refactor: consolidate py_executable_bazel, common_bazel (bazel-contrib#2523)

This furthers the work of removing the artificial split of code that
stemmed from
when the implementation was part of Bazel itself. Summary of changes:

* Move most of `py_executable_bazel.bzl` into `py_executable.bzl`
* Move most of `common_bazel.bzl` into `common.bzl`
* Create `precompile.bzl` for the precompile helpers. This is to avoid a
  circular dependency between common.bzl and attributes.bzl.

Work towards bazel-contrib#2522

Author: rickeylev

python/private/BUILD.bazel

@@ -104,30 +104,18 @@ bzl_library(
     deps = [":py_internal_bzl"],
 )
 
-bzl_library(
-    name = "common_bazel_bzl",
-    srcs = ["common_bazel.bzl"],
-    deps = [
-        ":attributes_bzl",
-        ":common_bzl",
-        ":py_cc_link_params_info_bzl",
-        ":py_internal_bzl",
-        ":py_interpreter_program_bzl",
-        ":toolchain_types_bzl",
-        "@bazel_skylib//lib:paths",
-    ],
-)
-
 bzl_library(
     name = "common_bzl",
     srcs = ["common.bzl"],
     deps = [
         ":cc_helper_bzl",
+        ":py_cc_link_params_info_bzl",
         ":py_info_bzl",
         ":py_internal_bzl",
         ":reexports_bzl",
         ":rules_cc_srcs_bzl",
         ":semantics_bzl",
+        "@bazel_skylib//lib:paths",
     ],
 )
 
@@ -199,6 +187,18 @@ bzl_library(
     srcs = ["normalize_name.bzl"],
 )
 
+bzl_library(
+    name = "precompile_bzl",
+    srcs = ["precompile.bzl"],
+    deps = [
+        ":attributes_bzl",
+        ":py_internal_bzl",
+        ":py_interpreter_program_bzl",
+        ":toolchain_types_bzl",
+        "@bazel_skylib//lib:paths",
+    ],
+)
+
 bzl_library(
     name = "python_bzl",
     srcs = ["python.bzl"],
@@ -265,8 +265,8 @@ bzl_library(
     name = "py_binary_macro_bzl",
     srcs = ["py_binary_macro.bzl"],
     deps = [
-        ":common_bzl",
         ":py_binary_rule_bzl",
+        ":py_executable_bzl",
     ],
 )
 
@@ -275,7 +275,7 @@ bzl_library(
     srcs = ["py_binary_rule.bzl"],
     deps = [
         ":attributes_bzl",
-        ":py_executable_bazel_bzl",
+        ":py_executable_bzl",
         ":semantics_bzl",
         "@bazel_skylib//lib:dicts",
     ],
@@ -343,20 +343,6 @@ bzl_library(
     ],
 )
 
-bzl_library(
-    name = "py_executable_bazel_bzl",
-    srcs = ["py_executable_bazel.bzl"],
-    deps = [
-        ":attributes_bzl",
-        ":common_bazel_bzl",
-        ":common_bzl",
-        ":py_executable_bzl",
-        ":py_internal_bzl",
-        ":py_runtime_info_bzl",
-        ":semantics_bzl",
-    ],
-)
-
 bzl_library(
     name = "py_executable_bzl",
     srcs = ["py_executable.bzl"],
@@ -365,6 +351,7 @@ bzl_library(
         ":cc_helper_bzl",
         ":common_bzl",
         ":flags_bzl",
+        ":precompile_bzl",
         ":py_cc_link_params_info_bzl",
         ":py_executable_info_bzl",
         ":py_info_bzl",
@@ -373,6 +360,7 @@ bzl_library(
         ":rules_cc_srcs_bzl",
         ":toolchain_types_bzl",
         "@bazel_skylib//lib:dicts",
+        "@bazel_skylib//lib:paths",
         "@bazel_skylib//lib:structs",
         "@bazel_skylib//rules:common_settings",
     ],
@@ -431,8 +419,8 @@ bzl_library(
     name = "py_library_rule_bzl",
     srcs = ["py_library_rule.bzl"],
     deps = [
-        ":common_bazel_bzl",
         ":common_bzl",
+        ":precompile_bzl",
         ":py_library_bzl",
     ],
 )
@@ -508,7 +496,7 @@ bzl_library(
     name = "py_test_macro_bzl",
     srcs = ["py_test_macro.bzl"],
     deps = [
-        ":common_bazel_bzl",
+        ":py_executable_bzl",
         ":py_test_rule_bzl",
     ],
 )
@@ -519,7 +507,7 @@ bzl_library(
     deps = [
         ":attributes_bzl",
         ":common_bzl",
-        ":py_executable_bazel_bzl",
+        ":py_executable_bzl",
         ":semantics_bzl",
         "@bazel_skylib//lib:dicts",
     ],

