--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/python3.8/site-packages/pip/_vendor/pep517/build.py	Mon Jul 27 03:47:31 2020 -0400
@@ -0,0 +1,124 @@
+"""Build a project using PEP 517 hooks.
+"""
+import argparse
+import logging
+import os
+import toml
+import shutil
+
+from .envbuild import BuildEnvironment
+from .wrappers import Pep517HookCaller
+from .dirtools import tempdir, mkdir_p
+from .compat import FileNotFoundError
+
+log = logging.getLogger(__name__)
+
+
+def validate_system(system):
+    """
+    Ensure build system has the requisite fields.
+    """
+    required = {'requires', 'build-backend'}
+    if not (required <= set(system)):
+        message = "Missing required fields: {missing}".format(
+            missing=required-set(system),
+        )
+        raise ValueError(message)
+
+
+def load_system(source_dir):
+    """
+    Load the build system from a source dir (pyproject.toml).
+    """
+    pyproject = os.path.join(source_dir, 'pyproject.toml')
+    with open(pyproject) as f:
+        pyproject_data = toml.load(f)
+    return pyproject_data['build-system']
+
+
+def compat_system(source_dir):
+    """
+    Given a source dir, attempt to get a build system backend
+    and requirements from pyproject.toml. Fallback to
+    setuptools but only if the file was not found or a build
+    system was not indicated.
+    """
+    try:
+        system = load_system(source_dir)
+    except (FileNotFoundError, KeyError):
+        system = {}
+    system.setdefault(
+        'build-backend',
+        'setuptools.build_meta:__legacy__',
+    )
+    system.setdefault('requires', ['setuptools', 'wheel'])
+    return system
+
+
+def _do_build(hooks, env, dist, dest):
+    get_requires_name = 'get_requires_for_build_{dist}'.format(**locals())
+    get_requires = getattr(hooks, get_requires_name)
+    reqs = get_requires({})
+    log.info('Got build requires: %s', reqs)
+
+    env.pip_install(reqs)
+    log.info('Installed dynamic build dependencies')
+
+    with tempdir() as td:
+        log.info('Trying to build %s in %s', dist, td)
+        build_name = 'build_{dist}'.format(**locals())
+        build = getattr(hooks, build_name)
+        filename = build(td, {})
+        source = os.path.join(td, filename)
+        shutil.move(source, os.path.join(dest, os.path.basename(filename)))
+
+
+def build(source_dir, dist, dest=None, system=None):
+    system = system or load_system(source_dir)
+    dest = os.path.join(source_dir, dest or 'dist')
+    mkdir_p(dest)
+
+    validate_system(system)
+    hooks = Pep517HookCaller(
+        source_dir, system['build-backend'], system.get('backend-path')
+    )
+
+    with BuildEnvironment() as env:
+        env.pip_install(system['requires'])
+        _do_build(hooks, env, dist, dest)
+
+
+parser = argparse.ArgumentParser()
+parser.add_argument(
+    'source_dir',
+    help="A directory containing pyproject.toml",
+)
+parser.add_argument(
+    '--binary', '-b',
+    action='store_true',
+    default=False,
+)
+parser.add_argument(
+    '--source', '-s',
+    action='store_true',
+    default=False,
+)
+parser.add_argument(
+    '--out-dir', '-o',
+    help="Destination in which to save the builds relative to source dir",
+)
+
+
+def main(args):
+    # determine which dists to build
+    dists = list(filter(None, (
+        'sdist' if args.source or not args.binary else None,
+        'wheel' if args.binary or not args.source else None,
+    )))
+
+    for dist in dists:
+        build(args.source_dir, dist, args.out_dir)
+
+
+if __name__ == '__main__':
+    main(parser.parse_args())