feat: support arbitrary target_settings in our platforms 3/n

CHANGELOG.md

@@ -64,7 +64,7 @@ END_UNRELEASED_TEMPLATE
 ### Added
 * (pypi) To configure the environment for `requirements.txt` evaluation, use the newly added
   developer preview of the `pip.default` tag class. Only `rules_python` and root modules can use
-  this feature. You can also configure `constraint_values` using `pip.default`.
+  this feature. You can also configure custom `config_settings` using `pip.default`.
 
 {#v0-0-0-removed}
 ### Removed

python/private/pypi/BUILD.bazel

@@ -64,6 +64,7 @@ bzl_library(
     deps = [
         ":flags_bzl",
         "//python/private:flags_bzl",
+        "@bazel_skylib//lib:selects",
     ],
 )
 

python/private/pypi/config_settings.bzl

@@ -70,6 +70,7 @@ suffix.
 :::
 """
 
+load("@bazel_skylib//lib:selects.bzl", "selects")
 load("//python/private:flags.bzl", "LibcFlag")
 load(":flags.bzl", "INTERNAL_FLAGS", "UniversalWhlFlag")
 
@@ -112,7 +113,7 @@ def config_settings(
         muslc_versions = [],
         osx_versions = [],
         name = None,
-        platform_constraint_values = {},
+        platform_config_settings = {},
         **kwargs):
     """Generate all of the pip config settings.
 
@@ -126,7 +127,7 @@ def config_settings(
             configure config settings for.
         osx_versions (list[str]): The list of OSX OS versions to configure
             config settings for.
-        platform_constraint_values: {type}`dict[str, list[str]]` the constraint
+        platform_config_settings: {type}`dict[str, list[str]]` the constraint
             values to use instead of the default ones. Key are platform names
             (a human-friendly platform string). Values are lists of
             `constraint_value` label strings.
@@ -142,13 +143,24 @@ def config_settings(
         # TODO @aignas 2025-06-15: allowing universal2 and platform specific wheels in one
         # closure is making things maybe a little bit too complicated.
         "osx_universal2": ["@platforms//os:osx"],
-    } | platform_constraint_values
+    } | platform_config_settings
 
     for python_version in python_versions:
-        for platform_name, constraint_values in target_platforms.items():
+        for platform_name, config_settings in target_platforms.items():
             suffix = "_{}".format(platform_name) if platform_name else ""
             os, _, cpu = platform_name.partition("_")
 
+            # We parse the target settings and if there is a "platforms//os" or
+            # "platforms//cpu" value in here, we also add it into the constraint_values
+            #
+            # this is to ensure that we can still pass all of the unit tests for config
+            # setting specialization.
+            constraint_values = []
+            for setting in config_settings:
+                setting_label = Label(setting)
+                if setting_label.repo_name == "platforms" and setting_label.package in ["os", "cpu"]:
+                    constraint_values.append(setting)
+
             _dist_config_settings(
                 suffix = suffix,
                 plat_flag_values = _plat_flag_values(
@@ -158,6 +170,7 @@ def config_settings(
                     glibc_versions = glibc_versions,
                     muslc_versions = muslc_versions,
                 ),
+                config_settings = config_settings,
                 constraint_values = constraint_values,
                 python_version = python_version,
                 **kwargs
@@ -318,7 +331,7 @@ def _plat_flag_values(os, cpu, osx_versions, glibc_versions, muslc_versions):
 
     return ret
 
-def _dist_config_setting(*, name, compatible_with = None, native = native, **kwargs):
+def _dist_config_setting(*, name, compatible_with = None, selects = selects, native = native, config_settings = None, **kwargs):
     """A macro to create a target for matching Python binary and source distributions.
 
