|
14 | 14 |
|
15 | 15 | "Python toolchain module extensions for use with bzlmod" |
16 | 16 |
|
17 | | -load("//python:repositories.bzl", "python_register_toolchains") |
18 | | -load("//python/extensions/private:pythons_hub.bzl", "hub_repo") |
19 | | -load("//python/private:toolchains_repo.bzl", "multi_toolchain_aliases") |
| 17 | +load("//python/private/bzlmod:python.bzl", _python = "python") |
20 | 18 |
|
21 | | -# This limit can be increased essentially arbitrarily, but doing so will cause a rebuild of all |
22 | | -# targets using any of these toolchains due to the changed repository name. |
23 | | -_MAX_NUM_TOOLCHAINS = 9999 |
24 | | -_TOOLCHAIN_INDEX_PAD_LENGTH = len(str(_MAX_NUM_TOOLCHAINS)) |
25 | | - |
26 | | -def _toolchain_prefix(index, name): |
27 | | - """Prefixes the given name with the index, padded with zeros to ensure lexicographic sorting. |
28 | | -
|
29 | | - Examples: |
30 | | - _toolchain_prefix( 2, "foo") == "_0002_foo_" |
31 | | - _toolchain_prefix(2000, "foo") == "_2000_foo_" |
32 | | - """ |
33 | | - return "_{}_{}_".format(_left_pad_zero(index, _TOOLCHAIN_INDEX_PAD_LENGTH), name) |
34 | | - |
35 | | -def _left_pad_zero(index, length): |
36 | | - if index < 0: |
37 | | - fail("index must be non-negative") |
38 | | - return ("0" * length + str(index))[-length:] |
39 | | - |
40 | | -# Printing a warning msg not debugging, so we have to disable |
41 | | -# the buildifier check. |
42 | | -# buildifier: disable=print |
43 | | -def _print_warn(msg): |
44 | | - print("WARNING:", msg) |
45 | | - |
46 | | -def _python_register_toolchains(name, toolchain_attr, version_constraint): |
47 | | - """Calls python_register_toolchains and returns a struct used to collect the toolchains. |
48 | | - """ |
49 | | - python_register_toolchains( |
50 | | - name = name, |
51 | | - python_version = toolchain_attr.python_version, |
52 | | - register_coverage_tool = toolchain_attr.configure_coverage_tool, |
53 | | - ignore_root_user_error = toolchain_attr.ignore_root_user_error, |
54 | | - set_python_version_constraint = version_constraint, |
55 | | - ) |
56 | | - return struct( |
57 | | - python_version = toolchain_attr.python_version, |
58 | | - set_python_version_constraint = str(version_constraint), |
59 | | - name = name, |
60 | | - ) |
61 | | - |
62 | | -def _python_impl(module_ctx): |
63 | | - # The toolchain info structs to register, in the order to register them in. |
64 | | - toolchains = [] |
65 | | - |
66 | | - # We store the default toolchain separately to ensure it is the last |
67 | | - # toolchain added to toolchains. |
68 | | - default_toolchain = None |
69 | | - |
70 | | - # Map of string Major.Minor to the toolchain name and module name |
71 | | - global_toolchain_versions = {} |
72 | | - |
73 | | - for mod in module_ctx.modules: |
74 | | - module_toolchain_versions = [] |
75 | | - |
76 | | - for toolchain_attr in mod.tags.toolchain: |
77 | | - toolchain_version = toolchain_attr.python_version |
78 | | - toolchain_name = "python_" + toolchain_version.replace(".", "_") |
79 | | - |
80 | | - # Duplicate versions within a module indicate a misconfigured module. |
81 | | - if toolchain_version in module_toolchain_versions: |
82 | | - _fail_duplicate_module_toolchain_version(toolchain_version, mod.name) |
83 | | - module_toolchain_versions.append(toolchain_version) |
84 | | - |
85 | | - # Ignore version collisions in the global scope because there isn't |
86 | | - # much else that can be done. Modules don't know and can't control |
87 | | - # what other modules do, so the first in the dependency graph wins. |
88 | | - if toolchain_version in global_toolchain_versions: |
89 | | - # If the python version is explicitly provided by the root |
90 | | - # module, they should not be warned for choosing the same |
91 | | - # version that rules_python provides as default. |
92 | | - first = global_toolchain_versions[toolchain_version] |
93 | | - if mod.name != "rules_python" or not first.is_root: |
