text: /*
   *
   * Copyright (c) 2015-2018 The Khronos Group Inc.
   * Copyright (c) 2015-2018 Valve Corporation
   * Copyright (c) 2015-2018 LunarG, Inc.
   *
   * 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: Ian Elliot <ian@lunarg.com>
   * Author: Jon Ashburn <jon@lunarg.com>
   * Author: Lenny Komow <lenny@lunarg.com>
   *
   */
  #pragma once
  
  #if defined(_WIN32)
  // WinSock2.h must be included *BEFORE* windows.h
  #include <winsock2.h>
  #endif  // _WIN32
  
  #include "vulkan/vk_platform.h"
  #include "vulkan/vk_sdk_platform.h"
  
  #if defined(__linux__) || defined(__APPLE__)
  /* Linux-specific common code: */
  
  // Headers:
  //#ifndef _GNU_SOURCE
  //#define _GNU_SOURCE 1
  //#endif
  #include <unistd.h>
  // Note: The following file is for dynamic loading:
  #include <dlfcn.h>
  #include <pthread.h>
  #include <assert.h>
  #include <string.h>
  #include <stdbool.h>
  #include <stdlib.h>
  #include <libgen.h>
  
  // VK Library Filenames, Paths, etc.:
  #define PATH_SEPARATOR ':'
  #define DIRECTORY_SYMBOL '/'
  
  #define VULKAN_DIR "vulkan/"
  #define VULKAN_ICDCONF_DIR "icd.d"
  #define VULKAN_ICD_DIR "icd"
  #define VULKAN_SETTINGSCONF_DIR "settings.d"
  #define VULKAN_ELAYERCONF_DIR "explicit_layer.d"
  #define VULKAN_ILAYERCONF_DIR "implicit_layer.d"
  #define VULKAN_LAYER_DIR "layer"
  
  #define VK_DRIVERS_INFO_RELATIVE_DIR VULKAN_DIR VULKAN_ICDCONF_DIR
  #define VK_SETTINGS_INFO_RELATIVE_DIR VULKAN_DIR VULKAN_SETTINGSCONF_DIR
  #define VK_ELAYERS_INFO_RELATIVE_DIR VULKAN_DIR VULKAN_ELAYERCONF_DIR
  #define VK_ILAYERS_INFO_RELATIVE_DIR VULKAN_DIR VULKAN_ILAYERCONF_DIR
  
  #define VK_DRIVERS_INFO_REGISTRY_LOC ""
  #define VK_SETTINGS_INFO_REGISTRY_LOC ""
  #define VK_ELAYERS_INFO_REGISTRY_LOC ""
  #define VK_ILAYERS_INFO_REGISTRY_LOC ""
  
  #if !defined(DEFAULT_VK_LAYERS_PATH)
  #define DEFAULT_VK_LAYERS_PATH ""
  #endif
  #if !defined(LAYERS_SOURCE_PATH)
  #define LAYERS_SOURCE_PATH NULL
  #endif
  #define LAYERS_PATH_ENV "VK_LAYER_PATH"
  #define ENABLED_LAYERS_ENV "VK_INSTANCE_LAYERS"
  
  // C99:
  #define PRINTF_SIZE_T_SPECIFIER "%zu"
  
  // File IO
  static inline bool loader_platform_file_exists(const char *path) {
      if (access(path, F_OK))
          return false;
      else
          return true;
  }
  
  static inline bool loader_platform_is_path_absolute(const char *path) {
      if (path[0] == '/')
          return true;
      else
          return false;
  }
  
  static inline char *loader_platform_dirname(char *path) { return dirname(path); }
  
  #if defined(__linux__)
  
  // find application path + name. Path cannot be longer than 1024, returns NULL if it is greater than that.
  static inline char *loader_platform_executable_path(char *buffer, size_t size) {
      ssize_t count = readlink("/proc/self/exe", buffer, size);
      if (count == -1) return NULL;
      if (count == 0) return NULL;
      buffer[count] = '\0';
      return buffer;
  }
  #elif defined(__APPLE__)  // defined(__linux__)
  #include <libproc.h>
  static inline char *loader_platform_executable_path(char *buffer, size_t size) {
      pid_t pid = getpid();
      int ret = proc_pidpath(pid, buffer, size);
      if (ret <= 0) return NULL;
      buffer[ret] = '\0';
      return buffer;
  }
  #endif  // defined (__APPLE__)
  
  // Compatability with compilers that don't support __has_feature
  #ifndef __has_feature
  #define __has_feature(x) 0
  #endif
  
  #if __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
  #define LOADER_ADDRESS_SANITIZER
  #endif
  
