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Failed to allocate temporary ICD Physical device array for ICD %s of size %d",
 icd_term->scanned_icd->lib_name, icd_phys_dev_array[icd_idx].device_count);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 uint32_t allocated_count = icd_phys_dev_array[icd_idx].device_count;
 res = icd_term->dispatch.EnumeratePhysicalDevices(icd_term->instance, &(icd_phys_dev_array[icd_idx].device_count),
 icd_phys_dev_array[icd_idx].physical_devices);
 if (VK_ERROR_OUT_OF_HOST_MEMORY == res) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Call to \'vkEnumeratePhysicalDevices\' in ICD %s failed with error code "
 "VK_ERROR_OUT_OF_HOST_MEMORY",
 icd_term->scanned_icd->lib_name);
 goto out;
 }
 if (VK_SUCCESS != res) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Call to \'vkEnumeratePhysicalDevices\' in ICD %s failed with error code %d",
 icd_term->scanned_icd->lib_name, res);
 icd_phys_dev_array[icd_idx].device_count = 0;
 icd_phys_dev_array[icd_idx].physical_devices = 0;
 } else if (icd_phys_dev_array[icd_idx].device_count > allocated_count) {
 // The fill call sizes the array, but never read past what we actually allocated.
 icd_phys_dev_array[icd_idx].device_count = allocated_count;
 }
 } else {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Call to \'vkEnumeratePhysicalDevices\' in ICD %s failed with error code %d",
 icd_term->scanned_icd->lib_name, res);
 icd_phys_dev_array[icd_idx].device_count = 0;
 icd_phys_dev_array[icd_idx].physical_devices = 0;
 }
 icd_phys_dev_array[icd_idx].icd_term = icd_term;
 icd_term->physical_device_count = icd_phys_dev_array[icd_idx].device_count;
 icd_term = icd_term->next;
 ++icd_idx;
 }

 // Add up both the windows sorted and non windows found physical device counts
 for (uint32_t i = 0; i < windows_sorted_devices_count; ++i) {
 new_phys_devs_capacity += windows_sorted_devices_array[i].device_count;
 }
 for (uint32_t i = 0; i < icd_count; ++i) {
 new_phys_devs_capacity += icd_phys_dev_array[i].device_count;
 }

 // Bail out if there are no physical devices reported
 if (0 == new_phys_devs_capacity) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Failed to detect any valid GPUs in the current config");
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }

 // Create an allocation large enough to hold both the windows sorting enumeration and non-windows physical device
 // enumeration
 new_phys_devs = loader_instance_heap_calloc(inst, sizeof(struct loader_physical_device_term *) * new_phys_devs_capacity,
 VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_devs) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Failed to allocate new physical device array of size %d", new_phys_devs_capacity);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 // Copy over everything found through sorted enumeration
 for (uint32_t i = 0; i < windows_sorted_devices_count; ++i) {
 for (uint32_t j = 0; j < windows_sorted_devices_array[i].device_count; ++j) {
 res = check_and_add_to_new_phys_devs(inst, windows_sorted_devices_array[i].physical_devices[j],
 &windows_sorted_devices_array[i], &new_phys_devs_count, new_phys_devs);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }
 }

// Now go through the rest of the physical devices and add them to new_phys_devs
#if defined(LOADER_ENABLE_LINUX_SORT)

 if (is_linux_sort_enabled(inst)) {
 for (uint32_t dev = new_phys_devs_count; dev < new_phys_devs_capacity; ++dev) {
 new_phys_devs[dev] =
 loader_instance_heap_alloc(inst, sizeof(struct loader_physical_device_term), VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_devs[dev]) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "setup_loader_term_phys_devs: Failed to allocate physical device terminator object %d", dev);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 }

 // Get the physical devices supported by platform sorting mechanism into a separate list
 // Pass in a sublist to the function so it only operates on the correct elements. This means passing in a pointer to the
 // current next element in new_phys_devs and passing in a `count` of currently unwritten elements
 res = linux_read_sorted_physical_devices(inst, icd_count, icd_phys_dev_array, new_phys_devs_capacity - new_phys_devs_count,
 &new_phys_devs[new_phys_devs_count]);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 // Keep previously allocated physical device info since apps may already be using that!
 for (uint32_t new_idx = new_phys_devs_count; new_idx < new_phys_devs_capacity; new_idx++) {
 for (uint32_t old_idx = 0; old_idx < inst->phys_dev_count_term; old_idx++) {
 if (new_phys_devs[new_idx]->phys_dev == inst->phys_devs_term[old_idx]->phys_dev) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "Copying old device %u into new device %u", old_idx, new_idx);
 // Free the old new_phys_devs info since we're not using it before we assign the new info
 loader_instance_heap_free(inst, new_phys_devs[new_idx]);
 new_phys_devs[new_idx] = inst->phys_devs_term[old_idx];
 break;
 }
 }
 }
 // now set the count to the capacity, as now the list is filled in
 new_phys_devs_count = new_phys_devs_capacity;
 // We want the following code to run if either linux sorting is disabled at compile time or runtime
 } else {
#endif // LOADER_ENABLE_LINUX_SORT

 // Copy over everything found through the non-sorted means.
 for (uint32_t i = 0; i < icd_count; ++i) {
 for (uint32_t j = 0; j < icd_phys_dev_array[i].device_count; ++j) {
 res = check_and_add_to_new_phys_devs(inst, icd_phys_dev_array[i].physical_devices[j], &icd_phys_dev_array[i],
 &new_phys_devs_count, new_phys_devs);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 }
 }
#if defined(LOADER_ENABLE_LINUX_SORT)
 }
#endif // LOADER_ENABLE_LINUX_SORT
out:

 if (VK_SUCCESS != res) {
 if (NULL != new_phys_devs) {
 // We've encountered an error, so we should free the new buffers.
 for (uint32_t i = 0; i < new_phys_devs_capacity; i++) {
 // May not have allocated this far, skip it if we hadn't.
 if (new_phys_devs[i] == NULL) continue;

 // If an OOM occurred inside the copying of the new physical devices into the existing array
 // will leave some of the old physical devices in the array which may have been copied into
 // the new array, leading to them being freed twice. To avoid this we just make sure to not
 // delete physical devices which were copied.
 bool found = false;
 if (NULL != inst->phys_devs_term) {
 for (uint32_t old_idx = 0; old_idx < inst->phys_dev_count_term; old_idx++) {
 if (new_phys_devs[i] == inst->phys_devs_term[old_idx]) {
 found = true;
 break;
 }
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, new_phys_devs[i]);
 }
 }
 loader_instance_heap_free(inst, new_phys_devs);
 }
 inst->total_gpu_count = 0;
 } else {
 if (NULL != inst->phys_devs_term) {
 // Free everything in the old array that was not copied into the new array
 // here. We can't attempt to do that before here since the previous loop
 // looking before the "out:" label may hit an out of memory condition resulting
 // in memory leaking.
 for (uint32_t i = 0; i < inst->phys_dev_count_term; i++) {
 bool found = false;
 for (uint32_t j = 0; j < new_phys_devs_count; j++) {
 if (new_phys_devs != NULL && inst->phys_devs_term[i] == new_phys_devs[j]) {
 found = true;
 break;
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, inst->phys_devs_term[i]);
 }
 }
 loader_instance_heap_free(inst, inst->phys_devs_term);
 }

