# Copyright 2023 The Bazel Authors. All rights reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"Module extension that finds the current toolchain Python binary and creates a symlink to it."

load("@pythons_hub//:interpreters.bzl", "INTERPRETER_LABELS")

def _interpreter_impl(mctx):

for mod in mctx.modules:

for install_attr in mod.tags.install:

_interpreter_repo(

name = install_attr.name,

python_name = install_attr.python_name,

)

interpreter = module_extension(

doc = """\

This extension is used to expose the underlying platform-specific

interpreter registered as a toolchain. It is used by users to get

a label to the interpreter for use with pip.parse

in the MODULES.bazel file.

""",

implementation = _interpreter_impl,

tag_classes = {

"install": tag_class(

attrs = {

"name": attr.string(

doc = "Name of the interpreter, we use this name to set the interpreter for pip.parse",

mandatory = True,

),

"python_name": attr.string(

doc = "The name set in the previous python.toolchain call.",

mandatory = True,

),

},

),

},

)

def _interpreter_repo_impl(rctx):

rctx.file("BUILD.bazel", "")

actual_interpreter_label = INTERPRETER_LABELS.get(rctx.attr.python_name)

if actual_interpreter_label == None:

fail("Unable to find interpreter with name '{}'".format(rctx.attr.python_name))

rctx.symlink(actual_interpreter_label, "python")

_interpreter_repo = repository_rule(

doc = """\

Load the INTERPRETER_LABELS map. This map contain of all of the Python binaries

by name and a label the points to the interpreter binary. The

binaries are downloaded as part of the python toolchain setup.

The rule finds the label and creates a symlink named "python" to that

label. This symlink is then used by pip.

""",

implementation = _interpreter_repo_impl,

attrs = {

"python_name": attr.string(

mandatory = True,

doc = "Name of the Python toolchain",

),

},

)