[macOS] Build infrastructure and portability fixes

Build system:
- Enable ObjC++, macOS deployment target, framework linking
- Fix AppleClang detection
- macOS platform name for output directories
- Skip Vulkan on macOS, null graphics without Vulkan dependency
- macOS SDL2 framework detection and discord-rpc macOS sources

Portability fixes:
- mach_absolute_time for macOS tick counting
- _NSGetExecutablePath for macOS
- guard MAP_FIXED_NOREPLACE, ftruncate64->ftruncate
- guard Vulkan include/usage, fix data root for all POSIX

CMakeLists.txt

@@ -1,5 +1,11 @@
 cmake_minimum_required(VERSION 3.20)
-project(xenia LANGUAGES C CXX)
+if(APPLE)
+  project(xenia LANGUAGES C CXX OBJCXX)
+  set(CMAKE_OBJCXX_STANDARD 20)
+  set(CMAKE_OBJCXX_STANDARD_REQUIRED ON)
+else()
+  project(xenia LANGUAGES C CXX)
+endif()
 
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -52,6 +58,8 @@ set(CMAKE_STATIC_LINKER_FLAGS_CHECKED "${CMAKE_STATIC_LINKER_FLAGS_DEBUG}" CACHE
 # Platform name for output paths
 if(WIN32)
   set(XE_PLATFORM_NAME "Windows")
+elseif(APPLE)
+  set(XE_PLATFORM_NAME "macOS")
 else()
   set(XE_PLATFORM_NAME "Linux")
 endif()
@@ -178,7 +186,7 @@ else()
   )
 
   # Clang-specific C++ warnings
-  if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
     add_compile_options(
       $<$<COMPILE_LANGUAGE:CXX>:-Wno-deprecated-register>
       $<$<COMPILE_LANGUAGE:CXX>:-Wno-deprecated-volatile>
@@ -216,7 +224,23 @@ else()
     $<$<COMPILE_LANGUAGE:C>:-Wno-implicit-function-declaration>
   )
 
-  if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+  if(APPLE)
+    # macOS-specific settings
+    set(CMAKE_OSX_DEPLOYMENT_TARGET "15.0" CACHE STRING "Minimum macOS version")
+    add_compile_options(
+      $<$<COMPILE_LANGUAGE:CXX>:-Wno-shorten-64-to-32>
+      -Wno-deprecated-declarations
+      -Wno-character-conversion
+    )
+    add_link_options(-Wl,-no_warn_duplicate_libraries)
+    link_libraries(
+      "-framework CoreFoundation"
+      "-framework Foundation"
+      "-framework IOKit"
+      dl
+      pthread
+    )
+  elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     # GTK3 via pkg-config
     find_package(PkgConfig REQUIRED)
     pkg_check_modules(GTK3 REQUIRED gtk+-x11-3.0)

src/xenia/app/xenia_main.cc

@@ -48,7 +48,9 @@
 
 // Available graphics systems:
 #include "xenia/gpu/null/null_graphics_system.h"
+#if !XE_PLATFORM_MAC
 #include "xenia/gpu/vulkan/vulkan_graphics_system.h"
+#endif
 #if XE_PLATFORM_WIN32
 #include "xenia/gpu/d3d12/d3d12_graphics_system.h"
 #endif  // XE_PLATFORM_WIN32
@@ -401,7 +403,9 @@ std::unique_ptr<gpu::GraphicsSystem> EmulatorApp::CreateGraphicsSystem() {
 #if XE_PLATFORM_WIN32
   factory.Add<gpu::d3d12::D3D12GraphicsSystem>("d3d12");
 #endif  // XE_PLATFORM_WIN32
+#if !XE_PLATFORM_MAC
   factory.Add<gpu::vulkan::VulkanGraphicsSystem>("vulkan");
+#endif
   std::unique_ptr<gpu::GraphicsSystem> gpu_implementation =
       factory.Create(gpu_implementation_name);
   if (!gpu_implementation) {
@@ -475,12 +479,9 @@ bool EmulatorApp::OnInitialize() {
     if (!cvars::portable &&
         !std::filesystem::exists(storage_root / "portable.txt")) {
       storage_root = xe::filesystem::GetUserFolder();
-#if defined(XE_PLATFORM_WIN32) || defined(XE_PLATFORM_LINUX)
-      storage_root = storage_root / "Xenia";
+#if XE_PLATFORM_ANDROID
+      // TODO(Triang3l): Point to the app's external storage "files" directory.
 #else
-      // TODO(Triang3l): Point to the app's external storage "files" directory
-      // on Android.
-#warning Unhandled platform for the data root.
       storage_root = storage_root / "Xenia";
 #endif
     }

src/xenia/base/clock_posix.cc

@@ -8,6 +8,9 @@
  */
 
 #include <sys/time.h>
+#ifdef __APPLE__
+#include <mach/mach_time.h>
+#endif
 
 #include "xenia/base/assert.h"
 #include "xenia/base/clock.h"
@@ -15,6 +18,12 @@
 namespace xe {
 
 uint64_t Clock::host_tick_frequency_platform() {
+#ifdef __APPLE__
+  mach_timebase_info_data_t info;
+  mach_timebase_info(&info);
+  return (uint64_t)((1000000000ull * (uint64_t)info.denom) /
+                    (uint64_t)info.numer);
+#else
   timespec res;
   int error = clock_getres(CLOCK_MONOTONIC_RAW, &res);
   assert_zero(error);
@@ -22,14 +31,19 @@ uint64_t Clock::host_tick_frequency_platform() {
 