 // Swap out old and new devices list
 inst->phys_dev_count_term = new_phys_devs_count;
 inst->phys_devs_term = new_phys_devs;
 inst->total_gpu_count = new_phys_devs_count;
 }

 if (windows_sorted_devices_array != NULL) {
 for (uint32_t i = 0; i < windows_sorted_devices_count; ++i) {
 if (windows_sorted_devices_array[i].device_count > 0 && windows_sorted_devices_array[i].physical_devices != NULL) {
 loader_instance_heap_free(inst, windows_sorted_devices_array[i].physical_devices);
 }
 }
 loader_instance_heap_free(inst, windows_sorted_devices_array);
 }

 return res;
}
/**
 * Iterates through all drivers and unloads any which do not contain physical devices.
 * This saves address space, which for 32 bit applications is scarce.
 * This must only be called after a call to vkEnumeratePhysicalDevices that isn't just querying the count
 */
void unload_drivers_without_physical_devices(struct loader_instance *inst) {
 struct loader_icd_term *cur_icd_term = inst->icd_terms;
 struct loader_icd_term *prev_icd_term = NULL;

 while (NULL != cur_icd_term) {
 struct loader_icd_term *next_icd_term = cur_icd_term->next;
 if (cur_icd_term->physical_device_count == 0) {
 uint32_t cur_scanned_icd_index = UINT32_MAX;
 if (inst->icd_tramp_list.scanned_list) {
 for (uint32_t i = 0; i < inst->icd_tramp_list.count; i++) {
 if (&(inst->icd_tramp_list.scanned_list[i]) == cur_icd_term->scanned_icd) {
 cur_scanned_icd_index = i;
 break;
 }
 }
 }
 if (cur_scanned_icd_index != UINT32_MAX) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT | VULKAN_LOADER_DRIVER_BIT, 0,
 "Removing driver %s due to not having any physical devices", cur_icd_term->scanned_icd->lib_name);

 const VkAllocationCallbacks *allocation_callbacks = ignore_null_callback(&(inst->alloc_callbacks));
 if (cur_icd_term->instance) {
 loader_icd_close_objects(inst, cur_icd_term);
 cur_icd_term->dispatch.DestroyInstance(cur_icd_term->instance, allocation_callbacks);
 }
 cur_icd_term->instance = VK_NULL_HANDLE;
 loader_icd_destroy(inst, cur_icd_term, allocation_callbacks);
 cur_icd_term = NULL;
 struct loader_scanned_icd *scanned_icd_to_remove = &inst->icd_tramp_list.scanned_list[cur_scanned_icd_index];
 // Iterate through preloaded ICDs and remove the corresponding driver from that list
 loader_platform_thread_lock_mutex(&loader_preload_icd_lock);
 if (NULL != preloaded_icds.scanned_list) {
 for (uint32_t i = 0; i < preloaded_icds.count; i++) {
 if (NULL != preloaded_icds.scanned_list[i].lib_name && NULL != scanned_icd_to_remove->lib_name &&
 strcmp(preloaded_icds.scanned_list[i].lib_name, scanned_icd_to_remove->lib_name) == 0) {
 loader_unload_scanned_icd(NULL, &preloaded_icds.scanned_list[i]);
 // condense the list so that it doesn't contain empty elements.
 if (i < preloaded_icds.count - 1) {
 memcpy((void *)&preloaded_icds.scanned_list[i],
 (void *)&preloaded_icds.scanned_list[preloaded_icds.count - 1],
 sizeof(struct loader_scanned_icd));
 memset((void *)&preloaded_icds.scanned_list[preloaded_icds.count - 1], 0,
 sizeof(struct loader_scanned_icd));
 }
 if (i > 0) {
 preloaded_icds.count--;
 }

 break;
 }
 }
 }
 loader_platform_thread_unlock_mutex(&loader_preload_icd_lock);

 loader_unload_scanned_icd(inst, scanned_icd_to_remove);
 }

 if (NULL == prev_icd_term) {
 inst->icd_terms = next_icd_term;
 } else {
 prev_icd_term->next = next_icd_term;
 }
 } else {
 prev_icd_term = cur_icd_term;
 }
 cur_icd_term = next_icd_term;
 }
}

VkResult setup_loader_tramp_phys_dev_groups(struct loader_instance *inst, uint32_t group_count,
 VkPhysicalDeviceGroupProperties *groups) {
 VkResult res = VK_SUCCESS;
 uint32_t cur_idx;
 uint32_t dev_idx;

 if (0 == group_count) {
 return VK_SUCCESS;
 }

 // Generate a list of all the devices and convert them to the loader ID
 uint32_t phys_dev_count = 0;
 for (cur_idx = 0; cur_idx < group_count; ++cur_idx) {
 phys_dev_count += groups[cur_idx].physicalDeviceCount;
 }
 VkPhysicalDevice *devices = (VkPhysicalDevice *)loader_stack_alloc(sizeof(VkPhysicalDevice) * phys_dev_count);
 if (NULL == devices) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 uint32_t cur_device = 0;
 for (cur_idx = 0; cur_idx < group_count; ++cur_idx) {
 for (dev_idx = 0; dev_idx < groups[cur_idx].physicalDeviceCount; ++dev_idx) {
 devices[cur_device++] = groups[cur_idx].physicalDevices[dev_idx];
 }
 }

 // Update the devices based on the loader physical device values.
 res = setup_loader_tramp_phys_devs(inst, phys_dev_count, devices);
 if (VK_SUCCESS != res) {
 return res;
 }

 // Update the devices in the group structures now
 cur_device = 0;
 for (cur_idx = 0; cur_idx < group_count; ++cur_idx) {
 for (dev_idx = 0; dev_idx < groups[cur_idx].physicalDeviceCount; ++dev_idx) {
 groups[cur_idx].physicalDevices[dev_idx] = devices[cur_device++];
 }
 }

 return res;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumeratePhysicalDevices(VkInstance instance, uint32_t *pPhysicalDeviceCount,
 VkPhysicalDevice *pPhysicalDevices) {
 struct loader_instance *inst = (struct loader_instance *)instance;
 VkResult res = VK_SUCCESS;

 // Always call the setup loader terminator physical devices because they may
 // have changed at any point.
 res = setup_loader_term_phys_devs(inst);
 if (VK_SUCCESS != res) {
 goto out;
 }

 if (inst->settings.settings_active && inst->settings.device_configurations_active) {
 // Use settings file device_configurations if present
 if (NULL == pPhysicalDevices) {
 // take the minimum of the settings configurations count and number of terminators
 *pPhysicalDeviceCount = (inst->settings.device_configuration_count < inst->phys_dev_count_term)
 ? inst->settings.device_configuration_count
 : inst->phys_dev_count_term;
 } else {
 res = loader_apply_settings_device_configurations(inst, pPhysicalDeviceCount, pPhysicalDevices);
 }
 } else {
 // Otherwise just copy the physical devices up normally and pass it up the chain
 uint32_t copy_count = inst->phys_dev_count_term;
 if (NULL != pPhysicalDevices) {
 if (copy_count > *pPhysicalDeviceCount) {
 copy_count = *pPhysicalDeviceCount;
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "terminator_EnumeratePhysicalDevices : Trimming device count from %d to %d.", inst->phys_dev_count_term,
 copy_count);
 res = VK_INCOMPLETE;
 }

 for (uint32_t i = 0; i < copy_count; i++) {
 pPhysicalDevices[i] = (VkPhysicalDevice)inst->phys_devs_term[i];
 }
 }

 *pPhysicalDeviceCount = copy_count;
 }

out:

 return res;
}

VkResult check_physical_device_extensions_for_driver_properties_extension(struct loader_physical_device_term *phys_dev_term,
 bool *supports_driver_properties) {
 *supports_driver_properties = false;
 uint32_t extension_count = 0;
 VkResult res = phys_dev_term->this_icd_term->dispatch.EnumerateDeviceExtensionProperties(phys_dev_term->phys_dev, NULL,
 &extension_count, NULL);
 if (res != VK_SUCCESS || extension_count == 0) {
 return VK_SUCCESS;
 }
 VkExtensionProperties *extension_data = loader_stack_alloc(sizeof(VkExtensionProperties) * extension_count);
 if (NULL == extension_data) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }

 uint32_t allocated_count = extension_count;
 res = phys_dev_term->this_icd_term->dispatch.EnumerateDeviceExtensionProperties(phys_dev_term->phys_dev, NULL, &extension_count,
 extension_data);
 if (res != VK_SUCCESS) {
 return VK_SUCCESS;
 }
 // The count returned by the second call sizes the array, but never read past what we actually allocated.
 for (uint32_t j = 0; j < extension_count && j < allocated_count; j++) {
 if (!strcmp(extension_data[j].extensionName, VK_KHR_DRIVER_PROPERTIES_EXTENSION_NAME)) {
 *supports_driver_properties = true;
 return VK_SUCCESS;
 }
 }
 return VK_SUCCESS;
}

