# Copyright 2019 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import("//build/components.gni")
import("//build/dist/resource.gni")
import("//build/sdk/sdk_atom.gni")
import("//build/testing/host_test_data.gni")
import("//src/lib/vulkan/build/config.gni")
import("//src/lib/vulkan/layers.gni")

# Centralizing the GN points of entry into Vulkan ecosystem repositories here is helpful
# for grasping the full scope.  Note, there are also entry points in //sdk/BUILD.gn.

# Provides the Vulkan headers and entry points via the Vulkan loader.
group("vulkan") {
  public_configs = [ ":vulkan_hpp" ]

  # Targets always use in-tree Vulkan implementation.
  if (!is_host) {
    public_deps = [
      ":headers",
      "//third_party/Vulkan-Loader:libvulkan",
    ]
  }

  # Host target with "null" Vulkan should use Vulkan headers and
  # link the null Vulkan implementation statically.
  if (is_host && use_null_vulkan_on_host) {
    public_deps = [
      ":headers",
      "//src/lib/vulkan/third_party/null_vulkan",
    ]
  }

  # Host target with non-null Vulkan should link against prebuilt
  # Vulkan SDK.
  if (is_host && !use_null_vulkan_on_host) {
    public_deps = [
      ":copy_vulkan_runtime",
      ":headers",
      ":vulkan_host_loader",
    ]
  }
}

group("vulkan_headers_and_loader") {
  public_deps = [
    ":headers",
    "//third_party/Vulkan-Loader:libvulkan",
  ]
}

# Provides only the Vulkan headers without the loader.
group("headers") {
  public_deps = [ "//third_party/Vulkan-Headers:vulkan_headers" ]
}

group("tests") {
  testonly = true
  deps = [
    ":loader_and_validation_tests",
    "tests",
  ]

  # Ensure loader builds for Linux x64
  deps += [ ":vulkan_headers_and_loader(//build/toolchain:linux_x64-shared)" ]
}

# Tests for the Vulkan loader and validation layers.
group("loader_and_validation_tests") {
  testonly = true
  public_deps = [
    "//third_party/Vulkan-Loader:tests",
    "//third_party/Vulkan-ValidationLayers:tests",
  ]
}

# The vulkaninfo application.
group("vulkaninfo") {
  public_deps = [ "//third_party/Vulkan-Tools:vulkaninfo" ]
}

config("vulkan_hpp") {
  defines = [ "VULKAN_HPP_NO_EXCEPTIONS" ]
  if (is_debug) {
    defines += [ "VULKAN_HPP_ASSERT(expr)=((void)(expr))" ]
  } else {
    defines += [ "VULKAN_HPP_ASSERT(expr)=do {} while(0)" ]
  }
}

import("//src/lib/vulkan/swapchain/sdk_atom_info.gni")
import("//src/lib/vulkan/validation_layers/sdk_atom_info.gni")

# A list of scopes describing the Vulkan layers to add to the SDK.
# Each item is a scope describing a given layer, which consists
# in a loadable module and a JSON configuration file.
#
# The expected schema is the following:
#
#   module_name (optional)
#     [string] Name of the loadable module (e.g. 'VkLayer_khrnos_validation.so).
#     If not specified, then 'module_file' is required and will be used to
#     determine the name.
#
#   module_label (required)
#     [GN label] Label of the target generating the module, if it is not a
#     prebuilt one.
#
#   module_file (optional)
#     [GN path] Path to the loadable module. Required if 'module_name' is not
#     defined. Otherwise, if 'module_label' is defined, this defaults to
#     '$root_out_dir/$module_name'.
#
#   config_name (optional)
#     [string] Name of the configuration file (e.g. 'VkLayer_khronos_validation.json').
#     If not specified, then 'config_file' is required and will be used to
#     determine the name.
#
#   config_label (optional)
#     [GN label] Label of the target generating the config file, if it is not
#     a prebuilt one.
#
#   config_file (required)
#     [GN path] Path to the configuration file.
#
vulkan_layers_sdk_atom_infos = vulkan_validation_layers_sdk_atom_infos
vulkan_layers_sdk_atom_infos += [ vulkan_image_pipe_swapchain_sdk_atom_info ]

sdk_atom("vulkan_layers") {
  id = "sdk://pkg/vulkan_layers"

  category = "partner"

  files = []
  non_sdk_deps = []

