blob: e289d9521cf370d3c5e3f9ead98cafbb30a05da1 [file] [log] [blame]
################################################################################
# DEPRECATION WARNING #
# #
# Direct access to @bazel_tools//tools/python, and to the native Python rules #
# and providers, is deprecated. All of these symbols are now accessible from #
# bazelbuild/rules_python. #
# #
# For native rules in particular, --incompatible_load_python_rules_from_bzl #
# (#9006) prohibits direct access to the native rules, and will be flipped on #
# in Bazel 1.0. #
################################################################################
load(":python_version.bzl", "define_python_version_flag")
load(":toolchain.bzl", "define_autodetecting_toolchain")
# Please do not use write_file.bzl outside of this package.
# See https://groups.google.com/d/msg/bazel-dev/I8IvJyoyo-s/AttqDcnOCgAJ
load(":write_file.bzl", "write_file")
package(default_visibility = ["//visibility:public"])
write_file(
name = "2to3",
out = select({
"//src/conditions:host_windows": "2to3.bat",
"//conditions:default": "2to3.sh",
}),
content = select({
"//src/conditions:host_windows": [
"@echo >&2 ERROR: 2to3 is not implemented.",
"@echo >&2 Please either build this target for PY2 or else set srcs_version to PY2ONLY instead of PY2.",
"@echo >&2 See https://github.com/bazelbuild/bazel/issues/1393#issuecomment-431110617",
"@exit /B 1",
],
"//conditions:default": [
"#!/bin/bash",
"echo >&2 'ERROR: 2to3 is not implemented.'",
"echo >&2 'Please either build this target for PY2 or else set srcs_version to PY2ONLY instead of PY2.'",
"echo >&2 'See https://github.com/bazelbuild/bazel/issues/1393#issuecomment-431110617'",
"exit 1",
],
}),
is_executable = True,
)
# These exports are needed for Starlark tooling to work on files that
# transitive load these ones. Ideally they would be bzl_library targets, but we
# don't have access to Skylib here. See
# https://github.com/bazelbuild/skydoc/issues/166.
exports_files([
"python_version.bzl",
"srcs_version.bzl",
"toolchain.bzl",
"utils.bzl",
"private/defs.bzl",
"private/py_test_alias.bzl",
# write_file.bzl fortunately doesn't need to be exposed because it's only
# used in this BUILD file.
])
filegroup(
name = "bzl_srcs",
srcs = glob(["*.bzl"]) + [
"private/defs.bzl",
"private/py_test_alias.bzl",
],
visibility = ["//tools:__pkg__"],
)
# This target can be used to inspect the current Python major version. To use,
# put it in the `flag_values` attribute of a `config_setting` and test it
# against the values "PY2" or "PY3". It will always match one or the other.
#
# If you do not need to test any other flags in combination with the Python
# version, then as a convenience you may use the predefined `config_setting`s
# `@bazel_tools//tools/python:PY2` and `@bazel_tools//tools/python:PY3`.
#
# Example usage:
#
# config_setting(
# name = "py3_on_arm",
# values = {"cpu": "arm"},
# flag_values = {"@bazel_tools//tools/python:python_version": "PY3"},
# )
#
# my_target(
# ...
# some_attr = select({
# ":py3_on_arm": ...,
# ...
# }),
# ...
# )
#
# Note that it is not allowed to `select()` on the built-in command-line flag
# `--python_version`. This is because historically, the flag's value has not
# always corresponded to the effective Python version, due to some indirections
# around legacy APIs, legacy semantics, and changing the default version from
# PY2 to PY3.
define_python_version_flag(
name = "python_version",
)
config_setting(
name = "PY2",
flag_values = {":python_version": "PY2"},
visibility = ["//visibility:public"],
)
config_setting(
name = "PY3",
flag_values = {":python_version": "PY3"},
visibility = ["//visibility:public"],
)
# The toolchain type for Python rules. Provides a Python 2 and/or Python 3
# runtime.
toolchain_type(name = "toolchain_type")
# A constraint_setting to use for constraints related to the location of the
# system Python 2 interpreter on a platform.
constraint_setting(name = "py2_interpreter_path")
# A constraint_setting to use for constraints related to the location of the
# system Python 3 interpreter on a platform.
constraint_setting(name = "py3_interpreter_path")
# Definitions for a Python toolchain that, at execution time, attempts to detect
# a platform runtime having the appropriate major Python version.
#
# This is a toolchain of last resort that gets automatically registered in all
# workspaces. Ideally you should register your own Python toolchain, which will
# supersede this one so long as its constraints match the target platform.
define_autodetecting_toolchain(
name = "autodetecting_toolchain",
pywrapper_template = "pywrapper_template.txt",
windows_config_setting = "@bazel_tools//src/conditions:windows",
)