// Helper struct containing the relevant details of a VkPhysicalDevice necessary for applying the loader settings device
// configurations.
typedef struct physical_device_configuration_details {
 bool pd_was_added;
 bool pd_supports_vulkan_11;
 bool pd_supports_driver_properties;
 VkPhysicalDeviceProperties properties;
 VkPhysicalDeviceIDProperties device_id_properties;
 VkPhysicalDeviceDriverProperties driver_properties;

} physical_device_configuration_details;

// Apply the device_configurations in the settings file to the output VkPhysicalDeviceList.
// That means looking up each VkPhysicalDevice's deviceUUID, filtering using that, and putting them in the order of
// device_configurations in the settings file.
VkResult loader_apply_settings_device_configurations(struct loader_instance *inst, uint32_t *pPhysicalDeviceCount,
 VkPhysicalDevice *pPhysicalDevices) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "Reordering the output of vkEnumeratePhysicalDevices to match the loader settings device configurations list");

 physical_device_configuration_details *pd_details =
 loader_stack_alloc(inst->phys_dev_count_term * sizeof(physical_device_configuration_details));
 if (NULL == pd_details) {
 return VK_ERROR_OUT_OF_HOST_MEMORY;
 }
 memset(pd_details, 0, inst->phys_dev_count_term * sizeof(physical_device_configuration_details));

 for (uint32_t i = 0; i < inst->phys_dev_count_term; i++) {
 struct loader_physical_device_term *phys_dev_term = inst->phys_devs_term[i];

 phys_dev_term->this_icd_term->dispatch.GetPhysicalDeviceProperties(phys_dev_term->phys_dev, &pd_details[i].properties);
 if (pd_details[i].properties.apiVersion < VK_API_VERSION_1_1) {
 // Device isn't eligible for sorting
 continue;
 }
 pd_details[i].pd_supports_vulkan_11 = true;
 if (pd_details[i].properties.apiVersion >= VK_API_VERSION_1_2) {
 pd_details[i].pd_supports_driver_properties = true;
 }

 // If this physical device isn't 1.2, then we need to check if it supports VK_KHR_driver_properties
 if (!pd_details[i].pd_supports_driver_properties) {
 VkResult res = check_physical_device_extensions_for_driver_properties_extension(
 phys_dev_term, &pd_details[i].pd_supports_driver_properties);
 if (res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 return res;
 }
 }

 pd_details[i].device_id_properties.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ID_PROPERTIES;
 pd_details[i].driver_properties.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES;
 if (pd_details[i].pd_supports_driver_properties) {
 pd_details[i].device_id_properties.pNext = (void *)&pd_details[i].driver_properties;
 }

 VkPhysicalDeviceProperties2 props2 = {0};
 props2.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2;
 props2.pNext = (void *)&pd_details[i].device_id_properties;
 if (phys_dev_term->this_icd_term->dispatch.GetPhysicalDeviceProperties2) {
 phys_dev_term->this_icd_term->dispatch.GetPhysicalDeviceProperties2(phys_dev_term->phys_dev, &props2);
 }
 }

 // Loop over the setting's device configurations, find each VkPhysicalDevice which matches the deviceUUID given, add to the
 // pPhysicalDevices output list.
 uint32_t written_output_index = 0;

 for (uint32_t i = 0; i < inst->settings.device_configuration_count; i++) {
 uint8_t *current_deviceUUID = inst->settings.device_configurations[i].deviceUUID;
 uint8_t *current_driverUUID = inst->settings.device_configurations[i].driverUUID;
 bool configuration_found = false;
 for (uint32_t j = 0; j < inst->phys_dev_count_term; j++) {
 // Don't compare deviceUUID's if they have nothing, since we require deviceUUID's to effectively sort them.
 if (!pd_details[j].pd_supports_vulkan_11) {
 continue;
 }
 if (memcmp(current_deviceUUID, pd_details[j].device_id_properties.deviceUUID, sizeof(uint8_t) * VK_UUID_SIZE) == 0 &&
 memcmp(current_driverUUID, pd_details[j].device_id_properties.driverUUID, sizeof(uint8_t) * VK_UUID_SIZE) == 0 &&
 inst->settings.device_configurations[i].driverVersion == pd_details[j].properties.driverVersion) {
 configuration_found = true;
 // Catch when there are more device_configurations than space available in the output
 if (written_output_index >= *pPhysicalDeviceCount) {
 *pPhysicalDeviceCount = written_output_index; // write out how many were written
 return VK_INCOMPLETE;
 }
 if (pd_details[j].pd_supports_driver_properties) {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "pPhysicalDevices array index %d is set to \"%s\" (%s, version %d) ", written_output_index,
 pd_details[j].properties.deviceName, pd_details[j].driver_properties.driverName,
 pd_details[j].properties.driverVersion);
 } else {
 loader_log(inst, VULKAN_LOADER_DEBUG_BIT, 0,
 "pPhysicalDevices array index %d is set to \"%s\" (driver version %d) ", written_output_index,
 pd_details[j].properties.deviceName, pd_details[j].properties.driverVersion);
 }
 pPhysicalDevices[written_output_index++] = (VkPhysicalDevice)inst->phys_devs_term[j];
 pd_details[j].pd_was_added = true;
 break;
 }
 }
 if (!configuration_found) {
 char device_uuid_str[UUID_STR_LEN] = {0};
 loader_log_generate_uuid_string(current_deviceUUID, device_uuid_str);
 char driver_uuid_str[UUID_STR_LEN] = {0};
 loader_log_generate_uuid_string(current_driverUUID, driver_uuid_str);

 // Log that this configuration was missing.
 if (inst->settings.device_configurations[i].deviceName[0] != '\0' &&
 inst->settings.device_configurations[i].driverName[0] != '\0') {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_apply_settings_device_configurations: settings file contained device_configuration which does not "
 "appear in the enumerated VkPhysicalDevices. Missing VkPhysicalDevice with deviceName: \"%s\", "
 "deviceUUID: %s, driverName: %s, driverUUID: %s, driverVersion: %d",
 inst->settings.device_configurations[i].deviceName, device_uuid_str,
 inst->settings.device_configurations[i].driverName, driver_uuid_str,
 inst->settings.device_configurations[i].driverVersion);
 } else if (inst->settings.device_configurations[i].deviceName[0] != '\0') {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_apply_settings_device_configurations: settings file contained device_configuration which does not "
 "appear in the enumerated VkPhysicalDevices. Missing VkPhysicalDevice with deviceName: \"%s\", "
 "deviceUUID: %s, driverUUID: %s, driverVersion: %d",
 inst->settings.device_configurations[i].deviceName, device_uuid_str, driver_uuid_str,
 inst->settings.device_configurations[i].driverVersion);
 } else {
 loader_log(
 inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_apply_settings_device_configurations: settings file contained device_configuration which does not "
 "appear in the enumerated VkPhysicalDevices. Missing VkPhysicalDevice with deviceUUID: "
 "%s, driverUUID: %s, driverVersion: %d",
 device_uuid_str, driver_uuid_str, inst->settings.device_configurations[i].driverVersion);
 }
 }
 }

 for (uint32_t j = 0; j < inst->phys_dev_count_term; j++) {
 if (!pd_details[j].pd_was_added) {
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "VkPhysicalDevice \"%s\" did not appear in the settings file device configurations list, so was not added "
 "to the pPhysicalDevices array",
 pd_details[j].properties.deviceName);
 }
 }

 if (written_output_index == 0) {
 loader_log(inst, VULKAN_LOADER_WARN_BIT, 0,
 "loader_apply_settings_device_configurations: None of the settings file device configurations had "
 "deviceUUID's that corresponded to enumerated VkPhysicalDevices. Returning VK_ERROR_INITIALIZATION_FAILED");
 return VK_ERROR_INITIALIZATION_FAILED;
 }

