1#!/usr/bin/env python
2
3import os
4import re
5import tempfile
6import shutil
7import sys
8import subprocess
9import zipfile
10
11PYTHON_BINARY = '%interpreter%'
12MAIN_FILE = '%main%'
13PYTHON_PATH = 'PYTHONPATH'
14
15# Don't imply 'import site' on initialization
16PYTHON_ARG = '-S'
17
18def SearchPathEnv(name):
19  search_path = os.getenv('PATH', os.defpath).split(os.pathsep)
20  for directory in search_path:
21    if directory == '': continue
22    path = os.path.join(directory, name)
23    # Check if path is actual executable file.
24    if os.path.isfile(path) and os.access(path, os.X_OK):
25      return path
26  return None
27
28def FindPythonBinary():
29  if PYTHON_BINARY.startswith('/'):
30    # Case 1: Python interpreter is directly provided with absolute path.
31    return PYTHON_BINARY
32  else:
33    # Case 2: Find Python interpreter through environment variable: PATH.
34    return SearchPathEnv(PYTHON_BINARY)
35
36# Create the runfiles tree by extracting the zip file
37def ExtractRunfiles():
38  temp_dir = tempfile.mkdtemp("", "Soong.python_")
39  zf = zipfile.ZipFile(os.path.dirname(__file__))
40  zf.extractall(temp_dir)
41  return temp_dir
42
43def Main():
44  args = sys.argv[1:]
45
46  new_env = {}
47  runfiles_path = None
48
49  try:
50    runfiles_path = ExtractRunfiles()
51
52    # Add runfiles path to PYTHONPATH.
53    python_path_entries = [runfiles_path]
54
55    # Add top dirs within runfiles path to PYTHONPATH.
56    top_entries = [os.path.join(runfiles_path, i) for i in os.listdir(runfiles_path)]
57    top_pkg_dirs = [i for i in top_entries if os.path.isdir(i)]
58    python_path_entries += top_pkg_dirs
59
60    old_python_path = os.environ.get(PYTHON_PATH)
61    separator = ':'
62    new_python_path = separator.join(python_path_entries)
63
64    # Copy old PYTHONPATH.
65    if old_python_path:
66      new_python_path += separator + old_python_path
67    new_env[PYTHON_PATH] = new_python_path
68
69    # Now look for main python source file.
70    main_filepath = os.path.join(runfiles_path, MAIN_FILE)
71    assert os.path.exists(main_filepath), \
72           'Cannot exec() %r: file not found.' % main_filepath
73    assert os.access(main_filepath, os.R_OK), \
74           'Cannot exec() %r: file not readable.' % main_filepath
75
76    python_program = FindPythonBinary()
77    if python_program is None:
78      raise AssertionError('Could not find python binary: ' + PYTHON_BINARY)
79    args = [python_program, PYTHON_ARG, main_filepath] + args
80
81    os.environ.update(new_env)
82
83    sys.stdout.flush()
84    retCode = subprocess.call(args)
85    exit(retCode)
86  except:
87    raise
88  finally:
89    if runfiles_path is not None:
90      shutil.rmtree(runfiles_path, True)
91
92if __name__ == '__main__':
93  Main()
94