# Adapted with modifications from tensorflow/third_party/py/
"""Repository rule for Python autoconfiguration.
`python_configure` depends on the following environment variables:
* `PYTHON_BIN_PATH`: location of python binary.
* `PYTHON_LIB_PATH`: Location of python libraries.
"""
_BAZEL_SH = "BAZEL_SH"
_PYTHON_BIN_PATH = "PYTHON_BIN_PATH"
_PYTHON_LIB_PATH = "PYTHON_LIB_PATH"
_PYTHON_CONFIG_REPO = "PYTHON_CONFIG_REPO"
def _tpl(repository_ctx, tpl, substitutions={}, out=None):
if not out:
out = tpl
repository_ctx.template(out, Label("//third_party/py:%s.tpl" % tpl),
substitutions)
def _fail(msg):
"""Output failure message when auto configuration fails."""
red = "\033[0;31m"
no_color = "\033[0m"
fail("%sPython Configuration Error:%s %s\n" % (red, no_color, msg))
def _is_windows(repository_ctx):
"""Returns true if the host operating system is windows."""
os_name = repository_ctx.os.name.lower()
return os_name.find("windows") != -1
def _execute(repository_ctx,
cmdline,
error_msg=None,
error_details=None,
empty_stdout_fine=False):
"""Executes an arbitrary shell command.
Args:
repository_ctx: the repository_ctx object
cmdline: list of strings, the command to execute
error_msg: string, a summary of the error if the command fails
error_details: string, details about the error or steps to fix it
empty_stdout_fine: bool, if True, an empty stdout result is fine, otherwise
it's an error
Return:
the result of repository_ctx.execute(cmdline)
"""
result = repository_ctx.execute(cmdline)
if result.stderr or not (empty_stdout_fine or result.stdout):
_fail("\n".join([
error_msg.strip() if error_msg else "Repository command failed",
result.stderr.strip(), error_details if error_details else ""
]))
else:
return result
def _read_dir(repository_ctx, src_dir):
"""Returns a string with all files in a directory.
Finds all files inside a directory, traversing subfolders and following
symlinks. The returned string contains the full path of all files
separated by line breaks.
"""
if _is_windows(repository_ctx):
src_dir = src_dir.replace("/", "\\")
find_result = _execute(
repository_ctx,
["cmd.exe", "/c", "dir", src_dir, "/b", "/s", "/a-d"],
empty_stdout_fine=True)
# src_files will be used in genrule.outs where the paths must
# use forward slashes.
return find_result.stdout.replace("\\", "/")
else:
find_result = _execute(
repository_ctx, ["find", src_dir, "-follow", "-type", "f"],
empty_stdout_fine=True)
return find_result.stdout
def _genrule(src_dir, genrule_name, command, outs):
"""Returns a string with a genrule.
Genrule executes the given command and produces the given outputs.
"""
return ('genrule(\n' + ' name = "' + genrule_name + '",\n' +
' outs = [\n' + outs + '\n ],\n' + ' cmd = """\n' +
command + '\n """,\n' + ')\n')
def _normalize_path(path):
"""Returns a path with '/' and remove the trailing slash."""
path = path.replace("\\", "/")
if path[-1] == "/":
path = path[:-1]
return path
def _symlink_genrule_for_dir(repository_ctx,
src_dir,
dest_dir,
genrule_name,
src_files=[],
dest_files=[]):
"""Returns a genrule to symlink(or copy if on Windows) a set of files.
If src_dir is passed, files will be read from the given directory; otherwise
we assume files are in src_files and dest_files
"""
if src_dir != None:
src_dir = _normalize_path(src_dir)
dest_dir = _normalize_path(dest_dir)
files = '\n'.join(
sorted(_read_dir(repository_ctx, src_dir).splitlines()))
# Create a list with the src_dir stripped to use for outputs.
dest_files = files.replace(src_dir, '').splitlines()
src_files = files.splitlines()
command = []
outs = []
for i in range(len(dest_files)):
if dest_files[i] != "":
# If we have only one file to link we do not want to use the dest_dir, as
# $(@D) will include the full path to the file.
dest = '$(@D)/' + dest_dir + dest_files[i] if len(
dest_files) != 1 else '$(@D)/' + dest_files[i]
# On Windows, symlink is not supported, so we just copy all the files.
cmd = 'cp -f' if _is_windows(repository_ctx) else 'ln -s'
command.append(cmd + ' "%s" "%s"' % (src_files[i], dest))
outs.append(' "' + dest_dir + dest_files[i] + '",')
return _genrule(src_dir, genrule_name, " && ".join(command),
"\n".join(outs))
def _get_python_bin(repository_ctx):
"""Gets the python bin path."""
python_bin = repository_ctx.os.environ.get(_PYTHON_BIN_PATH)
if python_bin != None:
return python_bin
python_bin_path = repository_ctx.which("python")
if python_bin_path != None:
return str(python_bin_path)
_fail("Cannot find python in PATH, please make sure " +
"python is installed and add its directory in PATH, or --define " +
"%s='/something/else'.\nPATH=%s" %
(_PYTHON_BIN_PATH, repository_ctx.os.environ.get("PATH", "")))
def _get_bash_bin(repository_ctx):
"""Gets the bash bin path."""
bash_bin = repository_ctx.os.environ.get(_BAZEL_SH)
if bash_bin != None:
return bash_bin
else:
bash_bin_path = repository_ctx.which("bash")
if bash_bin_path != None:
return str(bash_bin_path)
else:
_fail(
"Cannot find bash in PATH, please make sure " +
"bash is installed and add its directory in PATH, or --define "
+ "%s='/path/to/bash'.\nPATH=%s" %
(_BAZEL_SH, repository_ctx.os.environ.get("PATH", "")))
def _get_python_lib(repository_ctx, python_bin):
"""Gets the python lib path."""
