Revert "fix(toolchain): do not force users to depend on optional toolchains"

This reverts commit 7db60b1.

Author: aignas

CHANGELOG.md

@@ -28,13 +28,7 @@ A brief description of the categories of changes:
 * `protobuf`/`com_google_protobuf` dependency bumped to `v24.4`
 
 ### Fixed
-* The targets would depend on the `exec_tools_toolchain_type` toolchain if it
-  was registered even though the pre-compilation was not enabled. This has been
-  fixed to not be the case anymore. Fixes
-  [#1967](https://github.com/bazelbuild/rules_python/issues/1967). Users
-  wanting to use the `precompile` feature may have to set the config setting to
-  always do the precompilation and per-target pre-compilation is for now
-  disabled.
+* Nothing yet
 
 ### Removed
 * Nothing yet

python/config_settings/BUILD.bazel

@@ -1,4 +1,3 @@
-load("@bazel_skylib//lib:selects.bzl", "selects")
 load("@bazel_skylib//rules:common_settings.bzl", "string_flag")
 load(
     "//python/private:flags.bzl",
@@ -129,45 +128,3 @@ string_flag(
     )
     for flag in INTERNAL_FLAGS
 ]
-
-config_setting(
-    name = "_precompile_enabled",
-    flag_values = {
-        ":precompile": PrecompileFlag.ENABLED,
-    },
-    # Only public because it is used in toolchain definition
-    visibility = ["//visibility:public"],
-)
-
-config_setting(
-    name = "_precompile_enabled_generated_source",
-    flag_values = {
-        ":precompile": PrecompileFlag.IF_GENERATED_SOURCE,
-    },
-    # Only public because it is used in toolchain definition
-    visibility = ["//visibility:public"],
-)
-
-config_setting(
-    name = "_precompile_enabled_force",
-    flag_values = {
-        ":precompile": PrecompileFlag.FORCE_ENABLED,
-    },
-    # Only public because it is used in toolchain definition
-    visibility = ["//visibility:public"],
-)
-
-# FIXME @aignas 2024-06-14: this currently does not handle the `auto` value of
-# the flag correctly. Right now the behaviour is to disable the pre-compilation
-# via the _precompile_flag_get_effective_value function default to disabled if
-# it the flag is "AUTO", however we may need to revisit this.
-selects.config_setting_group(
-    name = "is_precompile_enabled",
-    match_any = [
-        ":_precompile_enabled",
-        ":_precompile_enabled_force",
-        ":_precompile_enabled_generated_source",
-    ],
-    # Only public because it is used in toolchain definition
-    visibility = ["//visibility:public"],
-)

python/private/BUILD.bazel

@@ -59,7 +59,6 @@ bzl_library(
     name = "autodetecting_toolchain_bzl",
     srcs = ["autodetecting_toolchain.bzl"],
     deps = [
-        ":toolchain_types_bzl",
         "//python:py_runtime_bzl",
         "//python:py_runtime_pair_bzl",
     ],

python/private/autodetecting_toolchain.bzl

@@ -16,7 +16,6 @@
 
 load("//python:py_runtime.bzl", "py_runtime")
 load("//python:py_runtime_pair.bzl", "py_runtime_pair")
-load("//python/private:toolchain_types.bzl", "TARGET_TOOLCHAIN_TYPE")
 
 def define_autodetecting_toolchain(name):
     """Defines the autodetecting Python toolchain.
@@ -66,6 +65,6 @@ def define_autodetecting_toolchain(name):
     native.toolchain(
         name = name,
         toolchain = ":_autodetecting_py_runtime_pair",
-        toolchain_type = TARGET_TOOLCHAIN_TYPE,
+        toolchain_type = ":toolchain_type",
         visibility = ["//visibility:public"],
     )

python/private/flags.bzl

@@ -34,7 +34,7 @@ BootstrapImplFlag = enum(
 def _precompile_flag_get_effective_value(ctx):
     value = ctx.attr._precompile_flag[BuildSettingInfo].value
     if value == PrecompileFlag.AUTO:
-        value = PrecompileFlag.IF_GENERATED_SOURCE
+        value = PrecompileFlag.DISABLED
     return value
 
 # Determines if Python source files should be compiled at build time.

python/private/py_toolchain_suite.bzl

@@ -107,10 +107,7 @@ def py_toolchain_suite(*, prefix, user_repository_name, python_version, set_pyth
         ),
         toolchain_type = EXEC_TOOLS_TOOLCHAIN_TYPE,
         # The target settings capture the Python version
-        target_settings = select({
-            Label("//python/config_settings:is_precompile_enabled"): target_settings,
-            "//conditions:default": [Label("//python/config_settings:is_precompile_enabled")],
-        }),
+        target_settings = target_settings,
         exec_compatible_with = kwargs.get("target_compatible_with"),
     )
 

tests/base_rules/precompile/precompile_tests.bzl

@@ -61,7 +61,6 @@ def _test_precompile_enabled_setup(name, py_rule, **kwargs):
         target = name + "_subject",
         config_settings = {
             "//command_line_option:extra_toolchains": _TEST_TOOLCHAINS,
-            PRECOMPILE: "enabled",
         },
     )
 
@@ -120,7 +119,6 @@ def _test_pyc_only(name):
         config_settings = {
             "//command_line_option:extra_toolchains": _TEST_TOOLCHAINS,
             ##PRECOMPILE_SOURCE_RETENTION: "omit_source",
-            PRECOMPILE: "enabled",
         },
         target = name + "_subject",
     )
@@ -163,7 +161,6 @@ def _test_precompile_if_generated(name):
         target = name + "_subject",
         config_settings = {
             "//command_line_option:extra_toolchains": _TEST_TOOLCHAINS,
-            PRECOMPILE: "enabled",
         },
     )
 
@@ -206,7 +203,6 @@ def _test_omit_source_if_generated_source(name):
         config_settings = {
             "//command_line_option:extra_toolchains": _TEST_TOOLCHAINS,
             PRECOMPILE_SOURCE_RETENTION: "omit_if_generated_source",
-            PRECOMPILE: "enabled",
         },
     )
 
@@ -292,7 +288,6 @@ def _test_precompiler_action(name):
         target = name + "_subject",
         config_settings = {
             "//command_line_option:extra_toolchains": _TEST_TOOLCHAINS,
-            PRECOMPILE: "enabled",
         },
     )