  _sdk_binaries = []
  _sdk_resources = []

  foreach(info, vulkan_layers_sdk_atom_infos) {
    # Add loadable module to metadata and file list
    if (defined(info.module_name)) {
      _module_name = info.module_name
    } else {
      assert(defined(info.module_file),
             "module_file is required if module_name is not defined: $info")
      _module_name = get_path_info(info.module_file, "file")
    }
    if (defined(info.module_file)) {
      _module_file = info.module_file
    } else {
      assert(defined(info.module_name),
             "module_name is required if module_file is not defined: $info")
      _module_file = "$root_out_dir/${_module_name}"
    }

    base = "arch/$target_cpu"
    _destination = "${base}/dist/" + _module_name

    _sdk_binaries += [ _destination ]
    files += [
      {
        source = _module_file
        dest = _destination
      },
    ]
    if (defined(info.module_label)) {
      non_sdk_deps += [ info.module_label ]
    }

    # Add config file to metadata and file list
    if (defined(info.config_name)) {
      _config_name = info.config_name
    } else {
      assert(defined(info.config_file),
             "config_file is required if config_name is not defined: $info")
      _config_name = get_path_info(info.config_file, "file")
    }
    assert(defined(info.config_file), "config_file is required: $info")
    _config_file = info.config_file
    _destination =
        "pkg/vulkan_layers/data/vulkan/explicit_layer.d/${_config_name}"
    _sdk_resources += [ _destination ]
    files += [
      {
        source = _config_file
        dest = _destination
      },
    ]
    if (defined(info.config_label)) {
      non_sdk_deps += [ info.config_label ]
    }
  }

  meta = {
    dest = "pkg/vulkan_layers/meta.json"
    schema = "loadable_module"
    value = {
      type = "loadable_module"
      name = "vulkan_layers"
      root = "pkg/vulkan_layers"
      resources = []
      resources = _sdk_resources
      binaries = {
      }
      if (target_cpu == "arm64") {
        binaries.arm64 = _sdk_binaries
      } else if (target_cpu == "x64") {
        binaries.x64 = _sdk_binaries
      } else if (target_cpu == "riscv64") {
        binaries.riscv64 = _sdk_binaries
      } else {
        assert(false, "Unknown CPU type: %target_cpu")
      }
    }
  }
}

#
# Copy Vulkan runtime (loader, validation layers library and layers descriptor)
# to test_data directory.
#
if (is_host && current_cpu == "x64") {
  copy("copy_vulkan_libs") {
    assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
    _lib_dir = vulkan_host_runtime_sub_dirs.lib
    if (is_linux) {
      sources = [
        "$vulkan_host_runtime_dir/$_lib_dir/libVkLayer_khronos_validation.so",
        "$vulkan_host_runtime_dir/$_lib_dir/libvulkan.so.1",
      ]
      if (use_swiftshader_vulkan_icd_on_host) {
        sources += [
          "$vulkan_host_runtime_dir/$_lib_dir/libvk_swiftshader.so",
          "$vulkan_host_runtime_dir/$_lib_dir/vk_swiftshader_icd.json",
        ]
      }
    }
    if (is_mac) {
      sources = [
        "$vulkan_host_runtime_dir/$_lib_dir/MoltenVK_icd.json",
        "$vulkan_host_runtime_dir/$_lib_dir/libMoltenVK.dylib",
        "$vulkan_host_runtime_dir/$_lib_dir/libVkLayer_khronos_validation.dylib",

        # Note also libvulkan.1.dylib below which has to be treated specially
        # because of its symlink to libvulkan.dylib.
      ]
      if (use_swiftshader_vulkan_icd_on_host) {
        sources += [
          "$vulkan_host_runtime_dir/$_lib_dir/libvk_swiftshader.dylib",
          "$vulkan_host_runtime_dir/$_lib_dir/vk_swiftshader_icd.json",
        ]
      }
    }
    outputs = [ "${root_out_dir}/${vulkan_host_runtime_out_root}/${_lib_dir}/{{source_file_part}}" ]
  }

  # On Linux, libvulkan.so is a symbolic link to libvulkan.so.1. For symbolic
  # links, ninja records the modification time of the linked file into its log,
  # so we need to ensure that the original library file is copied before the
  # symbolic link. We do this by adding "copy_vulkan_libs" as its dependency.
  if (is_linux) {
    copy("vulkan_lib_links") {
      assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
      _lib_dir = vulkan_host_runtime_sub_dirs.lib
      sources = [ "$vulkan_host_runtime_dir/$_lib_dir/libvulkan.so" ]
      outputs = [ "${root_out_dir}/${vulkan_host_runtime_out_root}/${_lib_dir}/{{source_file_part}}" ]
      deps = [ ":copy_vulkan_libs" ]
    }
  }