 *pPhysicalDeviceCount = written_output_index; // update with how many were written
 return VK_SUCCESS;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumerateDeviceExtensionProperties(VkPhysicalDevice physicalDevice,
 const char *pLayerName, uint32_t *pPropertyCount,
 VkExtensionProperties *pProperties) {
 if (NULL == pPropertyCount) {
 return VK_INCOMPLETE;
 }

 struct loader_physical_device_term *phys_dev_term;

 // Any layer or trampoline wrapping should be removed at this point in time can just cast to the expected
 // type for VkPhysicalDevice.
 phys_dev_term = (struct loader_physical_device_term *)physicalDevice;

 // if we got here with a non-empty pLayerName, look up the extensions
 // from the json
 if (pLayerName != NULL && strlen(pLayerName) > 0) {
 uint32_t count;
 uint32_t copy_size;
 const struct loader_instance *inst = phys_dev_term->this_icd_term->this_instance;
 struct loader_device_extension_list *dev_ext_list = NULL;
 struct loader_device_extension_list local_ext_list;
 memset(&local_ext_list, 0, sizeof(local_ext_list));
 if (vk_string_validate(MaxLoaderStringLength, pLayerName) == VK_STRING_ERROR_NONE) {
 for (uint32_t i = 0; i < inst->instance_layer_list.count; i++) {
 struct loader_layer_properties *props = &inst->instance_layer_list.list[i];
 if (strcmp(props->info.layerName, pLayerName) == 0) {
 dev_ext_list = &props->device_extension_list;
 }
 }

 count = (dev_ext_list == NULL) ? 0 : dev_ext_list->count;
 if (pProperties == NULL) {
 *pPropertyCount = count;
 loader_destroy_generic_list(inst, (struct loader_generic_list *)&local_ext_list);
 return VK_SUCCESS;
 }

 copy_size = *pPropertyCount < count ? *pPropertyCount : count;
 for (uint32_t i = 0; i < copy_size; i++) {
 memcpy(&pProperties[i], &dev_ext_list->list[i].props, sizeof(VkExtensionProperties));
 }
 *pPropertyCount = copy_size;

 loader_destroy_generic_list(inst, (struct loader_generic_list *)&local_ext_list);
 if (copy_size < count) {
 return VK_INCOMPLETE;
 }
 } else {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "vkEnumerateDeviceExtensionProperties: pLayerName is too long or is badly formed");
 return VK_ERROR_EXTENSION_NOT_PRESENT;
 }

 return VK_SUCCESS;
 }

 // user is querying driver extensions and has supplied their own storage - just fill it out
 else if (pProperties) {
 struct loader_icd_term *icd_term = phys_dev_term->this_icd_term;
 uint32_t written_count = *pPropertyCount;
 VkResult res =
 icd_term->dispatch.EnumerateDeviceExtensionProperties(phys_dev_term->phys_dev, NULL, &written_count, pProperties);
 if (res != VK_SUCCESS) {
 return res;
 }

 // Iterate over active layers, if they are an implicit layer, add their device extensions
 // After calling into the driver, written_count contains the amount of device extensions written. We can therefore write
 // layer extensions starting at that point in pProperties
 for (uint32_t i = 0; i < icd_term->this_instance->expanded_activated_layer_list.count; i++) {
 struct loader_layer_properties *layer_props = icd_term->this_instance->expanded_activated_layer_list.list[i];
 if (0 == (layer_props->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER)) {
 struct loader_device_extension_list *layer_ext_list = &layer_props->device_extension_list;
 for (uint32_t j = 0; j < layer_ext_list->count; j++) {
 struct loader_dev_ext_props *cur_ext_props = &layer_ext_list->list[j];
 // look for duplicates
 if (has_vk_extension_property_array(&cur_ext_props->props, written_count, pProperties)) {
 continue;
 }

 if (*pPropertyCount <= written_count) {
 return VK_INCOMPLETE;
 }

 memcpy(&pProperties[written_count], &cur_ext_props->props, sizeof(VkExtensionProperties));
 written_count++;
 }
 }
 }
 // Make sure we update the pPropertyCount with the how many were written
 *pPropertyCount = written_count;
 return res;
 }
 // Use `goto out;` for rest of this function

 // This case is during the call down the instance chain with pLayerName == NULL and pProperties == NULL
 struct loader_icd_term *icd_term = phys_dev_term->this_icd_term;
 struct loader_extension_list all_exts = {0};
 VkResult res;

 // We need to find the count without duplicates. This requires querying the driver for the names of the extensions.
 res = icd_term->dispatch.EnumerateDeviceExtensionProperties(phys_dev_term->phys_dev, NULL, &all_exts.count, NULL);
 if (res != VK_SUCCESS) {
 goto out;
 }
 // Then allocate memory to store the physical device extension list + the extensions layers provide
 // all_exts.count currently is the number of driver extensions
 all_exts.capacity = sizeof(VkExtensionProperties) * (all_exts.count + 20);
 all_exts.list = loader_instance_heap_alloc(icd_term->this_instance, all_exts.capacity, VK_SYSTEM_ALLOCATION_SCOPE_COMMAND);
 if (NULL == all_exts.list) {
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 // Get the available device extensions and put them in all_exts.list
 res = icd_term->dispatch.EnumerateDeviceExtensionProperties(phys_dev_term->phys_dev, NULL, &all_exts.count, all_exts.list);
 if (res != VK_SUCCESS) {
 goto out;
 }

 // Iterate over active layers, if they are an implicit layer, add their device extensions to all_exts.list
 for (uint32_t i = 0; i < icd_term->this_instance->expanded_activated_layer_list.count; i++) {
 struct loader_layer_properties *layer_props = icd_term->this_instance->expanded_activated_layer_list.list[i];
 if (0 == (layer_props->type_flags & VK_LAYER_TYPE_FLAG_EXPLICIT_LAYER)) {
 struct loader_device_extension_list *layer_ext_list = &layer_props->device_extension_list;
 for (uint32_t j = 0; j < layer_ext_list->count; j++) {
 res = loader_add_to_ext_list(icd_term->this_instance, &all_exts, 1, &layer_ext_list->list[j].props);
 if (res != VK_SUCCESS) {
 goto out;
 }
 }
 }
 }

 // Write out the final de-duplicated count to pPropertyCount
 *pPropertyCount = all_exts.count;
 res = VK_SUCCESS;

out:

 loader_destroy_generic_list(icd_term->this_instance, (struct loader_generic_list *)&all_exts);
 return res;
}

TEST_FUNCTION_EXPORT VkStringErrorFlags vk_string_validate(const int max_length, const char *utf8) {
 VkStringErrorFlags result = VK_STRING_ERROR_NONE;
 int num_char_bytes = 0;
 int i, j;

 if (utf8 == NULL) {
 return VK_STRING_ERROR_NULL_PTR;
 }

 for (i = 0; i <= max_length; i++) {
 if (utf8[i] == 0) {
 break;
 } else if (i == max_length) {
 result |= VK_STRING_ERROR_LENGTH;
 break;
 } else if ((utf8[i] >= 0x20) && (utf8[i] < 0x7f)) {
 num_char_bytes = 0;
 } else if ((utf8[i] & UTF8_ONE_BYTE_MASK) == UTF8_ONE_BYTE_CODE) {
 num_char_bytes = 1;
 } else if ((utf8[i] & UTF8_TWO_BYTE_MASK) == UTF8_TWO_BYTE_CODE) {
 num_char_bytes = 2;
 } else if ((utf8[i] & UTF8_THREE_BYTE_MASK) == UTF8_THREE_BYTE_CODE) {
 num_char_bytes = 3;
 } else {
 result = VK_STRING_ERROR_BAD_DATA;
 }

