Add a PEP 517 compliant staging area to build

Resolves #12

ci/tools/poetry/hooks/build.py

@@ -0,0 +1,89 @@
+## @file
+# Copyright (c) 2023, The OCE Build Authors. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+##
+"""PEP-517 compliant build hook for poetry-core."""
+
+from functools import partial
+from os import listdir, makedirs, path
+from pathlib import Path
+from re import search as re_search, sub as re_sub, MULTILINE
+from shutil import copytree as _copytree, rmtree as _rmtree
+
+from typing import Tuple
+
+
+#NOTE: Keep in sync with ci/scripts/sort-imports.py
+RE_IMPORT_BLOCK = r'(?s)(\n*^(?:from|import).*^(?:from|import).*?\n*$)'
+"""Regular expression that matches import statements and adjacent newlines."""
+
+STAGING_PATH = 'ci/tools/poetry/staging'
+TARGET = f'{STAGING_PATH}/ocebuild'
+
+# Ensure that filesystem operations are graceful
+rmtree = partial(_rmtree, ignore_errors=True)
+copytree = partial(_copytree, dirs_exist_ok=True)
+
+def clean():
+ """Cleanup the staging directory."""
+ for target in filter(path.isdir, listdir(STAGING_PATH)):
+ target_path = f'{STAGING_PATH}/{target}'
+ rmtree(target_path)
+ makedirs(target_path, exist_ok=True)
+ open(f'{target_path}/__init__.py', 'w').close()
+
+def replace_module(module: str, replacement: str, string: str) -> str:
+ """Replace a module import with a new module import."""
+ pattern = r'\n(import|from)\s*' + module + r'\b'
+ repl = r'\n\1 ' + replacement
+
+ # Add a notice if the namespace is separated for clarity
+ notice = f"\n#NOTE: This import was remapped from '{module}' to '{replacement}'."
+ string = re_sub(r'\n' + pattern, r'\n' + notice + repl, string)
+
+ return re_sub(pattern, repl, string)
+
+def remap_module_imports(entrypoint: str, mappings: Tuple[str, str]) -> None:
+ """Recursively remap module imports in a package."""
+
+ for package in Path(entrypoint).glob('**/*.py'):
+ with open(package, 'r', encoding='UTF-8') as module_file:
+ file_text = module_file.read()
+
+ # Check if the file contains an imports block
+ imports_block = re_search(RE_IMPORT_BLOCK, file_text, flags=MULTILINE)
+ if imports_block:
+ imports_block = imports_block.group(0)
+ else: continue
+
+ with open(package, 'w', encoding='UTF-8') as module_file:
+ # Replace the imports block with the remapped imports
+ remapped_imports = imports_block
+ for module, replacement in mappings:
+ remapped_imports = replace_module(module, replacement, remapped_imports)
+
+ # Write the updated file back to disk
+ file_text = file_text.replace(imports_block, remapped_imports)
+ module_file.seek(0)
+ module_file.write(file_text)
+
+
+def pre_build():
+ clean()
+
+def post_build():
+ clean()
+ #TODO: Add post-build verification step
+ # e.g. inspecting the contents of the sdist/wheel archives:
+ # $ python3 -m tarfile -l dist/ocebuild-0.0.0.dev0.tar.gz
+ # $ python3 -m zipfile -l dist/ocebuild-0.0.0.dev0-cp311-cp311-macosx_13_0_x86_64.whl
+
+if __name__ == '__main__':
+ copytree('ocebuild', f'{STAGING_PATH}/ocebuild')
+ copytree('ocebuild_cli', f'{STAGING_PATH}/ocebuild/cli')
+ copytree('third_party', f'{STAGING_PATH}/ocebuild/third_party')
+
+ # Update module imports
+ remap_module_imports(f'{STAGING_PATH}/ocebuild',
+ mappings=(('ocebuild_cli', 'ocebuild.cli'),
+ ('third_party', 'ocebuild.third_party')))

ci/tools/poetry/staging/README.md

@@ -0,0 +1,9 @@
+# Staging
+
+This is the staging environment used by PEP-517 compliant builds of the project.
+Here, the project is restructured into a single `ocebuild` package scope where
+all module imports are rewritten to reflect the new root package scope.
+
+This leverages the `poetry-core` backend in the project's `pyproject.toml` and
+requires no additional configuration, ensuring that other PEP-517 frontends like
+PIP can also build the project from source.

ocebuild/cli/__main__.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python3
+
+## @file
+# Copyright (c) 2023, The OCE Build Authors. All rights reserved.
+# SPDX-License-Identifier: BSD-3-Clause
+##
+"""Stub entry point for the CLI."""
+
+from ocebuild_cli.__main__ import _main as _cli
+
+def _main():
+ _cli()
+
+if __name__ == '__main__':
+ _main()