  // Dynamic Loading of libraries:
  typedef void *loader_platform_dl_handle;
  static inline loader_platform_dl_handle loader_platform_open_library(const char *libPath) {
  // When loading the library, we use RTLD_LAZY so that not all symbols have to be
  // resolved at this time (which improves performance). Note that if not all symbols
  // can be resolved, this could cause crashes later. Use the LD_BIND_NOW environment
  // variable to force all symbols to be resolved here.
      return dlopen(libPath, RTLD_LAZY | RTLD_LOCAL);
  }
  static inline const char *loader_platform_open_library_error(const char *libPath) { return dlerror(); }
  static inline void loader_platform_close_library(loader_platform_dl_handle library) { dlclose(library); }
  static inline void *loader_platform_get_proc_address(loader_platform_dl_handle library, const char *name) {
      assert(library);
      assert(name);
      return dlsym(library, name);
  }
  static inline const char *loader_platform_get_proc_address_error(const char *name) { return dlerror(); }
  
  // Threads:
  typedef pthread_t loader_platform_thread;
  #define THREAD_LOCAL_DECL __thread
  
  // The once init functionality is not used on Linux
  #define LOADER_PLATFORM_THREAD_ONCE_DECLARATION(var)
  #define LOADER_PLATFORM_THREAD_ONCE_DEFINITION(var)
  #define LOADER_PLATFORM_THREAD_ONCE(ctl, func)
  
  // Thread IDs:
  typedef pthread_t loader_platform_thread_id;
  static inline loader_platform_thread_id loader_platform_get_thread_id() { return pthread_self(); }
  
  // Thread mutex:
  typedef pthread_mutex_t loader_platform_thread_mutex;
  static inline void loader_platform_thread_create_mutex(loader_platform_thread_mutex *pMutex) { pthread_mutex_init(pMutex, NULL); }
  static inline void loader_platform_thread_lock_mutex(loader_platform_thread_mutex *pMutex) { pthread_mutex_lock(pMutex); }
  static inline void loader_platform_thread_unlock_mutex(loader_platform_thread_mutex *pMutex) { pthread_mutex_unlock(pMutex); }
  static inline void loader_platform_thread_delete_mutex(loader_platform_thread_mutex *pMutex) { pthread_mutex_destroy(pMutex); }
  typedef pthread_cond_t loader_platform_thread_cond;
  static inline void loader_platform_thread_init_cond(loader_platform_thread_cond *pCond) { pthread_cond_init(pCond, NULL); }
  static inline void loader_platform_thread_cond_wait(loader_platform_thread_cond *pCond, loader_platform_thread_mutex *pMutex) {
      pthread_cond_wait(pCond, pMutex);
  }
  static inline void loader_platform_thread_cond_broadcast(loader_platform_thread_cond *pCond) { pthread_cond_broadcast(pCond); }
  
  #define loader_stack_alloc(size) alloca(size)
  
  #elif defined(_WIN32)  // defined(__linux__)
  /* Windows-specific common code: */
  // WinBase.h defines CreateSemaphore and synchapi.h defines CreateEvent
  //  undefine them to avoid conflicts with VkLayerDispatchTable struct members.
  #ifdef CreateSemaphore
  #undef CreateSemaphore
  #endif
  #ifdef CreateEvent
  #undef CreateEvent
  #endif
  #include <assert.h>
  #include <stdio.h>
  #include <string.h>
  #include <io.h>
  #include <stdbool.h>
  #include <shlwapi.h>
  #include <direct.h>
  #ifdef __cplusplus
  #include <iostream>
  #include <string>
  #endif  // __cplusplus
  
  // VK Library Filenames, Paths, etc.:
  #define PATH_SEPARATOR ';'
  #define DIRECTORY_SYMBOL '\\'
  #define DEFAULT_VK_REGISTRY_HIVE HKEY_LOCAL_MACHINE
  #define DEFAULT_VK_REGISTRY_HIVE_STR "HKEY_LOCAL_MACHINE"
  #define SECONDARY_VK_REGISTRY_HIVE HKEY_CURRENT_USER
  #define SECONDARY_VK_REGISTRY_HIVE_STR "HKEY_CURRENT_USER"
  
  #define VK_DRIVERS_INFO_RELATIVE_DIR ""
  #define VK_SETTINGS_INFO_RELATIVE_DIR ""
  #define VK_ELAYERS_INFO_RELATIVE_DIR ""
  #define VK_ILAYERS_INFO_RELATIVE_DIR ""
  
