Add build target "dependency_libomp".

build_system/targets/dependencies/macos/__init__.py

@@ -0,0 +1,16 @@
+"""
+Author: Michael Rapp (michael.rapp.ml@gmail.com)
+
+Defines targets and modules for compiling native library dependencies on macOS. This is necessary when building
+pre-built packages via "cibuildwheel", because the de facto package manager "homebrew" will install libraries that are
+compiled for the specific macOS version the build machine is running, instead of using the proper version for the target
+platform (see https://cibuildwheel.pypa.io/en/stable/faq/#missing-dependencies).
+"""
+from core.build_unit import BuildUnit
+from core.targets import PhonyTarget, TargetBuilder
+
+from targets.dependencies.macos.targets import compile_libomp
+
+TARGETS = TargetBuilder(BuildUnit.for_file(__file__)) \
+    .add_phony_target('dependency_libomp').set_functions(compile_libomp) \
+    .build()

build_system/targets/dependencies/macos/targets.py

@@ -0,0 +1,91 @@
+"""
+Author: Michael Rapp (michael.rapp.ml@gmail.com)
+
+Implements targets for compiling native library dependencies on macOS.
+"""
+import platform
+import shutil
+
+from os import path
+from typing import Tuple
+
+from core.build_unit import BuildUnit
+from util.io import create_directories
+from util.log import Log
+
+from targets.dependencies.macos.cmake import Cmake
+from targets.dependencies.macos.curl import CurlDownload
+from targets.dependencies.macos.tar import TarExtract
+from targets.dependencies.pygithub import GithubApi
+
+SUFFIX_SRC = '.src'
+
+SUFFIX_SRC_TAR_XZ = SUFFIX_SRC + '.tar.xz'
+
+
+def __get_download_url_and_file_name(github_api: GithubApi, package_name: str) -> Tuple[str, str]:
+    assets = github_api.open_repository('llvm/llvm-project').get_latest_release().get_assets()
+    prefix = package_name + '-'
+    download_asset = None
+
+    for asset in assets:
+        asset_name = asset.name
+
+        if asset_name.startswith(prefix) and asset_name.endswith(SUFFIX_SRC_TAR_XZ):
+            download_asset = asset
+            break
+
+    if not download_asset:
+        Log.error('Failed to identify asset to be downloaded!')
+
+    return download_asset.browser_download_url, download_asset.name
+
+
+def __download_package(github_api: GithubApi, package_name: str) -> str:
+    Log.info('Determining download URL of the latest release of package "%s"...', package_name)
+    download_url, file_name = __get_download_url_and_file_name(github_api, package_name=package_name)
+    Log.info('Downloading from "%s"...', download_url)
+    authorization_header = 'token ' + github_api.token if github_api.token else None
+    CurlDownload(download_url, authorization_header=authorization_header, file_name=file_name).run()
+    return file_name
+
+
+def __download_and_extract_package(github_api: GithubApi, package_name: str, extract_to: str) -> str:
+    file_name = __download_package(github_api, package_name=package_name)
+    file_name_without_suffix = file_name[:-len(SUFFIX_SRC_TAR_XZ)]
+    extract_directory = path.join(extract_to, file_name_without_suffix)
+    Log.info('Extracting file "%s" into directory "%s"...', file_name, extract_directory)
+    create_directories(extract_directory)
+    TarExtract(file_to_extract=file_name, into_directory=extract_directory).run()
+    return path.join(extract_directory, file_name_without_suffix + SUFFIX_SRC)
+
+
+def compile_libomp(build_unit: BuildUnit):
+    """
+    Compiles the dependency "libomp" (see https://github.com/Homebrew/homebrew-core/tree/master/Formula/lib/libomp.rb).
+    """
+    if platform.system().lower() != 'darwin':
+        Log.error('Target may only be run on macOS!')
+
+    github_api = GithubApi(build_unit).set_token_from_env()
+    build_directory = 'libomp'
+    cmake_directory = __download_and_extract_package(github_api, package_name='cmake', extract_to=build_directory)
+    openmp_directory = __download_and_extract_package(github_api, package_name='openmp', extract_to=build_directory)
+    shutil.copytree(path.join(cmake_directory, 'Modules'), path.join(openmp_directory, 'cmake'), dirs_exist_ok=True)
+
+    Log.info('Compiling from source directory "%s"...', openmp_directory)
+    args = [
+        '-DCMAKE_INSTALL_PREFIX=' + build_directory,
+        '-DCMAKE_INSTALL_LIBDIR=lib',
+        '-DCMAKE_BUILD_TYPE=Release',
+        '-DCMAKE_FIND_FRAMEWORK=LAST',
+        '-DCMAKE_VERBOSE_MAKEFILE=ON',
+        '-Wno-dev',
+        '-DBUILD_TESTING=OFF',
+        '-DLIBOMP_INSTALL_ALIASES=OFF',
+    ]
+    cmake_build_directory = path.join(build_directory, 'build', 'shared')
+    create_directories(cmake_build_directory)
+    Cmake('-S', openmp_directory, '-B', cmake_build_directory, *args).run()
+    Cmake('--build', cmake_build_directory).run()
+    Cmake('--install', cmake_build_directory).run()