move extra transition label generation into rules_python_internal

Author: rickeylev

MODULE.bazel

@@ -13,9 +13,9 @@ bazel_dep(name = "platforms", version = "0.0.11")
 # Use py_proto_library directly from protobuf repository
 bazel_dep(name = "protobuf", version = "29.0-rc2", repo_name = "com_google_protobuf")
 
-internal_deps = use_extension("//python/private:internal_deps.bzl", "internal_deps")
+rules_python_config = use_extension("//python/extensions:config.bzl", "config")
 use_repo(
-    internal_deps,
+    rules_python_config,
     "pypi__build",
     "pypi__click",
     "pypi__colorama",
@@ -34,12 +34,6 @@ use_repo(
     "rules_python_internal",
 )
 
-rules_python_config = use_extension(
-    "//python/extensions:config.bzl",
-    "rules_python_config",
-)
-use_repo(rules_python_config, "rules_python_config")
-
 # We need to do another use_extension call to expose the "pythons_hub"
 # repo.
 python = use_extension("//python/extensions:python.bzl", "python")
@@ -226,7 +220,7 @@ use_repo(
 
 dev_rules_python_config = use_extension(
     "//python/extensions:config.bzl",
-    "rules_python_config",
+    "config",
     dev_dependency = True,
 )
 dev_rules_python_config.add_transition_setting(

python/extensions/BUILD.bazel

@@ -45,6 +45,6 @@ bzl_library(
     srcs = ["config.bzl"],
     visibility = ["//:__subpackages__"],
     deps = [
-        "//python/private:rules_python_config_repo_bzl",
+        "//python/private:internal_config_repo_bzl",
     ],
 )

python/extensions/config.bzl

@@ -1,21 +1,8 @@
 """Extension for configuring global settings of rules_python."""
 
-load("//python/private:rules_python_config_repo.bzl", "rules_python_config_repo")
-
-def _rules_python_config_impl(mctx):
-    transition_setting_generators = {}
-    for mod in mctx.modules:
-        for tag in mod.tags.add_transition_setting:
-            setting = str(tag.setting)
-            if setting not in transition_setting_generators:
-                transition_setting_generators[setting] = []
-            transition_setting_generators[setting].append(mod.name)
-
-    rules_python_config_repo(
-        name = "rules_python_config",
-        transition_setting_generators = transition_setting_generators,
-        transition_settings = transition_setting_generators.keys(),
-    )
+load("@bazel_skylib//lib:modules.bzl", "modules")
+load("//python/private:internal_config_repo.bzl", "internal_config_repo")
+load("//python/private/pypi:deps.bzl", "pypi_deps")
 
 _add_transition_setting = tag_class(
     doc = """
@@ -35,13 +22,32 @@ to repositories that are expensive to create or invalidate frequently.
     },
 )
 
-rules_python_config = module_extension(
+def _config_impl(mctx):
+    transition_setting_generators = {}
+    transition_settings = []
+    for mod in mctx.modules:
+        for tag in mod.tags.add_transition_setting:
+            setting = str(tag.setting)
+            if setting not in transition_setting_generators:
+                transition_setting_generators[setting] = []
+                transition_settings.append(setting)
+            transition_setting_generators[setting].append(mod.name)
+
+    internal_config_repo(
+        name = "rules_python_internal",
+        transition_setting_generators = transition_setting_generators,
+        transition_settings = transition_settings,
+    )
+
+    pypi_deps()
+
+config = module_extension(
     doc = """Global settings for rules_python.
 
 :::{versionadded} VERSION_NEXT_FEATURE
 :::
 """,
-    implementation = _rules_python_config_impl,
+    implementation = _config_impl,
     tag_classes = {
         "add_transition_setting": _add_transition_setting,
     },

python/private/BUILD.bazel

@@ -506,7 +506,6 @@ bzl_library(
         ":bazel_tools_bzl",
         ":internal_config_repo_bzl",
         ":pythons_hub_bzl",
-        ":rules_python_config_repo_bzl",
         "//python:versions_bzl",
         "//python/private/pypi:deps_bzl",
     ],
@@ -627,14 +626,6 @@ bzl_library(
     ],
 )
 
-bzl_library(
-    name = "rules_python_config_repo_bzl",
-    srcs = ["rules_python_config_repo.bzl"],
-    deps = [
-        ":repo_utils_bzl",
-    ],
-)
-
 bzl_library(
     name = "sentinel_bzl",
     srcs = ["sentinel.bzl"],
@@ -672,7 +663,7 @@ bzl_library(
     deps = [
         "common_labels_bzl",
         "@bazel_skylib//lib:collections",
-        "@rules_python_config//:extra_transition_settings_bzl",
+        "@rules_python_internal//:extra_transition_settings_bzl",
     ],
 )
 

python/private/internal_config_repo.bzl

@@ -19,6 +19,7 @@ settings for rules to later use.
 """
 
 load(":repo_utils.bzl", "repo_utils")
+load("//python/private:text_util.bzl", "render")
 
