1# Copyright 2023 The Bazel Authors. All rights reserved. 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14 15"""Public entry point for current_py_toolchain rule.""" 16 17def _current_py_toolchain_impl(ctx): 18 toolchain = ctx.toolchains[ctx.attr._toolchain] 19 20 direct = [] 21 transitive = [] 22 vars = {} 23 24 if toolchain.py3_runtime and toolchain.py3_runtime.interpreter: 25 direct.append(toolchain.py3_runtime.interpreter) 26 transitive.append(toolchain.py3_runtime.files) 27 vars["PYTHON3"] = toolchain.py3_runtime.interpreter.path 28 29 if toolchain.py2_runtime and toolchain.py2_runtime.interpreter: 30 direct.append(toolchain.py2_runtime.interpreter) 31 transitive.append(toolchain.py2_runtime.files) 32 vars["PYTHON2"] = toolchain.py2_runtime.interpreter.path 33 34 files = depset(direct, transitive = transitive) 35 return [ 36 toolchain, 37 platform_common.TemplateVariableInfo(vars), 38 DefaultInfo( 39 runfiles = ctx.runfiles(transitive_files = files), 40 files = files, 41 ), 42 ] 43 44current_py_toolchain = rule( 45 doc = """ 46 This rule exists so that the current python toolchain can be used in the `toolchains` attribute of 47 other rules, such as genrule. It allows exposing a python toolchain after toolchain resolution has 48 happened, to a rule which expects a concrete implementation of a toolchain, rather than a 49 toolchain_type which could be resolved to that toolchain. 50 """, 51 implementation = _current_py_toolchain_impl, 52 attrs = { 53 "_toolchain": attr.string(default = str(Label("@bazel_tools//tools/python:toolchain_type"))), 54 }, 55 toolchains = [ 56 str(Label("@bazel_tools//tools/python:toolchain_type")), 57 ], 58) 59