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"Repo rule used by bzlmod extension to create a repo that has a map of Python interpreters and their labels" 16 17load("//python:versions.bzl", "PLATFORMS") 18load(":text_util.bzl", "render") 19load(":toolchains_repo.bzl", "python_toolchain_build_file_content") 20 21def _have_same_length(*lists): 22 if not lists: 23 fail("expected at least one list") 24 return len({len(length): None for length in lists}) == 1 25 26_HUB_BUILD_FILE_TEMPLATE = """\ 27load("@bazel_skylib//:bzl_library.bzl", "bzl_library") 28load("@@{rules_python}//python/private:py_toolchain_suite.bzl", "py_toolchain_suite") 29 30bzl_library( 31 name = "interpreters_bzl", 32 srcs = ["interpreters.bzl"], 33 visibility = ["@rules_python//:__subpackages__"], 34) 35 36bzl_library( 37 name = "versions_bzl", 38 srcs = ["versions.bzl"], 39 visibility = ["@rules_python//:__subpackages__"], 40) 41 42{toolchains} 43""" 44 45def _hub_build_file_content( 46 prefixes, 47 python_versions, 48 set_python_version_constraints, 49 user_repository_names, 50 workspace_location, 51 loaded_platforms): 52 """This macro iterates over each of the lists and returns the toolchain content. 53 54 python_toolchain_build_file_content is called to generate each of the toolchain 55 definitions. 56 """ 57 58 if not _have_same_length(python_versions, set_python_version_constraints, user_repository_names): 59 fail("all lists must have the same length") 60 61 # Iterate over the length of python_versions and call 62 # build the toolchain content by calling python_toolchain_build_file_content 63 toolchains = "\n".join( 64 [ 65 python_toolchain_build_file_content( 66 prefix = prefixes[i], 67 python_version = python_versions[i], 68 set_python_version_constraint = set_python_version_constraints[i], 69 user_repository_name = user_repository_names[i], 70 loaded_platforms = { 71 k: v 72 for k, v in PLATFORMS.items() 73 if k in loaded_platforms[python_versions[i]] 74 }, 75 ) 76 for i in range(len(python_versions)) 77 ], 78 ) 79 80 return _HUB_BUILD_FILE_TEMPLATE.format( 81 toolchains = toolchains, 82 rules_python = workspace_location.workspace_name, 83 ) 84 85_interpreters_bzl_template = """ 86INTERPRETER_LABELS = {{ 87{interpreter_labels} 88}} 89""" 90 91_line_for_hub_template = """\ 92 "{name}_host": Label("@{name}_host//:python"), 93""" 94 95_versions_bzl_template = """ 96DEFAULT_PYTHON_VERSION = "{default_python_version}" 97MINOR_MAPPING = {minor_mapping} 98PYTHON_VERSIONS = {python_versions} 99""" 100 101def _hub_repo_impl(rctx): 102 # Create the various toolchain definitions and 103 # write them to the BUILD file. 104 rctx.file( 105 "BUILD.bazel", 106 _hub_build_file_content( 107 rctx.attr.toolchain_prefixes, 108 rctx.attr.toolchain_python_versions, 109 rctx.attr.toolchain_set_python_version_constraints, 110 rctx.attr.toolchain_user_repository_names, 111 rctx.attr._rules_python_workspace, 112 rctx.attr.loaded_platforms, 113 ), 114 executable = False, 115 ) 116 117 # Create a dict that is later used to create 118 # a symlink to a interpreter. 119 interpreter_labels = "".join([ 120 _line_for_hub_template.format(name = name) 121 for name in rctx.attr.toolchain_user_repository_names 122 ]) 123 124 rctx.file( 125 "interpreters.bzl", 126 _interpreters_bzl_template.format( 127 interpreter_labels = interpreter_labels, 128 ), 129 executable = False, 130 ) 131 132 rctx.file( 133 "versions.bzl", 134 _versions_bzl_template.format( 135 default_python_version = rctx.attr.default_python_version, 136 minor_mapping = render.dict(rctx.attr.minor_mapping), 137 python_versions = rctx.attr.python_versions or render.list(sorted({ 138 v: None 139 for v in rctx.attr.toolchain_python_versions 140 })), 141 ), 142 executable = False, 143 ) 144 145hub_repo = repository_rule( 146 doc = """\ 147This private rule create a repo with a BUILD file that contains a map of interpreter names 148and the labels to said interpreters. This map is used to by the interpreter hub extension. 149This rule also writes out the various toolchains for the different Python versions. 150""", 151 implementation = _hub_repo_impl, 152 attrs = { 153 "default_python_version": attr.string( 154 doc = "Default Python version for the build in `X.Y` or `X.Y.Z` format.", 155 mandatory = True, 156 ), 157 "loaded_platforms": attr.string_list_dict( 158 doc = "The list of loaded platforms keyed by the toolchain full python version", 159 ), 160 "minor_mapping": attr.string_dict( 161 doc = "The minor mapping of the `X.Y` to `X.Y.Z` format that is used in config settings.", 162 mandatory = True, 163 ), 164 "python_versions": attr.string_list( 165 doc = "The list of python versions to include in the `interpreters.bzl` if the toolchains are not specified. Used in `WORKSPACE` builds.", 166 mandatory = False, 167 ), 168 "toolchain_prefixes": attr.string_list( 169 doc = "List prefixed for the toolchains", 170 mandatory = True, 171 ), 172 "toolchain_python_versions": attr.string_list( 173 doc = "List of Python versions for the toolchains. In `X.Y.Z` format.", 174 mandatory = True, 175 ), 176 "toolchain_set_python_version_constraints": attr.string_list( 177 doc = "List of version contraints for the toolchains", 178 mandatory = True, 179 ), 180 "toolchain_user_repository_names": attr.string_list( 181 doc = "List of the user repo names for the toolchains", 182 mandatory = True, 183 ), 184 "_rules_python_workspace": attr.label(default = Label("//:does_not_matter_what_this_name_is")), 185 }, 186) 187