 // Validate the following num_char_bytes of data
 for (j = 0; (j < num_char_bytes) && (i < max_length); j++) {
 if (++i == max_length) {
 result |= VK_STRING_ERROR_LENGTH;
 break;
 }
 if (utf8[i] == 0) {
 // The string terminated in the middle of a multi-byte character. Stop here so the
 // continuation-byte scan doesn't read past the terminator.
 result |= VK_STRING_ERROR_BAD_DATA;
 return result;
 }
 if ((utf8[i] & UTF8_DATA_BYTE_MASK) != UTF8_DATA_BYTE_CODE) {
 result |= VK_STRING_ERROR_BAD_DATA;
 }
 }
 }
 return result;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumerateInstanceVersion(uint32_t *pApiVersion) {
 // NOTE: The Vulkan WG doesn't want us checking pApiVersion for NULL, but instead
 // prefers us crashing.
 *pApiVersion = VK_HEADER_VERSION_COMPLETE;
 return VK_SUCCESS;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_pre_instance_EnumerateInstanceVersion(const VkEnumerateInstanceVersionChain *chain,
 uint32_t *pApiVersion) {
 (void)chain;
 return terminator_EnumerateInstanceVersion(pApiVersion);
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumerateInstanceExtensionProperties(const char *pLayerName, uint32_t *pPropertyCount,
 VkExtensionProperties *pProperties) {
 struct loader_extension_list *global_ext_list = NULL;
 struct loader_layer_list instance_layers;
 struct loader_extension_list local_ext_list;
 struct loader_icd_tramp_list icd_tramp_list;
 uint32_t copy_size;
 VkResult res = VK_SUCCESS;
 struct loader_envvar_all_filters layer_filters = {0};

 memset(&local_ext_list, 0, sizeof(local_ext_list));
 memset(&instance_layers, 0, sizeof(instance_layers));
 memset(&icd_tramp_list, 0, sizeof(icd_tramp_list));

 res = parse_layer_environment_var_filters(NULL, &layer_filters);
 if (VK_SUCCESS != res) {
 goto out;
 }

 // Get layer libraries if needed
 if (pLayerName && strlen(pLayerName) != 0) {
 if (vk_string_validate(MaxLoaderStringLength, pLayerName) != VK_STRING_ERROR_NONE) {
 assert(VK_FALSE && "vkEnumerateInstanceExtensionProperties: pLayerName is too long or is badly formed");
 res = VK_ERROR_EXTENSION_NOT_PRESENT;
 goto out;
 }

 res = loader_scan_for_layers(NULL, &instance_layers, &layer_filters);
 if (VK_SUCCESS != res) {
 goto out;
 }
 for (uint32_t i = 0; i < instance_layers.count; i++) {
 struct loader_layer_properties *props = &instance_layers.list[i];
 if (strcmp(props->info.layerName, pLayerName) == 0) {
 global_ext_list = &props->instance_extension_list;
 break;
 }
 }
 } else {
 // Preload ICD libraries so subsequent calls to EnumerateInstanceExtensionProperties don't have to load them
 loader_preload_icds();

 // Scan/discover all ICD libraries
 res = loader_icd_scan(NULL, &icd_tramp_list, NULL, NULL);
 // EnumerateInstanceExtensionProperties can't return anything other than OOM or VK_ERROR_LAYER_NOT_PRESENT
 if ((VK_SUCCESS != res && icd_tramp_list.count > 0) || res == VK_ERROR_OUT_OF_HOST_MEMORY) {
 goto out;
 }
 // Get extensions from all ICD's, merge so no duplicates
 res = loader_get_icd_loader_instance_extensions(NULL, &icd_tramp_list, &local_ext_list);
 if (VK_SUCCESS != res) {
 goto out;
 }
 loader_clear_scanned_icd_list(NULL, &icd_tramp_list);

 // Append enabled implicit layers.
 res = loader_scan_for_implicit_layers(NULL, &instance_layers, &layer_filters);
 if (VK_SUCCESS != res) {
 goto out;
 }
 for (uint32_t i = 0; i < instance_layers.count; i++) {
 struct loader_extension_list *ext_list = &instance_layers.list[i].instance_extension_list;
 res = loader_add_to_ext_list(NULL, &local_ext_list, ext_list->count, ext_list->list);
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 global_ext_list = &local_ext_list;
 }

 if (global_ext_list == NULL) {
 res = VK_ERROR_LAYER_NOT_PRESENT;
 goto out;
 }

 if (pProperties == NULL) {
 *pPropertyCount = global_ext_list->count;
 goto out;
 }

 copy_size = *pPropertyCount < global_ext_list->count ? *pPropertyCount : global_ext_list->count;
 for (uint32_t i = 0; i < copy_size; i++) {
 memcpy(&pProperties[i], &global_ext_list->list[i], sizeof(VkExtensionProperties));
 }
 *pPropertyCount = copy_size;

 if (copy_size < global_ext_list->count) {
 res = VK_INCOMPLETE;
 goto out;
 }

out:
 loader_destroy_generic_list(NULL, (struct loader_generic_list *)&icd_tramp_list);
 loader_destroy_generic_list(NULL, (struct loader_generic_list *)&local_ext_list);
 loader_delete_layer_list_and_properties(NULL, &instance_layers);
 return res;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_pre_instance_EnumerateInstanceExtensionProperties(
 const VkEnumerateInstanceExtensionPropertiesChain *chain, const char *pLayerName, uint32_t *pPropertyCount,
 VkExtensionProperties *pProperties) {
 (void)chain;
 return terminator_EnumerateInstanceExtensionProperties(pLayerName, pPropertyCount, pProperties);
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumerateInstanceLayerProperties(uint32_t *pPropertyCount,
 VkLayerProperties *pProperties) {
 VkResult result = VK_SUCCESS;
 struct loader_layer_list instance_layer_list = {0};
 struct loader_envvar_all_filters layer_filters = {0};

 LOADER_PLATFORM_THREAD_ONCE(&once_init, loader_initialize);

 result = parse_layer_environment_var_filters(NULL, &layer_filters);
 if (VK_SUCCESS != result) {
 goto out;
 }

 // Get layer libraries
 result = loader_scan_for_layers(NULL, &instance_layer_list, &layer_filters);
 if (VK_SUCCESS != result) {
 goto out;
 }

 uint32_t layers_to_write_out = 0;
 for (uint32_t i = 0; i < instance_layer_list.count; i++) {
 if (instance_layer_list.list[i].settings_control_value == LOADER_SETTINGS_LAYER_CONTROL_ON ||
 instance_layer_list.list[i].settings_control_value == LOADER_SETTINGS_LAYER_CONTROL_DEFAULT) {
 layers_to_write_out++;
 }
 }

 if (pProperties == NULL) {
 *pPropertyCount = layers_to_write_out;
 goto out;
 }

 uint32_t output_properties_index = 0;
 for (uint32_t i = 0; i < instance_layer_list.count; i++) {
 if (output_properties_index < *pPropertyCount &&
 (instance_layer_list.list[i].settings_control_value == LOADER_SETTINGS_LAYER_CONTROL_ON ||
 instance_layer_list.list[i].settings_control_value == LOADER_SETTINGS_LAYER_CONTROL_DEFAULT)) {
 memcpy(&pProperties[output_properties_index], &instance_layer_list.list[i].info, sizeof(VkLayerProperties));
 output_properties_index++;
 }
 }
 if (output_properties_index < layers_to_write_out) {
 // Indicates that we had more elements to write but ran out of room
 result = VK_INCOMPLETE;
 }

 *pPropertyCount = output_properties_index;

out:

 loader_delete_layer_list_and_properties(NULL, &instance_layer_list);
 return result;
}

VKAPI_ATTR VkResult VKAPI_CALL terminator_pre_instance_EnumerateInstanceLayerProperties(
 const VkEnumerateInstanceLayerPropertiesChain *chain, uint32_t *pPropertyCount, VkLayerProperties *pProperties) {
 (void)chain;
 return terminator_EnumerateInstanceLayerProperties(pPropertyCount, pProperties);
}