     Args:
@@ -327,6 +340,12 @@ def _dist_config_setting(*, name, compatible_with = None, native = native, **kwa
             compatible with the given dist config setting. For example, if only
             non-freethreaded python builds are allowed, add
             FLAGS._is_py_freethreaded_no here.
+        config_settings: {type}`list[str | Label]` the list of target settings that must
+            be matched before we try to evaluate the config_setting that we may create in
+            this function.
+        selects (struct): The struct containing config_setting_group function
+            to use for creating config setting groups. Can be overridden for unit tests
+            reasons.
         native (struct): The struct containing alias and config_setting rules
             to use for creating the objects. Can be overridden for unit tests
             reasons.
@@ -346,4 +365,14 @@ def _dist_config_setting(*, name, compatible_with = None, native = native, **kwa
         )
         name = dist_config_setting_name
 
-    native.config_setting(name = name, **kwargs)
+    # first define the config setting that has all of the constraint values
+    _name = "_" + name
+    native.config_setting(
+        name = _name,
+        **kwargs
+    )
+    selects.config_setting_group(
+        name = name,
+        match_all = config_settings + [_name],
+        visibility = kwargs.get("visibility"),
+    )

python/private/pypi/extension.bzl

@@ -372,7 +372,7 @@ def _whl_repo(*, src, whl_library_args, is_multiple_versions, download_only, net
         ),
     )
 
-def _configure(config, *, platform, os_name, arch_name, constraint_values, env = {}, override = False):
+def _configure(config, *, platform, os_name, arch_name, config_settings, env = {}, override = False):
     """Set the value in the config if the value is provided"""
     config.setdefault("platforms", {})
     if platform:
@@ -387,7 +387,7 @@ def _configure(config, *, platform, os_name, arch_name, constraint_values, env =
             name = platform.replace("-", "_").lower(),
             os_name = os_name,
             arch_name = arch_name,
-            constraint_values = constraint_values,
+            config_settings = config_settings,
             env = env,
         )
     else:
@@ -414,7 +414,7 @@ def _create_config(defaults):
             arch_name = cpu,
             os_name = "linux",
             platform = "linux_{}".format(cpu),
-            constraint_values = [
+            config_settings = [
                 "@platforms//os:linux",
                 "@platforms//cpu:{}".format(cpu),
             ],
@@ -431,7 +431,7 @@ def _create_config(defaults):
             # See https://endoflife.date/macos
             os_name = "osx",
             platform = "osx_{}".format(cpu),
-            constraint_values = [
+            config_settings = [
                 "@platforms//os:osx",
                 "@platforms//cpu:{}".format(cpu),
             ],
@@ -443,7 +443,7 @@ def _create_config(defaults):
         arch_name = "x86_64",
         os_name = "windows",
         platform = "windows_x86_64",
-        constraint_values = [
+        config_settings = [
             "@platforms//os:windows",
             "@platforms//cpu:x86_64",
         ],
@@ -513,7 +513,7 @@ You cannot use both the additive_build_content and additive_build_content_file a
             _configure(
                 defaults,
                 arch_name = tag.arch_name,
-                constraint_values = tag.constraint_values,
+                config_settings = tag.config_settings,
                 env = tag.env,
                 os_name = tag.os_name,
                 platform = tag.platform,
@@ -693,9 +693,9 @@ You cannot use both the additive_build_content and additive_build_content_file a
             }
             for hub_name, extra_whl_aliases in extra_aliases.items()
         },
-        platform_constraint_values = {
+        platform_config_settings = {
             hub_name: {
-                platform_name: sorted([str(Label(cv)) for cv in p.constraint_values])
+                platform_name: sorted([str(Label(cv)) for cv in p.config_settings])
                 for platform_name, p in config.platforms.items()
             }
             for hub_name in hub_whl_map
@@ -790,7 +790,7 @@ def _pip_impl(module_ctx):
                 for key, values in whl_map.items()
             },
             packages = mods.exposed_packages.get(hub_name, []),
-            platform_constraint_values = mods.platform_constraint_values.get(hub_name, {}),
+            platform_config_settings = mods.platform_config_settings.get(hub_name, {}),
             groups = mods.hub_group_map.get(hub_name),
         )
 
@@ -812,10 +812,11 @@ Either this or {attr}`env` `platform_machine` key should be specified.
 :::
 """,
     ),
-    "constraint_values": attr.label_list(
+    "config_settings": attr.label_list(
         mandatory = True,
         doc = """\
-The constraint_values to use in select statements.
+The list of labels to `config_setting` targets that need to be matched for the platform to be
+selected.
 """,
     ),
     "os_name": attr.string(
@@ -1145,6 +1146,9 @@ terms used in this extension.
 