python_lib = repository_ctx.os.environ.get(_PYTHON_LIB_PATH)
if python_lib != None:
return python_lib
print_lib = (
"<<END\n" + "from __future__ import print_function\n" +
"import site\n" + "import os\n" + "\n" + "try:\n" +
" input = raw_input\n" + "except NameError:\n" + " pass\n" + "\n" +
"python_paths = []\n" + "if os.getenv('PYTHONPATH') is not None:\n" +
" python_paths = os.getenv('PYTHONPATH').split(':')\n" + "try:\n" +
" library_paths = site.getsitepackages()\n" +
"except AttributeError:\n" +
" from distutils.sysconfig import get_python_lib\n" +
" library_paths = [get_python_lib()]\n" +
"all_paths = set(python_paths + library_paths)\n" + "paths = []\n" +
"for path in all_paths:\n" + " if os.path.isdir(path):\n" +
" paths.append(path)\n" + "if len(paths) >=1:\n" +
" print(paths[0])\n" + "END")
cmd = '%s - %s' % (python_bin, print_lib)
result = repository_ctx.execute([_get_bash_bin(repository_ctx), "-c", cmd])
return result.stdout.strip('\n')
def _check_python_lib(repository_ctx, python_lib):
"""Checks the python lib path."""
cmd = 'test -d "%s" -a -x "%s"' % (python_lib, python_lib)
result = repository_ctx.execute([_get_bash_bin(repository_ctx), "-c", cmd])
if result.return_code == 1:
_fail("Invalid python library path: %s" % python_lib)
def _check_python_bin(repository_ctx, python_bin):
"""Checks the python bin path."""
cmd = '[[ -x "%s" ]] && [[ ! -d "%s" ]]' % (python_bin, python_bin)
result = repository_ctx.execute([_get_bash_bin(repository_ctx), "-c", cmd])
if result.return_code == 1:
_fail("--define %s='%s' is not executable. Is it the python binary?" %
(_PYTHON_BIN_PATH, python_bin))
def _get_python_include(repository_ctx, python_bin):
"""Gets the python include path."""
result = _execute(
repository_ctx, [
python_bin, "-c", 'from __future__ import print_function;' +
'from distutils import sysconfig;' +
'print(sysconfig.get_python_inc())'
],
error_msg="Problem getting python include path.",
error_details=(
"Is the Python binary path set up right? " + "(See ./configure or "
+ _PYTHON_BIN_PATH + ".) " + "Is distutils installed?"))
return result.stdout.splitlines()[0]
def _get_python_import_lib_name(repository_ctx, python_bin):
"""Get Python import library name (pythonXY.lib) on Windows."""
result = _execute(
repository_ctx, [
python_bin, "-c",
'import sys;' + 'print("python" + str(sys.version_info[0]) + ' +
' str(sys.version_info[1]) + ".lib")'
],
error_msg="Problem getting python import library.",
error_details=("Is the Python binary path set up right? " +
"(See ./configure or " + _PYTHON_BIN_PATH + ".) "))
return result.stdout.splitlines()[0]
def _create_local_python_repository(repository_ctx):
"""Creates the repository containing files set up to build with Python."""
python_bin = _get_python_bin(repository_ctx)
_check_python_bin(repository_ctx, python_bin)
python_lib = _get_python_lib(repository_ctx, python_bin)
_check_python_lib(repository_ctx, python_lib)
python_include = _get_python_include(repository_ctx, python_bin)
python_include_rule = _symlink_genrule_for_dir(
repository_ctx, python_include, 'python_include', 'python_include')
python_import_lib_genrule = ""
# To build Python C/C++ extension on Windows, we need to link to python import library pythonXY.lib
# See https://docs.python.org/3/extending/windows.html
if _is_windows(repository_ctx):
python_include = _normalize_path(python_include)
python_import_lib_name = _get_python_import_lib_name(
repository_ctx, python_bin)
python_import_lib_src = python_include.rsplit(
'/', 1)[0] + "/libs/" + python_import_lib_name
python_import_lib_genrule = _symlink_genrule_for_dir(
repository_ctx, None, '', 'python_import_lib',
[python_import_lib_src], [python_import_lib_name])
_tpl(
repository_ctx, "BUILD", {
"%{PYTHON_INCLUDE_GENRULE}": python_include_rule,
"%{PYTHON_IMPORT_LIB_GENRULE}": python_import_lib_genrule,
})
def _create_remote_python_repository(repository_ctx, remote_config_repo):
"""Creates pointers to a remotely configured repo set up to build with Python.
"""
_tpl(repository_ctx, "remote.BUILD", {
"%{REMOTE_PYTHON_REPO}": remote_config_repo,
}, "BUILD")
def _python_autoconf_impl(repository_ctx):
"""Implementation of the python_autoconf repository rule."""
if _PYTHON_CONFIG_REPO in repository_ctx.os.environ:
_create_remote_python_repository(
repository_ctx, repository_ctx.os.environ[_PYTHON_CONFIG_REPO])
else:
_create_local_python_repository(repository_ctx)
python_configure = repository_rule(
implementation=_python_autoconf_impl,
environ=[
_BAZEL_SH,
_PYTHON_BIN_PATH,
_PYTHON_LIB_PATH,
_PYTHON_CONFIG_REPO,
],
)
"""Detects and configures the local Python.
Add the following to your WORKSPACE FILE:
```python
python_configure(name = "local_config_python")
```
Args:
name: A unique name for this workspace rule.
"""