94 | | - _warn_duplicate_global_toolchain_version( |
95 | | - toolchain_version, |
96 | | - first = first, |
97 | | - second_toolchain_name = toolchain_name, |
98 | | - second_module_name = mod.name, |
99 | | - ) |
100 | | - continue |
101 | | - global_toolchain_versions[toolchain_version] = struct( |
102 | | - toolchain_name = toolchain_name, |
103 | | - module_name = mod.name, |
104 | | - is_root = mod.is_root, |
105 | | - ) |
106 | | - |
107 | | - # Only the root module and rules_python are allowed to specify the default |
108 | | - # toolchain for a couple reasons: |
109 | | - # * It prevents submodules from specifying different defaults and only |
110 | | - # one of them winning. |
111 | | - # * rules_python needs to set a soft default in case the root module doesn't, |
112 | | - # e.g. if the root module doesn't use Python itself. |
113 | | - # * The root module is allowed to override the rules_python default. |
114 | | - if mod.is_root: |
115 | | - # A single toolchain is treated as the default because it's unambiguous. |
116 | | - is_default = toolchain_attr.is_default or len(mod.tags.toolchain) == 1 |
117 | | - elif mod.name == "rules_python" and not default_toolchain: |
118 | | - # We don't do the len() check because we want the default that rules_python |
119 | | - # sets to be clearly visible. |
120 | | - is_default = toolchain_attr.is_default |
121 | | - else: |
122 | | - is_default = False |
123 | | - |
124 | | - # We have already found one default toolchain, and we can only have |
125 | | - # one. |
126 | | - if is_default and default_toolchain != None: |
127 | | - _fail_multiple_default_toolchains( |
128 | | - first = default_toolchain.name, |
129 | | - second = toolchain_name, |
130 | | - ) |
131 | | - |
132 | | - toolchain_info = _python_register_toolchains( |
133 | | - toolchain_name, |
134 | | - toolchain_attr, |
135 | | - version_constraint = not is_default, |
136 | | - ) |
137 | | - |
138 | | - if is_default: |
139 | | - default_toolchain = toolchain_info |
140 | | - else: |
141 | | - toolchains.append(toolchain_info) |
142 | | - |
143 | | - # A default toolchain is required so that the non-version-specific rules |
144 | | - # are able to match a toolchain. |
145 | | - if default_toolchain == None: |
146 | | - fail("No default Python toolchain configured. Is rules_python missing `is_default=True`?") |
147 | | - |
148 | | - # The last toolchain in the BUILD file is set as the default |
149 | | - # toolchain. We need the default last. |
150 | | - toolchains.append(default_toolchain) |
151 | | - |
152 | | - if len(toolchains) > _MAX_NUM_TOOLCHAINS: |
153 | | - fail("more than {} python versions are not supported".format(_MAX_NUM_TOOLCHAINS)) |
154 | | - |
155 | | - # Create the pythons_hub repo for the interpreter meta data and the |
156 | | - # the various toolchains. |
157 | | - hub_repo( |
158 | | - name = "pythons_hub", |
159 | | - default_python_version = default_toolchain.python_version, |
160 | | - toolchain_prefixes = [ |
161 | | - _toolchain_prefix(index, toolchain.name) |
162 | | - for index, toolchain in enumerate(toolchains) |
163 | | - ], |
164 | | - toolchain_python_versions = [t.python_version for t in toolchains], |
165 | | - toolchain_set_python_version_constraints = [t.set_python_version_constraint for t in toolchains], |
166 | | - toolchain_user_repository_names = [t.name for t in toolchains], |
167 | | - ) |
168 | | - |
169 | | - # This is require in order to support multiple version py_test |
170 | | - # and py_binary |
171 | | - multi_toolchain_aliases( |
172 | | - name = "python_versions", |
173 | | - python_versions = { |
174 | | - version: entry.toolchain_name |
175 | | - for version, entry in global_toolchain_versions.items() |
176 | | - }, |
177 | | - ) |
178 | | - |
179 | | -def _fail_duplicate_module_toolchain_version(version, module): |
180 | | - fail(("Duplicate module toolchain version: module '{module}' attempted " + |
181 | | - "to use version '{version}' multiple times in itself").format( |