// ---- Vulkan Core 1.1 terminators

VKAPI_ATTR VkResult VKAPI_CALL terminator_EnumeratePhysicalDeviceGroups(
 VkInstance instance, uint32_t *pPhysicalDeviceGroupCount, VkPhysicalDeviceGroupProperties *pPhysicalDeviceGroupProperties) {
 struct loader_instance *inst = (struct loader_instance *)instance;

 VkResult res = VK_SUCCESS;
 struct loader_icd_term *icd_term;
 uint32_t total_count = 0;
 uint32_t cur_icd_group_count = 0;
 VkPhysicalDeviceGroupProperties **new_phys_dev_groups = NULL;
 struct loader_physical_device_group_term *local_phys_dev_groups = NULL;
 PFN_vkEnumeratePhysicalDeviceGroups fpEnumeratePhysicalDeviceGroups = NULL;
 struct loader_icd_physical_devices *sorted_phys_dev_array = NULL;
 uint32_t sorted_count = 0;

 // For each ICD, query the number of physical device groups, and then get an
 // internal value for those physical devices.
 icd_term = inst->icd_terms;
 while (NULL != icd_term) {
 cur_icd_group_count = 0;

 // Get the function pointer to use to call into the ICD. This could be the core or KHR version
 if (inst->enabled_extensions.khr_device_group_creation) {
 fpEnumeratePhysicalDeviceGroups = icd_term->dispatch.EnumeratePhysicalDeviceGroupsKHR;
 } else {
 fpEnumeratePhysicalDeviceGroups = icd_term->dispatch.EnumeratePhysicalDeviceGroups;
 }

 if (NULL == fpEnumeratePhysicalDeviceGroups) {
 // Treat each ICD's GPU as it's own group if the extension isn't supported
 res = icd_term->dispatch.EnumeratePhysicalDevices(icd_term->instance, &cur_icd_group_count, NULL);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of \'EnumeratePhysicalDevices\' "
 "to ICD %s to get plain phys dev count.",
 icd_term->scanned_icd->lib_name);
 continue;
 }
 } else {
 // Query the actual group info
 res = fpEnumeratePhysicalDeviceGroups(icd_term->instance, &cur_icd_group_count, NULL);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDeviceGroups\' to ICD %s to get count.",
 icd_term->scanned_icd->lib_name);
 continue;
 }
 }
 total_count += cur_icd_group_count;
 icd_term = icd_term->next;
 }

 // If GPUs not sorted yet, look through them and generate list of all available GPUs
 if (0 == total_count || 0 == inst->total_gpu_count) {
 res = setup_loader_term_phys_devs(inst);
 if (VK_SUCCESS != res) {
 goto out;
 }
 }

 if (NULL != pPhysicalDeviceGroupProperties) {
 // Create an array for the new physical device groups, which will be stored
 // in the instance for the Terminator code.
 new_phys_dev_groups = (VkPhysicalDeviceGroupProperties **)loader_instance_heap_calloc(
 inst, total_count * sizeof(VkPhysicalDeviceGroupProperties *), VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_dev_groups) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed to allocate new physical device group array of size %d",
 total_count);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 // Create a temporary array (on the stack) to keep track of the
 // returned VkPhysicalDevice values.
 local_phys_dev_groups = loader_stack_alloc(sizeof(struct loader_physical_device_group_term) * total_count);
 // Initialize the memory to something valid
 memset(local_phys_dev_groups, 0, sizeof(struct loader_physical_device_group_term) * total_count);

#if defined(_WIN32)
 // Get the physical devices supported by platform sorting mechanism into a separate list
 res = windows_read_sorted_physical_devices(inst, &sorted_count, &sorted_phys_dev_array);
 if (VK_SUCCESS != res) {
 goto out;
 }
#endif

 cur_icd_group_count = 0;
 icd_term = inst->icd_terms;
 while (NULL != icd_term) {
 uint32_t count_this_time = total_count - cur_icd_group_count;

 // Get the function pointer to use to call into the ICD. This could be the core or KHR version
 if (inst->enabled_extensions.khr_device_group_creation) {
 fpEnumeratePhysicalDeviceGroups = icd_term->dispatch.EnumeratePhysicalDeviceGroupsKHR;
 } else {
 fpEnumeratePhysicalDeviceGroups = icd_term->dispatch.EnumeratePhysicalDeviceGroups;
 }

 if (NULL == fpEnumeratePhysicalDeviceGroups) {
 icd_term->dispatch.EnumeratePhysicalDevices(icd_term->instance, &count_this_time, NULL);

 // The driver can report more devices on this query than it did during the counting pass above. The local arrays
 // were sized to total_count, so never let this ICD write past the space still reserved for it.
 if (count_this_time > total_count - cur_icd_group_count) {
 count_this_time = total_count - cur_icd_group_count;
 }

 VkPhysicalDevice *phys_dev_array = loader_stack_alloc(sizeof(VkPhysicalDevice) * count_this_time);
 if (NULL == phys_dev_array) {
 loader_log(
 inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed to allocate local physical device array of size %d",
 count_this_time);
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }

 res = icd_term->dispatch.EnumeratePhysicalDevices(icd_term->instance, &count_this_time, phys_dev_array);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDevices\' to ICD %s to get plain phys dev count.",
 icd_term->scanned_icd->lib_name);
 goto out;
 }

 // Add each GPU as it's own group
 for (uint32_t indiv_gpu = 0; indiv_gpu < count_this_time; indiv_gpu++) {
 uint32_t cur_index = indiv_gpu + cur_icd_group_count;
 local_phys_dev_groups[cur_index].this_icd_term = icd_term;
 local_phys_dev_groups[cur_index].group_props.physicalDeviceCount = 1;
 local_phys_dev_groups[cur_index].group_props.physicalDevices[0] = phys_dev_array[indiv_gpu];
 }

 } else {
 res = fpEnumeratePhysicalDeviceGroups(icd_term->instance, &count_this_time, NULL);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDeviceGroups\' to ICD %s to get group count.",
 icd_term->scanned_icd->lib_name);
 goto out;
 }
 // Same guard as the plain-device path: the re-queried count can exceed the space sized during the counting pass.
 if (count_this_time > total_count - cur_icd_group_count) {
 count_this_time = total_count - cur_icd_group_count;
 }
 if (cur_icd_group_count + count_this_time < *pPhysicalDeviceGroupCount) {
 // The total amount is still less than the amount of physical device group data passed in
 // by the callee. Therefore, we don't have to allocate any temporary structures and we
 // can just use the data that was passed in.
 res = fpEnumeratePhysicalDeviceGroups(icd_term->instance, &count_this_time,
 &pPhysicalDeviceGroupProperties[cur_icd_group_count]);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDeviceGroups\' to ICD %s to get group information.",
 icd_term->scanned_icd->lib_name);
 goto out;
 }
 for (uint32_t group = 0; group < count_this_time; ++group) {
 uint32_t cur_index = group + cur_icd_group_count;
 local_phys_dev_groups[cur_index].group_props = pPhysicalDeviceGroupProperties[cur_index];
 // physicalDevices is a fixed VK_MAX_DEVICE_GROUP_SIZE array; don't trust a larger count from the ICD.
 if (local_phys_dev_groups[cur_index].group_props.physicalDeviceCount > VK_MAX_DEVICE_GROUP_SIZE) {
 local_phys_dev_groups[cur_index].group_props.physicalDeviceCount = VK_MAX_DEVICE_GROUP_SIZE;
 }
 local_phys_dev_groups[cur_index].this_icd_term = icd_term;
 }
 } else {
 // There's not enough space in the callee's allocated pPhysicalDeviceGroupProperties structs,
 // so we have to allocate temporary versions to collect all the data. However, we need to make
 // sure that at least the ones we do query utilize any pNext data in the callee's version.
 VkPhysicalDeviceGroupProperties *tmp_group_props =
 loader_stack_alloc(count_this_time * sizeof(VkPhysicalDeviceGroupProperties));
 for (uint32_t group = 0; group < count_this_time; group++) {
 tmp_group_props[group].sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_GROUP_PROPERTIES;
 uint32_t cur_index = group + cur_icd_group_count;
 if (*pPhysicalDeviceGroupCount > cur_index) {
 tmp_group_props[group].pNext = pPhysicalDeviceGroupProperties[cur_index].pNext;
 } else {
 tmp_group_props[group].pNext = NULL;
 }
 tmp_group_props[group].subsetAllocation = false;
 }

