aboutsummaryrefslogtreecommitdiffhomepage
path: root/src/main/java/com/google/devtools/build/lib/bazel/rules/python/stub_template.txt
blob: 04316fea4d834f7f9d8fe9b5cf932d46e3c9c619 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
#!/usr/bin/env python

import os
import re
import tempfile
import shutil
import sys
import subprocess
import zipfile

# Return True if running on Windows
def IsWindows():
  return os.name == 'nt'

PYTHON_BINARY = '%python_binary%'
if IsWindows() and not PYTHON_BINARY.endswith('.exe'):
  PYTHON_BINARY = PYTHON_BINARY + '.exe'

# Find a file in a given search path.
def SearchPath(name):
  search_path = os.getenv('PATH', os.defpath).split(os.pathsep)
  for directory in search_path:
    if directory == '': continue
    path = os.path.join(directory, name)
    if os.path.isfile(path) and os.access(path, os.X_OK):
      return path
  return None

def IsRunningFromZip():
  return %is_zipfile%

# Find the real Python binary if it's not a normal absolute path
def FindPythonBinary():
  if PYTHON_BINARY.startswith('//'):
    # Case 1: Path is a label. Not supported yet.
    raise AssertionError(
      'Bazel does not support execution of Python interpreters via labels yet')
  elif PYTHON_BINARY.startswith('/'):
    # Case 2: Absolute path.
    return PYTHON_BINARY
  elif '/' in PYTHON_BINARY:
    # Case 3: Path is relative to current working directory.
    return os.path.join(os.getcwd(), PYTHON_BINARY)
  else:
    # Case 4: Path has to be looked up in the search path.
    return SearchPath(PYTHON_BINARY)

def CreatePythonPathEntries(python_imports, module_space):
  parts = python_imports.split(':');
  return [module_space] + ["%s/%s" % (module_space, path) for path in parts]

# Find the runfiles tree
def FindModuleSpace():
  # Follow symlinks, looking for my module space
  stub_filename = os.path.abspath(sys.argv[0])
  while True:
    # Found it?
    module_space = stub_filename + '.runfiles'
    if os.path.isdir(module_space):
      break

    runfiles_pattern = "(.*\.runfiles)/.*"
    if IsWindows():
      runfiles_pattern = "(.*\.runfiles)\\.*"
    matchobj = re.match(runfiles_pattern, os.path.abspath(sys.argv[0]))
    if matchobj:
      module_space = matchobj.group(1)
      break

    raise AssertionError('Cannot find .runfiles directory for %s' %
                         sys.argv[0])
  return module_space

# Create the runfiles tree by extracting the zip file
def CreateModuleSpace():
  ZIP_RUNFILES_DIRECTORY_NAME = "runfiles"
  temp_dir = tempfile.mkdtemp("", "Bazel.runfiles_")
  zf = zipfile.ZipFile(os.path.dirname(__file__))
  zf.extractall(temp_dir)
  return os.path.join(temp_dir, ZIP_RUNFILES_DIRECTORY_NAME)

def Main():
  args = sys.argv[1:]

  new_env = {}

  if IsRunningFromZip():
    module_space = CreateModuleSpace()
  else:
    module_space = FindModuleSpace()

  python_imports = '%imports%'
  python_path_entries = CreatePythonPathEntries(python_imports, module_space)

  repo_dirs = [os.path.join(module_space, d) for d in os.listdir(module_space)]
  repositories = [d for d in repo_dirs if os.path.isdir(d)]
  python_path_entries += repositories

  old_python_path = os.environ.get('PYTHONPATH')
  separator = ':'
  if IsWindows():
    separator = ';'
  python_path = separator.join(python_path_entries)
  if old_python_path:
    python_path += separator + old_python_path

  new_env['PYTHONPATH'] = python_path

  # Now look for my main python source file.
  # The magic string percent-main-percent is replaced with the filename of the
  # main file of the Python binary in BazelPythonSemantics.java.
  main_filename = os.path.join(module_space, '%main%')
  assert os.path.exists(main_filename), \
         'Cannot exec() %r: file not found.' % main_filename
  assert os.access(main_filename, os.R_OK), \
         'Cannot exec() %r: file not readable.' % main_filename

  program = python_program = FindPythonBinary()
  if python_program is None:
    raise AssertionError('Could not find python binary: ' + PYTHON_BINARY)
  args = [python_program, main_filename] + args

  os.environ.update(new_env)

  try:
    sys.stdout.flush()
    if IsRunningFromZip():
      retCode = subprocess.call(args)
      shutil.rmtree(os.path.dirname(module_space), True)
      exit(retCode)
    else:
      os.execv(args[0], args)
  except EnvironmentError as e:
    # This exception occurs when os.execv() fails for some reason.
    if not getattr(e, 'filename', None):
      e.filename = program  # Add info to error message
    raise

if __name__ == '__main__':
  Main()