python/private/common.bzl

@@ -11,9 +11,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-"""Various things common to Bazel and Google rule implementations."""
+"""Various things common to rule implementations."""
 
+load("@bazel_skylib//lib:paths.bzl", "paths")
+load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
+load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load(":cc_helper.bzl", "cc_helper")
+load(":py_cc_link_params_info.bzl", "PyCcLinkParamsInfo")
 load(":py_info.bzl", "PyInfo", "PyInfoBuilder")
 load(":py_internal.bzl", "py_internal")
 load(":reexports.bzl", "BuiltinPyInfo")
@@ -262,6 +266,30 @@ def filter_to_py_srcs(srcs):
     # as a valid extension.
     return [f for f in srcs if f.extension == "py"]
 
+def collect_cc_info(ctx, extra_deps = []):
+    """Collect C++ information from dependencies for Bazel.
+
+    Args:
+        ctx: Rule ctx; must have `deps` attribute.
+        extra_deps: list of Target to also collect C+ information from.
+
+    Returns:
+        CcInfo provider of merged information.
+    """
+    deps = ctx.attr.deps
+    if extra_deps:
+        deps = list(deps)
+        deps.extend(extra_deps)
+    cc_infos = []
+    for dep in deps:
+        if CcInfo in dep:
+            cc_infos.append(dep[CcInfo])
+
+        if PyCcLinkParamsInfo in dep:
+            cc_infos.append(dep[PyCcLinkParamsInfo].cc_info)
+
+    return cc_common.merge_cc_infos(cc_infos = cc_infos)
+
 def collect_imports(ctx, semantics):
     """Collect the direct and transitive `imports` strings.
 
@@ -280,6 +308,37 @@ def collect_imports(ctx, semantics):
             transitive.append(dep[BuiltinPyInfo].imports)
     return depset(direct = semantics.get_imports(ctx), transitive = transitive)
 
+def get_imports(ctx):
+    """Gets the imports from a rule's `imports` attribute.
+
+    See create_binary_semantics_struct for details about this function.
+
+    Args:
+        ctx: Rule ctx.
+
+    Returns:
+        List of strings.
+    """
+    prefix = "{}/{}".format(
+        ctx.workspace_name,
+        py_internal.get_label_repo_runfiles_path(ctx.label),
+    )
+    result = []
+    for import_str in ctx.attr.imports:
+        import_str = ctx.expand_make_variables("imports", import_str, {})
+        if import_str.startswith("/"):
+            continue
+
+        # To prevent "escaping" out of the runfiles tree, we normalize
+        # the path and ensure it doesn't have up-level references.
+        import_path = paths.normalize("{}/{}".format(prefix, import_str))
+        if import_path.startswith("../") or import_path == "..":
+            fail("Path '{}' references a path above the execution root".format(
+                import_str,
+            ))
+        result.append(import_path)
+    return result
+
 def collect_runfiles(ctx, files = depset()):
     """Collects the necessary files from the rule's context.
 

python/private/common_bazel.bzl renamed to python/private/precompile.bzl

@@ -13,44 +13,12 @@
 # limitations under the License.
 """Common functions that are specific to Bazel rule implementation"""
 
-load("@bazel_skylib//lib:paths.bzl", "paths")
 load("@bazel_skylib//rules:common_settings.bzl", "BuildSettingInfo")
-load("@rules_cc//cc/common:cc_common.bzl", "cc_common")
-load("@rules_cc//cc/common:cc_info.bzl", "CcInfo")
 load(":attributes.bzl", "PrecompileAttr", "PrecompileInvalidationModeAttr", "PrecompileSourceRetentionAttr")
-load(":common.bzl", "is_bool")
 load(":flags.bzl", "PrecompileFlag")
-load(":py_cc_link_params_info.bzl", "PyCcLinkParamsInfo")
-load(":py_internal.bzl", "py_internal")
 load(":py_interpreter_program.bzl", "PyInterpreterProgramInfo")
 load(":toolchain_types.bzl", "EXEC_TOOLS_TOOLCHAIN_TYPE", "TARGET_TOOLCHAIN_TYPE")
 