 res = fpEnumeratePhysicalDeviceGroups(icd_term->instance, &count_this_time, tmp_group_props);
 if (res != VK_SUCCESS) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDeviceGroups\' to ICD %s to get group information for temp data.",
 icd_term->scanned_icd->lib_name);
 goto out;
 }
 for (uint32_t group = 0; group < count_this_time; ++group) {
 uint32_t cur_index = group + cur_icd_group_count;
 local_phys_dev_groups[cur_index].group_props = tmp_group_props[group];
 // physicalDevices is a fixed VK_MAX_DEVICE_GROUP_SIZE array; don't trust a larger count from the ICD.
 if (local_phys_dev_groups[cur_index].group_props.physicalDeviceCount > VK_MAX_DEVICE_GROUP_SIZE) {
 local_phys_dev_groups[cur_index].group_props.physicalDeviceCount = VK_MAX_DEVICE_GROUP_SIZE;
 }
 local_phys_dev_groups[cur_index].this_icd_term = icd_term;
 }
 }
 if (VK_SUCCESS != res) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed during dispatch call of "
 "\'EnumeratePhysicalDeviceGroups\' to ICD %s to get content.",
 icd_term->scanned_icd->lib_name);
 goto out;
 }
 }

 cur_icd_group_count += count_this_time;
 icd_term = icd_term->next;
 }

#if defined(LOADER_ENABLE_LINUX_SORT)
 if (is_linux_sort_enabled(inst)) {
 // Get the physical devices supported by platform sorting mechanism into a separate list
 res = linux_sort_physical_device_groups(inst, total_count, local_phys_dev_groups);
 }
#elif defined(_WIN32)
 // The Windows sorting information is only on physical devices. We need to take that and convert it to the group
 // information if it's present.
 if (sorted_count > 0) {
 res =
 windows_sort_physical_device_groups(inst, total_count, local_phys_dev_groups, sorted_count, sorted_phys_dev_array);
 }
#endif // LOADER_ENABLE_LINUX_SORT

 // Just to be safe, make sure we successfully completed setup_loader_term_phys_devs above
 // before attempting to do the following. By verifying that setup_loader_term_phys_devs ran
 // first, it guarantees that each physical device will have a loader-specific handle.
 if (NULL != inst->phys_devs_term) {
 for (uint32_t group = 0; group < total_count; group++) {
 for (uint32_t group_gpu = 0; group_gpu < local_phys_dev_groups[group].group_props.physicalDeviceCount;
 group_gpu++) {
 bool found = false;
 for (uint32_t term_gpu = 0; term_gpu < inst->phys_dev_count_term; term_gpu++) {
 if (local_phys_dev_groups[group].group_props.physicalDevices[group_gpu] ==
 inst->phys_devs_term[term_gpu]->phys_dev) {
 local_phys_dev_groups[group].group_props.physicalDevices[group_gpu] =
 (VkPhysicalDevice)inst->phys_devs_term[term_gpu];
 found = true;
 break;
 }
 }
 if (!found) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed to find GPU %d in group %d returned by "
 "\'EnumeratePhysicalDeviceGroups\' in list returned by \'EnumeratePhysicalDevices\'",
 group_gpu, group);
 res = VK_ERROR_INITIALIZATION_FAILED;
 goto out;
 }
 }
 }
 }

 uint32_t idx = 0;

 // Copy or create everything to fill the new array of physical device groups
 for (uint32_t group = 0; group < total_count; group++) {
 // Skip groups which have been included through sorting
 if (local_phys_dev_groups[group].group_props.physicalDeviceCount == 0) {
 continue;
 }

 // Find the VkPhysicalDeviceGroupProperties object in local_phys_dev_groups
 VkPhysicalDeviceGroupProperties *group_properties = &local_phys_dev_groups[group].group_props;

 // Check if this physical device group with the same contents is already in the old buffer
 for (uint32_t old_idx = 0; old_idx < inst->phys_dev_group_count_term; old_idx++) {
 if (NULL != group_properties && NULL != inst->phys_dev_groups_term[old_idx] &&
 group_properties->physicalDeviceCount == inst->phys_dev_groups_term[old_idx]->physicalDeviceCount) {
 bool found_all_gpus = true;
 for (uint32_t old_gpu = 0; old_gpu < inst->phys_dev_groups_term[old_idx]->physicalDeviceCount; old_gpu++) {
 bool found_gpu = false;
 for (uint32_t new_gpu = 0; new_gpu < group_properties->physicalDeviceCount; new_gpu++) {
 if (group_properties->physicalDevices[new_gpu] ==
 inst->phys_dev_groups_term[old_idx]->physicalDevices[old_gpu]) {
 found_gpu = true;
 break;
 }
 }

 if (!found_gpu) {
 found_all_gpus = false;
 break;
 }
 }
 if (!found_all_gpus) {
 continue;
 } else {
 new_phys_dev_groups[idx] = inst->phys_dev_groups_term[old_idx];
 break;
 }
 }
 }
 // If this physical device group isn't in the old buffer, create it
 if (group_properties != NULL && NULL == new_phys_dev_groups[idx]) {
 new_phys_dev_groups[idx] = (VkPhysicalDeviceGroupProperties *)loader_instance_heap_alloc(
 inst, sizeof(VkPhysicalDeviceGroupProperties), VK_SYSTEM_ALLOCATION_SCOPE_INSTANCE);
 if (NULL == new_phys_dev_groups[idx]) {
 loader_log(inst, VULKAN_LOADER_ERROR_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups: Failed to allocate physical device group Terminator "
 "object %d",
 idx);
 total_count = idx;
 res = VK_ERROR_OUT_OF_HOST_MEMORY;
 goto out;
 }
 memcpy(new_phys_dev_groups[idx], group_properties, sizeof(VkPhysicalDeviceGroupProperties));
 }

 ++idx;
 }
 }

out:

 if (NULL != pPhysicalDeviceGroupProperties) {
 if (VK_SUCCESS != res) {
 if (NULL != new_phys_dev_groups) {
 // We've encountered an error, so we should free the new buffers.
 for (uint32_t i = 0; i < total_count; i++) {
 // If an OOM occurred inside the copying of the new physical device groups into the existing array will
 // leave some of the old physical device groups in the array which may have been copied into the new array,
 // leading to them being freed twice. To avoid this we just make sure to not delete physical device groups
 // which were copied.
 bool found = false;
 if (NULL != inst->phys_devs_term) {
 for (uint32_t old_idx = 0; old_idx < inst->phys_dev_group_count_term; old_idx++) {
 if (new_phys_dev_groups[i] == inst->phys_dev_groups_term[old_idx]) {
 found = true;
 break;
 }
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, new_phys_dev_groups[i]);
 }
 }
 loader_instance_heap_free(inst, new_phys_dev_groups);
 }
 } else {
 if (NULL != inst->phys_dev_groups_term) {
 // Free everything in the old array that was not copied into the new array
 // here. We can't attempt to do that before here since the previous loop
 // looking before the "out:" label may hit an out of memory condition resulting
 // in memory leaking.
 for (uint32_t i = 0; i < inst->phys_dev_group_count_term; i++) {
 bool found = false;
 for (uint32_t j = 0; j < total_count; j++) {
 if (inst->phys_dev_groups_term[i] == new_phys_dev_groups[j]) {
 found = true;
 break;
 }
 }
 if (!found) {
 loader_instance_heap_free(inst, inst->phys_dev_groups_term[i]);
 }
 }
 loader_instance_heap_free(inst, inst->phys_dev_groups_term);
 }