 [environment_markers]: https://packaging.python.org/en/latest/specifications/dependency-specifiers/#environment-markers
 :::
+
+:::{versionadded} VERSION_NEXT_FEATURE
+:::
 """,
         ),
         "override": _override_tag,

python/private/pypi/hub_repository.bzl

@@ -34,7 +34,7 @@ def _impl(rctx):
         },
         extra_hub_aliases = rctx.attr.extra_hub_aliases,
         requirement_cycles = rctx.attr.groups,
-        platform_constraint_values = rctx.attr.platform_constraint_values,
+        platform_config_settings = rctx.attr.platform_config_settings,
     )
     for path, contents in aliases.items():
         rctx.file(path, contents)
@@ -84,7 +84,7 @@ hub_repository = repository_rule(
 The list of packages that will be exposed via all_*requirements macros. Defaults to whl_map keys.
 """,
         ),
-        "platform_constraint_values": attr.string_list_dict(
+        "platform_config_settings": attr.string_list_dict(
             doc = "The constraint values for each platform name. The values are string canonical string Label representations",
             mandatory = False,
         ),

python/private/pypi/render_pkg_aliases.bzl

@@ -155,14 +155,14 @@ def _major_minor_versions(python_versions):
     # Use a dict as a simple set
     return sorted({_major_minor(v): None for v in python_versions})
 
-def render_multiplatform_pkg_aliases(*, aliases, platform_constraint_values = {}, **kwargs):
+def render_multiplatform_pkg_aliases(*, aliases, platform_config_settings = {}, **kwargs):
     """Render the multi-platform pkg aliases.
 
     Args:
         aliases: dict[str, list(whl_config_setting)] A list of aliases that will be
           transformed from ones having `filename` to ones having `config_setting`.
-        platform_constraint_values: {type}`dict[str, list[str]]` contains all of the
-            target platforms and their appropriate `constraint_values`.
+        platform_config_settings: {type}`dict[str, list[str]]` contains all of the
+            target platforms and their appropriate `target_settings`.
         **kwargs: extra arguments passed to render_pkg_aliases.
 
     Returns:
@@ -189,20 +189,20 @@ def render_multiplatform_pkg_aliases(*, aliases, platform_constraint_values = {}
         muslc_versions = flag_versions.get("muslc_versions", []),
         osx_versions = flag_versions.get("osx_versions", []),
         python_versions = _major_minor_versions(flag_versions.get("python_versions", [])),
-        platform_constraint_values = platform_constraint_values,
+        platform_config_settings = platform_config_settings,
         visibility = ["//:__subpackages__"],
     )
     return contents
 
-def _render_config_settings(platform_constraint_values, **kwargs):
+def _render_config_settings(platform_config_settings, **kwargs):
     return """\
 load("@rules_python//python/private/pypi:config_settings.bzl", "config_settings")
 
 {}""".format(render.call(
         "config_settings",
         name = repr("config_settings"),
-        platform_constraint_values = render.dict(
-            platform_constraint_values,
+        platform_config_settings = render.dict(
+            platform_config_settings,
             value_repr = render.list,
         ),
         **_repr_dict(value_repr = render.list, **kwargs)

tests/pypi/config_settings/config_settings_tests.bzl

@@ -657,7 +657,7 @@ def config_settings_test_suite(name):  # buildifier: disable=function-docstring
         glibc_versions = [(2, 14), (2, 17)],
         muslc_versions = [(1, 1)],
         osx_versions = [(10, 9), (11, 0)],
-        platform_constraint_values = {
+        platform_config_settings = {
             "linux_aarch64": [
                 "@platforms//cpu:aarch64",
                 "@platforms//os:linux",