 _ENABLE_PIPSTAR_ENVVAR_NAME = "RULES_PYTHON_ENABLE_PIPSTAR"
 _ENABLE_PIPSTAR_DEFAULT = "0"
@@ -27,7 +28,7 @@ _ENABLE_PYSTAR_DEFAULT = "1"
 _ENABLE_DEPRECATION_WARNINGS_ENVVAR_NAME = "RULES_PYTHON_DEPRECATION_WARNINGS"
 _ENABLE_DEPRECATION_WARNINGS_DEFAULT = "0"
 
-_CONFIG_TEMPLATE = """\
+_CONFIG_TEMPLATE = """
 config = struct(
   enable_pystar = {enable_pystar},
   enable_pipstar = {enable_pipstar},
@@ -40,12 +41,12 @@ config = struct(
 
 # The py_internal symbol is only accessible from within @rules_python, so we have to
 # load it from there and re-export it so that rules_python can later load it.
-_PY_INTERNAL_SHIM = """\
+_PY_INTERNAL_SHIM = """
 load("@rules_python//tools/build_defs/python/private:py_internal_renamed.bzl", "py_internal_renamed")
 py_internal_impl = py_internal_renamed
 """
 
-ROOT_BUILD_TEMPLATE = """\
+ROOT_BUILD_TEMPLATE = """
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 
 package(
@@ -64,6 +65,26 @@ bzl_library(
     srcs = ["py_internal.bzl"],
     deps = [{py_internal_dep}],
 )
+
+bzl_library(
+    name = "extra_transition_settings_bzl",
+    srcs = ["extra_transition_settings.bzl"],
+)
+"""
+
+_EXTRA_TRANSITIONS_TEMPLATE = """
+# Generated by @rules_python//python/private:internal_config_repo.bzl
+#
+# For a list of what modules added what labels, see
+# transition_settings_debug.txt
+
+EXTRA_TRANSITION_SETTINGS = {labels}
+"""
+
+_TRANSITION_SETTINGS_DEBUG_TEMPLATE = """
+# Generated by @rules_python//python/private:internal_config_repo.bzl
+
+{lines}
 """
 
 def _internal_config_repo_impl(rctx):
@@ -113,13 +134,33 @@ def _internal_config_repo_impl(rctx):
         visibility = visibility,
     ))
     rctx.file("py_internal.bzl", shim_content)
+
+    rctx.file(
+        "extra_transition_settings.bzl",
+        _EXTRA_TRANSITIONS_TEMPLATE.format(
+            labels = render.list(rctx.attr.transition_settings),
+        ),
+    )
+    debug_lines = [
+        "{} added by modules: {}".format(setting, ", ".join(sorted(requesters)))
+        for setting, requesters in rctx.attr.transition_setting_generators.items()
+    ]
+    rctx.file(
+        "transition_settings_debug.txt",
+        _TRANSITION_SETTINGS_DEBUG_TEMPLATE.format(lines = "\n".join(debug_lines)),
+    )
+
     return None
 
 internal_config_repo = repository_rule(
     implementation = _internal_config_repo_impl,
     configure = True,
     environ = [_ENABLE_PYSTAR_ENVVAR_NAME],
+    attrs = {
+        "transition_setting_generators": attr.string_list_dict(),
+        "transition_settings": attr.string_list(),
+    },
 )
 
 def _bool_from_environ(rctx, key, default):
-    return bool(int(repo_utils.getenv(rctx, key, default)))
+    return bool(int(repo_utils.getenv(rctx, key, default)))

python/private/internal_deps.bzl

@@ -20,7 +20,6 @@ load("//python:versions.bzl", "MINOR_MAPPING", "TOOL_VERSIONS")
 load("//python/private/pypi:deps.bzl", "pypi_deps")
 load(":internal_config_repo.bzl", "internal_config_repo")
 load(":pythons_hub.bzl", "hub_repo")
-load(":rules_python_config_repo.bzl", "rules_python_config_repo")
 
 def http_archive(**kwargs):
     maybe(_http_archive, **kwargs)
@@ -35,15 +34,14 @@ def py_repositories(transition_settings = []):
         transition_settings: A list of labels that terminal rules transition on
             by default.
     """
+
+    # NOTE: The @rules_python_internal repo is special cased by Bazel: it
+    # has autoloading disabled. This allows the rules to load from it
+    # without triggering recursion.
     maybe(
         internal_config_repo,
         name = "rules_python_internal",
     )
-    maybe(
-        rules_python_config_repo,
-        name = "rules_python_config",
-        transition_settings = transition_settings,
-    )
     maybe(
         hub_repo,
         name = "pythons_hub",

python/private/py_repositories.bzl

@@ -4,7 +4,7 @@ Terminal rules are e.g. py_binary, py_test, or packaging rules.
 """
 
 load("@bazel_skylib//lib:collections.bzl", "collections")
-load("@rules_python_config//:extra_transition_settings.bzl", "EXTRA_TRANSITION_SETTINGS")
+load("@rules_python_internal//:extra_transition_settings.bzl", "EXTRA_TRANSITION_SETTINGS")
 load(":common_labels.bzl", "labels")
 
 _BASE_TRANSITION_LABELS = [