 // Swap in the new physical device group list
 inst->phys_dev_group_count_term = total_count;
 inst->phys_dev_groups_term = new_phys_dev_groups;
 }

 if (sorted_phys_dev_array != NULL) {
 for (uint32_t i = 0; i < sorted_count; ++i) {
 if (sorted_phys_dev_array[i].device_count > 0 && sorted_phys_dev_array[i].physical_devices != NULL) {
 loader_instance_heap_free(inst, sorted_phys_dev_array[i].physical_devices);
 }
 }
 loader_instance_heap_free(inst, sorted_phys_dev_array);
 }

 uint32_t copy_count = inst->phys_dev_group_count_term;
 if (NULL != pPhysicalDeviceGroupProperties) {
 if (copy_count > *pPhysicalDeviceGroupCount) {
 copy_count = *pPhysicalDeviceGroupCount;
 loader_log(inst, VULKAN_LOADER_INFO_BIT, 0,
 "terminator_EnumeratePhysicalDeviceGroups : Trimming device count from %d to %d.",
 inst->phys_dev_group_count_term, copy_count);
 res = VK_INCOMPLETE;
 }

 for (uint32_t i = 0; i < copy_count; i++) {
 memcpy(&pPhysicalDeviceGroupProperties[i], inst->phys_dev_groups_term[i], sizeof(VkPhysicalDeviceGroupProperties));
 }
 }

 *pPhysicalDeviceGroupCount = copy_count;

 } else {
 *pPhysicalDeviceGroupCount = total_count;
 }
 return res;
}

VkResult get_device_driver_id(VkPhysicalDevice physicalDevice, VkDriverId *driverId) {
 VkPhysicalDeviceDriverProperties physical_device_driver_props = {0};
 physical_device_driver_props.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES;

 VkPhysicalDeviceProperties2 props2 = {0};
 props2.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2;
 props2.pNext = &physical_device_driver_props;

 struct loader_physical_device_term *phys_dev_term = (struct loader_physical_device_term *)physicalDevice;
 struct loader_icd_term *icd_term = phys_dev_term->this_icd_term;
 const struct loader_instance *inst = icd_term->this_instance;

 assert(inst != NULL);

 // Get the function pointer to use to call into the ICD. This could be the core or KHR version
 PFN_vkGetPhysicalDeviceProperties2 fpGetPhysicalDeviceProperties2 = NULL;
 if (loader_check_version_meets_required(LOADER_VERSION_1_1_0, inst->app_api_version)) {
 fpGetPhysicalDeviceProperties2 = icd_term->dispatch.GetPhysicalDeviceProperties2;
 }
 if (fpGetPhysicalDeviceProperties2 == NULL && inst->enabled_extensions.khr_get_physical_device_properties2) {
 fpGetPhysicalDeviceProperties2 = icd_term->dispatch.GetPhysicalDeviceProperties2KHR;
 }

 if (fpGetPhysicalDeviceProperties2 == NULL) {
 *driverId = 0;
 return VK_ERROR_UNKNOWN;
 }

 fpGetPhysicalDeviceProperties2(phys_dev_term->phys_dev, &props2);

 *driverId = physical_device_driver_props.driverID;
 return VK_SUCCESS;
}

VkResult loader_filter_enumerated_physical_device(const struct loader_instance *inst,
 const struct loader_envvar_id_filter *device_id_filter,
 const struct loader_envvar_id_filter *vendor_id_filter,
 const struct loader_envvar_id_filter *driver_id_filter,
 const uint32_t in_PhysicalDeviceCount,
 const VkPhysicalDevice *in_pPhysicalDevices, uint32_t *out_pPhysicalDeviceCount,
 VkPhysicalDevice *out_pPhysicalDevices) {
 uint32_t filtered_physical_device_count = 0;
 for (uint32_t i = 0; i < in_PhysicalDeviceCount; i++) {
 VkPhysicalDeviceProperties dev_props = {0};
 inst->disp->layer_inst_disp.GetPhysicalDeviceProperties(in_pPhysicalDevices[i], &dev_props);

 if ((0 != device_id_filter->count) && !check_id_matches_filter_environment_var(dev_props.deviceID, device_id_filter)) {
 continue;
 }

 if ((0 != vendor_id_filter->count) && !check_id_matches_filter_environment_var(dev_props.vendorID, vendor_id_filter)) {
 continue;
 }

 if (0 != driver_id_filter->count) {
 VkDriverId driver_id;
 VkResult res = get_device_driver_id(in_pPhysicalDevices[i], &driver_id);

 if ((res != VK_SUCCESS) || !check_id_matches_filter_environment_var(driver_id, driver_id_filter)) {
 continue;
 }
 }

 if ((NULL != out_pPhysicalDevices) && (filtered_physical_device_count < *out_pPhysicalDeviceCount)) {
 out_pPhysicalDevices[filtered_physical_device_count] = in_pPhysicalDevices[i];
 }
 filtered_physical_device_count++;
 }

 if ((NULL == out_pPhysicalDevices) || (filtered_physical_device_count < *out_pPhysicalDeviceCount)) {
 *out_pPhysicalDeviceCount = filtered_physical_device_count;
 }

 return (*out_pPhysicalDeviceCount < filtered_physical_device_count) ? VK_INCOMPLETE : VK_SUCCESS;
}

VkResult loader_filter_enumerated_physical_device_groups(
 const struct loader_instance *inst, const struct loader_envvar_id_filter *device_id_filter,
 const struct loader_envvar_id_filter *vendor_id_filter, const struct loader_envvar_id_filter *driver_id_filter,
 const uint32_t in_PhysicalDeviceGroupCount, const VkPhysicalDeviceGroupProperties *in_pPhysicalDeviceGroupProperties,
 uint32_t *out_PhysicalDeviceGroupCount, VkPhysicalDeviceGroupProperties *out_pPhysicalDeviceGroupProperties) {
 uint32_t filtered_physical_device_group_count = 0;
 for (uint32_t i = 0; i < in_PhysicalDeviceGroupCount; i++) {
 const VkPhysicalDeviceGroupProperties *device_group = &in_pPhysicalDeviceGroupProperties[i];

 bool skip_group = false;
 for (uint32_t j = 0; j < device_group->physicalDeviceCount; j++) {
 VkPhysicalDeviceProperties dev_props = {0};
 inst->disp->layer_inst_disp.GetPhysicalDeviceProperties(device_group->physicalDevices[j], &dev_props);

 if ((0 != device_id_filter->count) && !check_id_matches_filter_environment_var(dev_props.deviceID, device_id_filter)) {
 skip_group = true;
 break;
 }

 if ((0 != vendor_id_filter->count) && !check_id_matches_filter_environment_var(dev_props.vendorID, vendor_id_filter)) {
 skip_group = true;
 break;
 }

 if (0 != driver_id_filter->count) {
 VkDriverId driver_id;
 VkResult res = get_device_driver_id(device_group->physicalDevices[j], &driver_id);

 if ((res != VK_SUCCESS) || !check_id_matches_filter_environment_var(driver_id, driver_id_filter)) {
 skip_group = true;
 break;
 }
 }
 }

 if (skip_group) {
 continue;
 }

 if ((NULL != out_pPhysicalDeviceGroupProperties) &&
 (filtered_physical_device_group_count < *out_PhysicalDeviceGroupCount)) {
 out_pPhysicalDeviceGroupProperties[filtered_physical_device_group_count] = *device_group;
 }

 filtered_physical_device_group_count++;
 }

 if ((NULL == out_pPhysicalDeviceGroupProperties) || (filtered_physical_device_group_count < *out_PhysicalDeviceGroupCount)) {
 *out_PhysicalDeviceGroupCount = filtered_physical_device_group_count;
 }

 return (*out_PhysicalDeviceGroupCount < filtered_physical_device_group_count) ? VK_INCOMPLETE : VK_SUCCESS;
}