tests/pypi/extension/extension_tests.bzl

@@ -78,19 +78,17 @@ def _parse_modules(env, enable_pipstar = 0, **kwargs):
 
 def _default(
         arch_name = None,
-        constraint_values = None,
+        config_settings = None,
         os_name = None,
         platform = None,
-        target_settings = None,
         env = None,
         whl_limit = None,
         whl_platforms = None):
     return struct(
         arch_name = arch_name,
-        constraint_values = constraint_values,
         os_name = os_name,
         platform = platform,
-        target_settings = target_settings,
+        config_settings = config_settings,
         env = env or {},
         whl_platforms = whl_platforms,
         whl_limit = whl_limit,
@@ -1051,7 +1049,7 @@ def _test_pipstar_platforms(env):
                 default = [
                     _default(
                         platform = "{}_{}".format(os, cpu),
-                        constraint_values = [
+                        config_settings = [
                             "@platforms//os:{}".format(os),
                             "@platforms//cpu:{}".format(cpu),
                         ],

tests/pypi/pkg_aliases/pkg_aliases_test.bzl

@@ -392,6 +392,9 @@ _tests.append(_test_multiplatform_whl_aliases_filename_versioned)
 def _mock_alias(container):
     return lambda name, **kwargs: container.append(name)
 
+def _mock_config_setting_group(container):
+    return lambda name, **kwargs: container.append(name)
+
 def _mock_config_setting(container):
     def _inner(name, flag_values = None, constraint_values = None, **_):
         if flag_values or constraint_values:
@@ -417,9 +420,12 @@ def _test_config_settings_exist_legacy(env):
         python_versions = ["3.11"],
         native = struct(
             alias = _mock_alias(available_config_settings),
-            config_setting = _mock_config_setting(available_config_settings),
+            config_setting = _mock_config_setting([]),
         ),
-        platform_constraint_values = {
+        selects = struct(
+            config_setting_group = _mock_config_setting_group(available_config_settings),
+        ),
+        platform_config_settings = {
             "linux_aarch64": [
                 "@platforms//cpu:aarch64",
                 "@platforms//os:linux",
@@ -454,7 +460,7 @@ def _test_config_settings_exist(env):
                 "any": {},
                 "macosx_11_0_arm64": {
                     "osx_versions": [(11, 0)],
-                    "platform_constraint_values": {
+                    "platform_config_settings": {
                         "osx_aarch64": [
                             "@platforms//cpu:aarch64",
                             "@platforms//os:osx",
@@ -463,7 +469,7 @@ def _test_config_settings_exist(env):
                 },
                 "manylinux_2_17_x86_64": {
                     "glibc_versions": [(2, 17), (2, 18)],
-                    "platform_constraint_values": {
+                    "platform_config_settings": {
                         "linux_x86_64": [
                             "@platforms//cpu:x86_64",
                             "@platforms//os:linux",
@@ -472,7 +478,7 @@ def _test_config_settings_exist(env):
                 },
                 "manylinux_2_18_x86_64": {
                     "glibc_versions": [(2, 17), (2, 18)],
-                    "platform_constraint_values": {
+                    "platform_config_settings": {
                         "linux_x86_64": [
                             "@platforms//cpu:x86_64",
                             "@platforms//os:linux",
@@ -481,7 +487,7 @@ def _test_config_settings_exist(env):
                 },
                 "musllinux_1_1_aarch64": {
                     "muslc_versions": [(1, 2), (1, 1), (1, 0)],
-                    "platform_constraint_values": {
+                    "platform_config_settings": {
                         "linux_aarch64": [
                             "@platforms//cpu:aarch64",
                             "@platforms//os:linux",
@@ -500,7 +506,10 @@ def _test_config_settings_exist(env):
                     python_versions = ["3.11"],
                     native = struct(
                         alias = _mock_alias(available_config_settings),
-                        config_setting = _mock_config_setting(available_config_settings),
+                        config_setting = _mock_config_setting([]),
+                    ),
+                    selects = struct(
+                        config_setting_group = _mock_config_setting_group(available_config_settings),
                     ),
                     **kwargs
                 )