   // Convert nano seconds to hertz. Resolution is 1ns on most systems.
   return 1000000000ull / res.tv_nsec;
+#endif
 }
 
 uint64_t Clock::host_tick_count_platform() {
+#ifdef __APPLE__
+  return mach_absolute_time();
+#else
   timespec tp;
   int error = clock_gettime(CLOCK_MONOTONIC_RAW, &tp);
   assert_zero(error);
 
   return tp.tv_nsec + tp.tv_sec * 1000000000ull;
+#endif
 }
 
 uint64_t Clock::QueryHostSystemTime() {

src/xenia/base/filesystem_posix.cc

@@ -23,6 +23,10 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
+#if XE_PLATFORM_MAC
+#include <limits.h>
+#include <mach-o/dyld.h>
+#endif
 
 namespace xe {
 
@@ -43,10 +47,26 @@ std::filesystem::path to_path(const std::u16string_view source) {
 namespace filesystem {
 
 std::filesystem::path GetExecutablePath() {
+#if XE_PLATFORM_MAC
+  char path[PATH_MAX];
+  uint32_t size = sizeof(path);
+  if (_NSGetExecutablePath(path, &size) == 0) {
+    char real_path[PATH_MAX];
+    if (realpath(path, real_path)) {
+      return std::string(real_path);
+    }
+    return std::string(path);
+  }
+  return std::string();
+#else
   char buff[FILENAME_MAX] = "";
-  readlink("/proc/self/exe", buff, FILENAME_MAX);
-  std::string s(buff);
-  return s;
+  ssize_t len = readlink("/proc/self/exe", buff, sizeof(buff) - 1);
+  if (len != -1) {
+    buff[len] = '\0';
+    return std::string(buff);
+  }
+  return std::string();
+#endif
 }
 
 std::filesystem::path GetExecutableFolder() {

src/xenia/base/memory_posix.cc

@@ -146,7 +146,9 @@ void* AllocFixed(void* base_address, size_t length,
       }
       return nullptr;
     }
+#ifdef MAP_FIXED_NOREPLACE
     flags |= MAP_FIXED_NOREPLACE;
+#endif
   }
 
   void* result = mmap(base_address, length, prot, flags, -1, 0);
@@ -296,7 +298,7 @@ FileMappingHandle CreateFileMappingHandle(const std::filesystem::path& path,
   if (ret < 0) {
     return kFileMappingHandleInvalid;
   }
-  if (ftruncate64(ret, length) < 0) {
+  if (ftruncate(ret, length) < 0) {
     close(ret);
     shm_unlink(full_path.c_str());
     return kFileMappingHandleInvalid;
@@ -335,7 +337,9 @@ void* MapFileView(FileMappingHandle handle, void* base_address, size_t length,
 
   int flags = MAP_SHARED;
   if (base_address != nullptr) {
+#ifdef MAP_FIXED_NOREPLACE
     flags |= MAP_FIXED_NOREPLACE;
+#endif
   }
 
   void* result = mmap(base_address, length, prot, flags, handle, file_offset);

src/xenia/gpu/null/CMakeLists.txt

@@ -1,7 +1,11 @@
 add_library(xenia-gpu-null STATIC)
 xe_platform_sources(xenia-gpu-null ${CMAKE_CURRENT_SOURCE_DIR})
-target_include_directories(xenia-gpu-null PRIVATE
-  ${PROJECT_SOURCE_DIR}/third_party/Vulkan-Headers/include
-)
-target_link_libraries(xenia-gpu-null PUBLIC xenia-base xenia-gpu xenia-ui xenia-ui-vulkan xxhash)
+if(APPLE)
+  target_link_libraries(xenia-gpu-null PUBLIC xenia-base xenia-gpu xenia-ui xxhash)
+else()
+  target_include_directories(xenia-gpu-null PRIVATE
+    ${PROJECT_SOURCE_DIR}/third_party/Vulkan-Headers/include
+  )
+  target_link_libraries(xenia-gpu-null PUBLIC xenia-base xenia-gpu xenia-ui xenia-ui-vulkan xxhash)
+endif()
 xe_target_defaults(xenia-gpu-null)

src/xenia/gpu/null/null_graphics_system.cc

@@ -10,7 +10,9 @@
 #include "xenia/gpu/null/null_graphics_system.h"
 
 #include "xenia/gpu/null//null_command_processor.h"
+#if !XE_PLATFORM_MAC
 #include "xenia/ui/vulkan/vulkan_provider.h"
+#endif
 #include "xenia/xbox.h"
 
 namespace xe {
@@ -25,9 +27,13 @@ X_STATUS NullGraphicsSystem::Setup(cpu::Processor* processor,
                                    kernel::KernelState* kernel_state,
                                    ui::WindowedAppContext* app_context,
                                    bool with_presentation) {
+#if XE_PLATFORM_MAC
+  provider_ = nullptr;
+#else
   // This is a null graphics system, but we still setup vulkan because UI needs
   // it through us :|
   provider_ = xe::ui::vulkan::VulkanProvider::Create(false, with_presentation);
+#endif
   return GraphicsSystem::Setup(processor, kernel_state, app_context,
                                with_presentation);
 }

third_party/CMakeLists.txt

@@ -121,6 +121,12 @@ if(WIN32)
     discord-rpc/src/connection_win.cpp
     discord-rpc/src/discord_register_win.cpp
   )
+elseif(APPLE)
+  target_sources(discord-rpc PRIVATE
+    discord-rpc/src/connection_unix.cpp
+    discord-rpc/src/discord_register_osx.m
+  )
+  target_link_libraries(discord-rpc PRIVATE "-framework AppKit")
 elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
   target_sources(discord-rpc PRIVATE
     discord-rpc/src/connection_unix.cpp