  # On macOS, copy target will makes copies of all symlinks instead of keeping
  # the links. Having two separated libvulkan.1.dylib and libvulkan.dylib will
  # cause Vulkan loader crash, thus we set the symlink after the actual dylib
  # libvulkan.dylib is copied to build out directory. Additionally, because
  # ninja looks at the timestamp of the linked-to target, and a copy() will
  # hardlink, we do a real copy here of libvulkan.1.dylib to update its
  # timestamp before softlinking, otherwise the timestamp of the link (an
  # output of this rule) will never be newer than the .stamp file, so this rule
  # will always be dirty. https://fxbug.dev/42144619.
  if (is_mac) {
    action("vulkan_lib_links") {
      assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
      script = "//src/lib/vulkan/build/copy_and_symlink.py"
      _lib_dir = vulkan_host_runtime_sub_dirs.lib
      sources = [ "$vulkan_host_runtime_dir/$_lib_dir/libvulkan.1.dylib" ]
      outputs = [
        "${root_out_dir}/${vulkan_host_runtime_out_root}/${_lib_dir}/libvulkan.1.dylib",
        "${root_out_dir}/${vulkan_host_runtime_out_root}/${_lib_dir}/libvulkan.dylib",
      ]
      args = [
        rebase_path(sources[0], root_build_dir),  # source.
        rebase_path(outputs[0], root_build_dir),  # copy_to.
        rebase_path(outputs[1], root_build_dir),  # link_to.
      ]
      deps = [ ":copy_vulkan_libs" ]
    }
  }

  copy("copy_vulkan_etc") {
    assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
    _layers_dir = vulkan_host_runtime_sub_dirs.layers
    sources = [
      "$vulkan_host_runtime_dir/$_layers_dir/VkLayer_khronos_validation.json",
    ]
    outputs = [ "${root_out_dir}/${vulkan_host_runtime_out_root}/${_layers_dir}/{{source_file_part}}" ]
  }

  host_test_data("vulkan_test_data") {
    assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
    _lib_dir = vulkan_host_runtime_sub_dirs.lib
    _layers_dir = vulkan_host_runtime_sub_dirs.layers
    _data_dir = "${root_out_dir}/${vulkan_host_runtime_out_root}"
    sources = [
      "${_data_dir}/${_layers_dir}",
      "${_data_dir}/${_lib_dir}",
    ]
    deps = [
      ":copy_vulkan_etc",
      ":copy_vulkan_libs",
      ":vulkan_lib_links",
    ]
  }

  group("copy_vulkan_runtime") {
    assert(has_prebuilt_vulkan_runtime, "Prebuilt Vulkan runtime not found.")
    deps = [
      ":copy_vulkan_etc",
      ":copy_vulkan_libs",
      ":vulkan_lib_links",
    ]
  }
}

#
# Vulkan dependencies required for Vulkan executables / tests / source sets.
# This includes headers, loader linkage, and copying of runtime files for host
# executables.
#
config("vulkan_host_loader_config") {
  if (current_cpu == "x64" && is_host) {
    # Use the runtime libs instead of the downloaded SDK libs to avoid linking issues.
    # The SDK libs may have dependencies on newer C library symbols (for example from SDK 1.3.268:
    # ld.lld: error: undefined reference due to --no-allow-shlib-undefined: pow@GLIBC_2.29
    # >>> referenced by ../../prebuilt/third_party/vulkansdk/linux/x86_64/lib/libvulkan.so
    #)
    _lib_dir = vulkan_host_runtime_sub_dirs.lib
    lib_dirs = [ "$vulkan_host_runtime_dir/$_lib_dir" ]

    # Link Vulkan loader to host executables.
    libs = [ "vulkan" ]
  }
}

group("vulkan_host_loader") {
  public_configs = [ ":vulkan_host_loader_config" ]
}

group("vulkan_validation_layers") {
  deps = [
    ":vklayer_khronos_validation_json",
    "//third_party/Vulkan-ValidationLayers:vulkan_validation_layers",
  ]
}

resource("vklayer_khronos_validation_json") {
  sources = [ "$vulkan_data_dir/VkLayer_khronos_validation.json" ]
  outputs = [ "data/vulkan/explicit_layer.d/VkLayer_khronos_validation.json" ]
  deps = [ "//third_party/Vulkan-ValidationLayers:vulkan_gen_json_files" ]
}