182 | | - version = version, |
183 | | - module = module, |
184 | | - )) |
185 | | - |
186 | | -def _warn_duplicate_global_toolchain_version(version, first, second_toolchain_name, second_module_name): |
187 | | - _print_warn(( |
188 | | - "Ignoring toolchain '{second_toolchain}' from module '{second_module}': " + |
189 | | - "Toolchain '{first_toolchain}' from module '{first_module}' " + |
190 | | - "already registered Python version {version} and has precedence" |
191 | | - ).format( |
192 | | - first_toolchain = first.toolchain_name, |
193 | | - first_module = first.module_name, |
194 | | - second_module = second_module_name, |
195 | | - second_toolchain = second_toolchain_name, |
196 | | - version = version, |
197 | | - )) |
198 | | - |
199 | | -def _fail_multiple_default_toolchains(first, second): |
200 | | - fail(("Multiple default toolchains: only one toolchain " + |
201 | | - "can have is_default=True. First default " + |
202 | | - "was toolchain '{first}'. Second was '{second}'").format( |
203 | | - first = first, |
204 | | - second = second, |
205 | | - )) |
206 | | - |
207 | | -python = module_extension( |
208 | | - doc = """Bzlmod extension that is used to register Python toolchains. |
209 | | -""", |
210 | | - implementation = _python_impl, |
211 | | - tag_classes = { |
212 | | - "toolchain": tag_class( |
213 | | - doc = """Tag class used to register Python toolchains. |
214 | | -Use this tag class to register one or more Python toolchains. This class |
215 | | -is also potentially called by sub modules. The following covers different |
216 | | -business rules and use cases. |
217 | | -
|
218 | | -Toolchains in the Root Module |
219 | | -
|
220 | | -This class registers all toolchains in the root module. |
221 | | -
|
222 | | -Toolchains in Sub Modules |
223 | | -
|
224 | | -It will create a toolchain that is in a sub module, if the toolchain |
225 | | -of the same name does not exist in the root module. The extension stops name |
226 | | -clashing between toolchains in the root module and toolchains in sub modules. |
227 | | -You cannot configure more than one toolchain as the default toolchain. |
228 | | -
|
229 | | -Toolchain set as the default version |
230 | | -
|
231 | | -This extension will not create a toolchain that exists in a sub module, |
232 | | -if the sub module toolchain is marked as the default version. If you have |
233 | | -more than one toolchain in your root module, you need to set one of the |
234 | | -toolchains as the default version. If there is only one toolchain it |
235 | | -is set as the default toolchain. |
236 | | -
|
237 | | -Toolchain repository name |
238 | | -
|
239 | | -A toolchain's repository name uses the format `python_{major}_{minor}`, e.g. |
240 | | -`python_3_10`. The `major` and `minor` components are |
241 | | -`major` and `minor` are the Python version from the `python_version` attribute. |
242 | | -""", |
243 | | - attrs = { |
244 | | - "configure_coverage_tool": attr.bool( |
245 | | - mandatory = False, |
246 | | - doc = "Whether or not to configure the default coverage tool for the toolchains.", |
247 | | - ), |
248 | | - "ignore_root_user_error": attr.bool( |
249 | | - default = False, |
250 | | - doc = "Whether the check for root should be ignored or not. This causes cache misses with .pyc files.", |
251 | | - mandatory = False, |
252 | | - ), |
253 | | - "is_default": attr.bool( |
254 | | - mandatory = False, |
255 | | - doc = "Whether the toolchain is the default version", |
256 | | - ), |
257 | | - "python_version": attr.string( |
258 | | - mandatory = True, |
259 | | - doc = "The Python version, in `major.minor` format, e.g " + |
260 | | - "'3.12', to create a toolchain for. Patch level " + |
261 | | - "granularity (e.g. '3.12.1') is not supported.", |
262 | | - ), |
263 | | - }, |
264 | | - ), |
265 | | - }, |
266 | | -) |
| 19 | +python = _python |
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