Add the before_build script

Author: oscarbenjamin

bin/cibw_before_build_windows_arm64.py

@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+
+from __future__ import annotations
+
+import shlex
+import sys
+import sysconfig
+from pathlib import Path
+
+
+def _normalize_path(path: Path | str) -> str:
+    return str(path).replace('\\', '/')
+
+
+def _normalize_dll_name(name: str) -> str:
+    if name.endswith('.dll'):
+        return name
+    if name.startswith('lib') and name.endswith('.dll.a'):
+        return name[3:-2]
+    raise SystemExit(f'Unexpected Python library name: {name}')
+
+
+def _find_dll(dll_name: str) -> Path:
+    candidates: list[Path] = []
+    libdir = sysconfig.get_config_var('LIBDIR')
+    if libdir:
+        candidates.append(Path(libdir) / dll_name)
+    exe_dir = Path(sys.executable).resolve().parent
+    candidates.append(exe_dir / dll_name)
+    base_prefix = Path(getattr(sys, 'base_prefix', sys.prefix))
+    candidates.append(base_prefix / dll_name)
+    candidates.append(base_prefix / 'DLLs' / dll_name)
+    candidates.append(base_prefix / 'libs' / dll_name)
+
+    for candidate in candidates:
+        if candidate.exists():
+            return candidate.resolve()
+
+    paths = '\n'.join(_normalize_path(path) for path in candidates)
+    raise SystemExit(f'Could not find {dll_name} in:\n{paths}')
+
+
+def main() -> None:
+    repo_root = Path.cwd().resolve()
+    lib_dir = repo_root / '.local' / 'lib'
+    pkgconfig_dir = lib_dir / 'pkgconfig'
+    lib_dir.mkdir(parents=True, exist_ok=True)
+    pkgconfig_dir.mkdir(parents=True, exist_ok=True)
+
+    raw_name = sysconfig.get_config_var('DLLLIBRARY') or sysconfig.get_config_var('LDLIBRARY')
+    if not raw_name:
+        raise SystemExit('Could not determine Python DLL name')
+    dll_name = _normalize_dll_name(raw_name)
+    include_dir = sysconfig.get_config_var('INCLUDEPY')
+    if not include_dir:
+        raise SystemExit('Could not determine Python include dir')
+    pkg_version = sysconfig.get_config_var('LDVERSION') or sysconfig.get_python_version()
+    dll_path = _find_dll(dll_name)
+
+    values = {
+        'REPO_ROOT': _normalize_path(repo_root),
+        'LIB_DIR': _normalize_path(lib_dir),
+        'PKGCONFIG_DIR': _normalize_path(pkgconfig_dir),
+        'DLL_NAME': dll_name,
+        'DLL_PATH': _normalize_path(dll_path),
+        'PKG_VERSION': pkg_version,
+        'INCLUDE_DIR': _normalize_path(include_dir),
+    }
+
+    env_path = repo_root / '.local' / 'cibw_before_build_windows_arm64.env'
+    env_text = ''.join(f'{key}={shlex.quote(value)}\n' for key, value in values.items())
+    env_path.write_text(env_text, encoding='utf-8')
+    print(f'Generated {env_path}')
+
+
+if __name__ == '__main__':
+    main()