-_py_builtins = py_internal
-
-def collect_cc_info(ctx, extra_deps = []):
-    """Collect C++ information from dependencies for Bazel.
-
-    Args:
-        ctx: Rule ctx; must have `deps` attribute.
-        extra_deps: list of Target to also collect C+ information from.
-
-    Returns:
-        CcInfo provider of merged information.
-    """
-    deps = ctx.attr.deps
-    if extra_deps:
-        deps = list(deps)
-        deps.extend(extra_deps)
-    cc_infos = []
-    for dep in deps:
-        if CcInfo in dep:
-            cc_infos.append(dep[CcInfo])
-
-        if PyCcLinkParamsInfo in dep:
-            cc_infos.append(dep[PyCcLinkParamsInfo].cc_info)
-
-    return cc_common.merge_cc_infos(cc_infos = cc_infos)
-
 def maybe_precompile(ctx, srcs):
     """Computes all the outputs (maybe precompiled) from the input srcs.
 
@@ -237,44 +205,3 @@ def _precompile(ctx, src, *, use_pycache):
         toolchain = EXEC_TOOLS_TOOLCHAIN_TYPE,
     )
     return pyc
-
-def get_imports(ctx):
-    """Gets the imports from a rule's `imports` attribute.
-
-    See create_binary_semantics_struct for details about this function.
-
-    Args:
-        ctx: Rule ctx.
-
-    Returns:
-        List of strings.
-    """
-    prefix = "{}/{}".format(
-        ctx.workspace_name,
-        _py_builtins.get_label_repo_runfiles_path(ctx.label),
-    )
-    result = []
-    for import_str in ctx.attr.imports:
-        import_str = ctx.expand_make_variables("imports", import_str, {})
-        if import_str.startswith("/"):
-            continue
-
-        # To prevent "escaping" out of the runfiles tree, we normalize
-        # the path and ensure it doesn't have up-level references.
-        import_path = paths.normalize("{}/{}".format(prefix, import_str))
-        if import_path.startswith("../") or import_path == "..":
-            fail("Path '{}' references a path above the execution root".format(
-                import_str,
-            ))
-        result.append(import_path)
-    return result
-
-def convert_legacy_create_init_to_int(kwargs):
-    """Convert "legacy_create_init" key to int, in-place.
-
-    Args:
-        kwargs: The kwargs to modify. The key "legacy_create_init", if present
-            and bool, will be converted to its integer value, in place.
-    """
-    if is_bool(kwargs.get("legacy_create_init")):
-        kwargs["legacy_create_init"] = 1 if kwargs["legacy_create_init"] else 0

python/private/py_binary_macro.bzl

@@ -13,8 +13,8 @@
 # limitations under the License.
 """Implementation of macro-half of py_binary rule."""
 
-load(":common_bazel.bzl", "convert_legacy_create_init_to_int")
 load(":py_binary_rule.bzl", py_binary_rule = "py_binary")
+load(":py_executable.bzl", "convert_legacy_create_init_to_int")
 
 def py_binary(**kwargs):
     convert_legacy_create_init_to_int(kwargs)

python/private/py_binary_rule.bzl

@@ -16,9 +16,9 @@
 load("@bazel_skylib//lib:dicts.bzl", "dicts")
 load(":attributes.bzl", "AGNOSTIC_BINARY_ATTRS")
 load(
-    ":py_executable_bazel.bzl",
+    ":py_executable.bzl",
     "create_executable_rule",
-    "py_executable_bazel_impl",
+    "py_executable_impl",
 )
 
 _PY_TEST_ATTRS = {
@@ -39,7 +39,7 @@ _PY_TEST_ATTRS = {
 }
 
 def _py_binary_impl(ctx):
-    return py_executable_bazel_impl(
+    return py_executable_impl(
         ctx = ctx,
         is_test = False,
         inherited_environment = [],