chore: remove semantics.bzl (#2725)

semantics.bzl is an artifact of how the rules avoided patching when they
were part of Bazel.
With the code moved out of Bazel, such helper files aren't necessary
anymore.

Work towards #2522

Author: rickeylev

python/private/BUILD.bazel

@@ -72,7 +72,6 @@ bzl_library(
         ":py_internal_bzl",
         ":reexports_bzl",
         ":rules_cc_srcs_bzl",
-        ":semantics_bzl",
         "@bazel_skylib//rules:common_settings",
     ],
 )
@@ -131,7 +130,6 @@ bzl_library(
         ":py_internal_bzl",
         ":reexports_bzl",
         ":rules_cc_srcs_bzl",
-        ":semantics_bzl",
         "@bazel_skylib//lib:paths",
     ],
 )
@@ -302,7 +300,6 @@ bzl_library(
         ":attributes_bzl",
         ":py_executable_bzl",
         ":rule_builders_bzl",
-        ":semantics_bzl",
         "@bazel_skylib//lib:dicts",
     ],
 )
@@ -537,7 +534,6 @@ bzl_library(
         ":common_bzl",
         ":py_executable_bzl",
         ":rule_builders_bzl",
-        ":semantics_bzl",
         "@bazel_skylib//lib:dicts",
     ],
 )
@@ -677,11 +673,6 @@ bzl_library(
     ],
 )
 
-bzl_library(
-    name = "semantics_bzl",
-    srcs = ["semantics.bzl"],
-)
-
 # Needed to define bzl_library targets for docgen. (We don't define the
 # bzl_library target here because it'd give our users a transitive dependency
 # on Skylib.)

python/private/attributes.bzl

@@ -23,11 +23,6 @@ load(":py_info.bzl", "PyInfo")
 load(":py_internal.bzl", "py_internal")
 load(":reexports.bzl", "BuiltinPyInfo")
 load(":rule_builders.bzl", "ruleb")
-load(
-    ":semantics.bzl",
-    "DEPS_ATTR_ALLOW_RULES",
-    "SRCS_ATTR_ALLOW_FILES",
-)
 
 _PackageSpecificationInfo = getattr(py_internal, "PackageSpecificationInfo", None)
 
@@ -250,9 +245,6 @@ PY_SRCS_ATTRS = dicts.add(
                 [PyInfo],
                 [CcInfo],
             ] + _MaybeBuiltinPyInfo,
-            # TODO(b/228692666): Google-specific; remove these allowances once
-            # the depot is cleaned up.
-            allow_rules = DEPS_ATTR_ALLOW_RULES,
             doc = """
 List of additional libraries to be linked in to the target.
 See comments about
@@ -359,8 +351,7 @@ as part of a runnable program (packaging rules may include them, however).
             allow_files = True,
         ),
         "srcs": lambda: attrb.LabelList(
-            # Google builds change the set of allowed files.
-            allow_files = SRCS_ATTR_ALLOW_FILES,
+            allow_files = [".py", ".py3"],
             # Necessary for --compile_one_dependency to work.
             flags = ["DIRECT_COMPILE_TIME_INPUT"],
             doc = """

python/private/py_executable.bzl

@@ -59,13 +59,6 @@ load(":py_internal.bzl", "py_internal")
 load(":py_runtime_info.bzl", "DEFAULT_STUB_SHEBANG", "PyRuntimeInfo")
 load(":reexports.bzl", "BuiltinPyInfo", "BuiltinPyRuntimeInfo")
 load(":rule_builders.bzl", "ruleb")
-load(
-    ":semantics.bzl",
-    "ALLOWED_MAIN_EXTENSIONS",
-    "BUILD_DATA_SYMLINK_PATH",
-    "IS_BAZEL",
-    "PY_RUNTIME_ATTR_NAME",
-)
 load(
     ":toolchain_types.bzl",
     "EXEC_TOOLS_TOOLCHAIN_TYPE",
@@ -1116,19 +1109,12 @@ def _get_runtime_details(ctx, semantics):
     #
     # TOOD(bazelbuild/bazel#7901): Remove this once --python_path flag is removed.
 
-    if IS_BAZEL:
-        flag_interpreter_path = ctx.fragments.bazel_py.python_path
-        toolchain_runtime, effective_runtime = _maybe_get_runtime_from_ctx(ctx)
-        if not effective_runtime:
-            # Clear these just in case
-            toolchain_runtime = None
-            effective_runtime = None
-
-    else:  # Google code path
-        flag_interpreter_path = None
-        toolchain_runtime, effective_runtime = _maybe_get_runtime_from_ctx(ctx)
-        if not effective_runtime:
-            fail("Unable to find Python runtime")
+    flag_interpreter_path = ctx.fragments.bazel_py.python_path
+    toolchain_runtime, effective_runtime = _maybe_get_runtime_from_ctx(ctx)
+    if not effective_runtime:
+        # Clear these just in case
+        toolchain_runtime = None
+        effective_runtime = None
 
     if effective_runtime:
         direct = []  # List of files
@@ -1207,7 +1193,7 @@ def _maybe_get_runtime_from_ctx(ctx):
         effective_runtime = toolchain_runtime
     else:
         toolchain_runtime = None
-        attr_target = getattr(ctx.attr, PY_RUNTIME_ATTR_NAME)
+        attr_target = ctx.attr._py_interpreter
 
         # In Bazel, --python_top is null by default.
         if attr_target and PyRuntimeInfo in attr_target:
@@ -1335,9 +1321,9 @@ def _create_runfiles_with_build_data(
         central_uncachable_version_file,
         extra_write_build_data_env,
     )
-    build_data_runfiles = ctx.runfiles(symlinks = {
-        BUILD_DATA_SYMLINK_PATH: build_data_file,
-    })
+    build_data_runfiles = ctx.runfiles(files = [
+        build_data_file,
+    ])
     return build_data_file, build_data_runfiles
 
 def _write_build_data(ctx, central_uncachable_version_file, extra_write_build_data_env):
@@ -1552,7 +1538,7 @@ def determine_main(ctx):
     """
     if ctx.attr.main:
         proposed_main = ctx.attr.main.label.name
-        if not proposed_main.endswith(tuple(ALLOWED_MAIN_EXTENSIONS)):
+        if not proposed_main.endswith(".py"):
             fail("main must end in '.py'")
     else:
         if ctx.label.name.endswith(".py"):