  #ifdef _WIN64
  #define HKR_VK_DRIVER_NAME API_NAME "DriverName"
  #else
  #define HKR_VK_DRIVER_NAME API_NAME "DriverNameWow"
  #endif
  #define VK_DRIVERS_INFO_REGISTRY_LOC "SOFTWARE\\Khronos\\" API_NAME "\\Drivers"
  #define VK_SETTINGS_INFO_REGISTRY_LOC "SOFTWARE\\Khronos\\" API_NAME "\\Settings"
  #define VK_ELAYERS_INFO_REGISTRY_LOC "SOFTWARE\\Khronos\\" API_NAME "\\ExplicitLayers"
  #define VK_ILAYERS_INFO_REGISTRY_LOC "SOFTWARE\\Khronos\\" API_NAME "\\ImplicitLayers"
  
  #if !defined(DEFAULT_VK_LAYERS_PATH)
  #define DEFAULT_VK_LAYERS_PATH ""
  #endif
  #if !defined(LAYERS_SOURCE_PATH)
  #define LAYERS_SOURCE_PATH NULL
  #endif
  #define LAYERS_PATH_ENV "VK_LAYER_PATH"
  #define ENABLED_LAYERS_ENV "VK_INSTANCE_LAYERS"
  
  #define PRINTF_SIZE_T_SPECIFIER "%Iu"
  
  #if defined(_WIN32)
  // Get the key for the plug n play driver registry
  // The string returned by this function should NOT be freed
  static inline const char *LoaderPnpDriverRegistry() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? "VulkanDriverNameWow" : "VulkanDriverName";
  }
  static inline const wchar_t *LoaderPnpDriverRegistryWide() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? L"VulkanDriverNameWow" : L"VulkanDriverName";
  }
  
  // Get the key for the plug 'n play explicit layer registry
  // The string returned by this function should NOT be freed
  static inline const char *LoaderPnpELayerRegistry() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? "VulkanExplicitLayersWow" : "VulkanExplicitLayers";
  }
  static inline const wchar_t *LoaderPnpELayerRegistryWide() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? L"VulkanExplicitLayersWow" : L"VulkanExplicitLayers";
  }
  
  // Get the key for the plug 'n play implicit layer registry
  // The string returned by this function should NOT be freed
  static inline const char *LoaderPnpILayerRegistry() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? "VulkanImplicitLayersWow" : "VulkanImplicitLayers";
  }
  static inline const wchar_t *LoaderPnpILayerRegistryWide() {
      BOOL is_wow;
      IsWow64Process(GetCurrentProcess(), &is_wow);
      return is_wow ? L"VulkanImplicitLayersWow" : L"VulkanImplicitLayers";
  }
  #endif
  
  // File IO
  static bool loader_platform_file_exists(const char *path) {
      if ((_access(path, 0)) == -1)
          return false;
      else
          return true;
  }
  
  static bool loader_platform_is_path_absolute(const char *path) {
      if (!path || !*path) {
          return false;
      }
      if (*path == DIRECTORY_SYMBOL || path[1] == ':') {
          return true;
      }
      return false;
  }
  
  // WIN32 runtime doesn't have dirname().
  static inline char *loader_platform_dirname(char *path) {
      char *current, *next;
  
      // TODO/TBD: Do we need to deal with the Windows's ":" character?
  
      for (current = path; *current != '\0'; current = next) {
          next = strchr(current, DIRECTORY_SYMBOL);
          if (next == NULL) {
              if (current != path) *(current - 1) = '\0';
              return path;
          } else {
              // Point one character past the DIRECTORY_SYMBOL:
              next++;
          }
      }
      return path;
  }
  
  static inline char *loader_platform_executable_path(char *buffer, size_t size) {
      DWORD ret = GetModuleFileName(NULL, buffer, (DWORD)size);
      if (ret == 0) return NULL;
      if (ret > size) return NULL;
      buffer[ret] = '\0';
      return buffer;
  }
  
  // Dynamic Loading:
  typedef HMODULE loader_platform_dl_handle;
  static loader_platform_dl_handle loader_platform_open_library(const char *lib_path) {
      // Try loading the library the original way first.
      loader_platform_dl_handle lib_handle = LoadLibrary(lib_path);
      if (lib_handle == NULL && GetLastError() == ERROR_MOD_NOT_FOUND) {
          // If that failed, then try loading it with broader search folders.
          lib_handle = LoadLibraryEx(lib_path, NULL, LOAD_LIBRARY_SEARCH_DEFAULT_DIRS | LOAD_LIBRARY_SEARCH_DLL_LOAD_DIR);
      }
      return lib_handle;
  }
  static char *loader_platform_open_library_error(const char *libPath) {
      static char errorMsg[164];
      (void)snprintf(errorMsg, 163, "Failed to open dynamic library \"%s\" with error %lu", libPath, GetLastError());
      return errorMsg;
  }
  static void loader_platform_close_library(loader_platform_dl_handle library) { FreeLibrary(library); }
  static void *loader_platform_get_proc_address(loader_platform_dl_handle library, const char *name) {
      assert(library);
      assert(name);
      return (void *)GetProcAddress(library, name);
  }
  static char *loader_platform_get_proc_address_error(const char *name) {
      static char errorMsg[120];
      (void)snprintf(errorMsg, 119, "Failed to find function \"%s\" in dynamic library", name);
      return errorMsg;
  }
  
