move the platform to a separate file

Author: aignas

python/private/pypi/BUILD.bazel

@@ -77,6 +77,7 @@ bzl_library(
     deps = [
         ":pep508_env_bzl",
         ":pep508_evaluate_bzl",
+        ":pep508_platform_bzl",
         ":pep508_requirement_bzl",
     ],
 )
@@ -226,6 +227,7 @@ bzl_library(
     deps = [
         ":pep508_env_bzl",
         ":pep508_evaluate_bzl",
+        ":pep508_platform_bzl",
         ":pep508_requirement_bzl",
         "//python/private:normalize_name_bzl",
     ],
@@ -234,6 +236,9 @@ bzl_library(
 bzl_library(
     name = "pep508_env_bzl",
     srcs = ["pep508_env.bzl"],
+    deps = [
+        ":pep508_platform_bzl",
+    ],
 )
 
 bzl_library(
@@ -245,6 +250,11 @@ bzl_library(
     ],
 )
 
+bzl_library(
+    name = "pep508_platform_bzl",
+    srcs = ["pep508_platform.bzl"],
+)
+
 bzl_library(
     name = "pep508_requirement_bzl",
     srcs = ["pep508_requirement.bzl"],

python/private/pypi/evaluate_markers.bzl

@@ -14,8 +14,9 @@
 
 """A simple function that evaluates markers using a python interpreter."""
 
-load(":pep508_env.bzl", "env", _platform_from_str = "platform_from_str")
+load(":pep508_env.bzl", "env")
 load(":pep508_evaluate.bzl", "evaluate")
+load(":pep508_platform.bzl", "platform_from_str")
 load(":pep508_requirement.bzl", "requirement")
 
 def evaluate_markers(requirements):
@@ -31,7 +32,7 @@ def evaluate_markers(requirements):
     for req_string, platforms in requirements.items():
         req = requirement(req_string)
         for platform in platforms:
-            if evaluate(req.marker, env = env(_platform_from_str(platform, None))):
+            if evaluate(req.marker, env = env(platform_from_str(platform, None))):
                 ret.setdefault(req_string, []).append(platform)
 
     return ret

python/private/pypi/pep508_deps.bzl

@@ -16,8 +16,9 @@
 """
 
 load("//python/private:normalize_name.bzl", "normalize_name")
-load(":pep508_env.bzl", "env", "platform", "platform_from_str")
+load(":pep508_env.bzl", "env")
 load(":pep508_evaluate.bzl", "evaluate")
+load(":pep508_platform.bzl", "platform", "platform_from_str")
 load(":pep508_requirement.bzl", "requirement")
 
 _ALL_OS_VALUES = [

python/private/pypi/pep508_env.bzl

@@ -15,6 +15,8 @@
 """This module is for implementing PEP508 environment definition.
 """
 
+load(":pep508_platform.bzl", "platform_from_str")
+
 # See https://stackoverflow.com/a/45125525
 _platform_machine_aliases = {
     # These pairs mean the same hardware, but different values may be used
@@ -116,31 +118,3 @@ def env(target_platform, *, extra = None):
             "platform_machine": _platform_machine_aliases,
         },
     }
-
-def platform(*, abi = None, os = None, arch = None):
-    return struct(
-        abi = abi,
-        os = os,
-        arch = arch,
-    )
-
-def platform_from_str(p, python_version):
-    """Return a platform from a string.
-
-    Args:
-        p: {type}`str` the actual string.
-        python_version: {type}`str` the python version to add to platform if needed.
-
-    Returns:
-        A struct that is returned by the `_platform` function.
-    """
-    if p.startswith("cp"):
-        abi, _, p = p.partition("_")
-    elif python_version:
-        major, _, tail = python_version.partition(".")
-        abi = "cp{}{}".format(major, tail)
-    else:
-        abi = None
-
-    os, _, arch = p.partition("_")
-    return platform(abi = abi, os = os or None, arch = arch or None)

python/private/pypi/pep508_platform.bzl

@@ -0,0 +1,44 @@
+# Copyright 2025 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+
+"""The platform abstraction
+"""
+
+def platform(*, abi = None, os = None, arch = None):
+    return struct(
+        abi = abi,
+        os = os,
+        arch = arch,
+    )
+
+def platform_from_str(p, python_version):
+    """Return a platform from a string.
+
+    Args:
+        p: {type}`str` the actual string.
+        python_version: {type}`str` the python version to add to platform if needed.
+
+    Returns:
+        A struct that is returned by the `_platform` function.
+    """
+    if p.startswith("cp"):
+        abi, _, p = p.partition("_")
+    elif python_version:
+        major, _, tail = python_version.partition(".")
+        abi = "cp{}{}".format(major, tail)
+    else:
+        abi = None
+
+    os, _, arch = p.partition("_")
+    return platform(abi = abi, os = os or None, arch = arch or None)