  // Threads:
  typedef HANDLE loader_platform_thread;
  
  // __declspec(thread) is not supported by MinGW compiler (ignored with warning or
  //                    cause error depending on compiler switches)
  //
  // __thread should be used instead
  //
  // __MINGW32__ defined for both 32 and 64 bit MinGW compilers, so it is enough to
  // detect any (32 or 64) flavor of MinGW compiler.
  //
  // @note __GNUC__ could be used as a more generic way to detect _any_
  //       GCC[-compatible] compiler on Windows, but this fix was tested
  //       only with MinGW, so keep it explicit at the moment.
  #if defined(__MINGW32__)
  #define THREAD_LOCAL_DECL __thread
  #else
  #define THREAD_LOCAL_DECL __declspec(thread)
  #endif
  
  // The once init functionality is not used when building a DLL on Windows. This is because there is no way to clean up the
  // resources allocated by anything allocated by once init. This isn't a problem for static libraries, but it is for dynamic
  // ones. When building a DLL, we use DllMain() instead to allow properly cleaning up resources.
  #if defined(LOADER_DYNAMIC_LIB)
  #define LOADER_PLATFORM_THREAD_ONCE_DECLARATION(var)
  #define LOADER_PLATFORM_THREAD_ONCE_DEFINITION(var)
  #define LOADER_PLATFORM_THREAD_ONCE(ctl, func)
  #else
  #define LOADER_PLATFORM_THREAD_ONCE_DECLARATION(var) INIT_ONCE var = INIT_ONCE_STATIC_INIT;
  #define LOADER_PLATFORM_THREAD_ONCE_DEFINITION(var) INIT_ONCE var;
  #define LOADER_PLATFORM_THREAD_ONCE(ctl, func) loader_platform_thread_once_fn(ctl, func)
  static BOOL CALLBACK InitFuncWrapper(PINIT_ONCE InitOnce, PVOID Parameter, PVOID *Context) {
      void (*func)(void) = (void (*)(void))Parameter;
      func();
      return TRUE;
  }
  static void loader_platform_thread_once_fn(void *ctl, void (*func)(void)) {
      assert(func != NULL);
      assert(ctl != NULL);
      InitOnceExecuteOnce((PINIT_ONCE)ctl, InitFuncWrapper, (void *)func, NULL);
  }
  #endif
  
  // Thread IDs:
  typedef DWORD loader_platform_thread_id;
  static loader_platform_thread_id loader_platform_get_thread_id() { return GetCurrentThreadId(); }
  
  // Thread mutex:
  typedef CRITICAL_SECTION loader_platform_thread_mutex;
  static void loader_platform_thread_create_mutex(loader_platform_thread_mutex *pMutex) { InitializeCriticalSection(pMutex); }
  static void loader_platform_thread_lock_mutex(loader_platform_thread_mutex *pMutex) { EnterCriticalSection(pMutex); }
  static void loader_platform_thread_unlock_mutex(loader_platform_thread_mutex *pMutex) { LeaveCriticalSection(pMutex); }
  static void loader_platform_thread_delete_mutex(loader_platform_thread_mutex *pMutex) { DeleteCriticalSection(pMutex); }
  typedef CONDITION_VARIABLE loader_platform_thread_cond;
  static void loader_platform_thread_init_cond(loader_platform_thread_cond *pCond) { InitializeConditionVariable(pCond); }
  static void loader_platform_thread_cond_wait(loader_platform_thread_cond *pCond, loader_platform_thread_mutex *pMutex) {
      SleepConditionVariableCS(pCond, pMutex, INFINITE);
  }
  static void loader_platform_thread_cond_broadcast(loader_platform_thread_cond *pCond) { WakeAllConditionVariable(pCond); }
  
  #define loader_stack_alloc(size) _alloca(size)
  #else  // defined(_WIN32)
  
  #error The "loader_platform.h" file must be modified for this OS.
  
  // NOTE: In order to support another OS, an #elif needs to be added (above the
  // "#else // defined(_WIN32)") for that OS, and OS-specific versions of the
  // contents of this file must be created.
  
  // NOTE: Other OS-specific changes are also needed for this OS.  Search for
  // files with "WIN32" in it, as a quick way to find files that must be changed.
  
  #endif  // defined(_WIN32)
  
  // returns true if the given string appears to be a relative or absolute
  // path, as opposed to a bare filename.
  static inline bool loader_platform_is_path(const char *path) { return strchr(path, DIRECTORY_SYMBOL) != NULL; }
  