Withdraw modules functions bazed on bazelbuild#548

Based @fmeum's review comments on bazelbuild#548, removed the following functions
from `lib/modules.bzl`:

- `adjust_main_repo_prefix`: prefer solutions based on
  `attr.label_list`, `Label`, and `native.package_relative_label` to
  pass `Label` values in the code

- `is_bzlmod_enabled`: available in `@bazel_features`, only added
  because of `repo_name`

- `repo_name`: replaced with a `getattr` + `hasattr` expression, since
  Bazel 5 is near end of life and it's easier to search and replace this
  expression

Author: mbland

docs/modules_doc.md

@@ -2,35 +2,6 @@
 
 Skylib module containing utilities for Bazel modules and module extensions.
 
-<a id="modules.adjust_main_repo_prefix"></a>
-
-## modules.adjust_main_repo_prefix
-
-<pre>
-modules.adjust_main_repo_prefix(<a href="#modules.adjust_main_repo_prefix-target_pattern">target_pattern</a>)
-</pre>
-
-Updates the main repository prefix to match the current Bazel version.
-
-The main repo prefix will be "@//" for Bazel < 7.1.0, and "@@//" for Bazel
->= 7.1.0 under Bzlmod. This macro automatically updates strings representing
-include/exclude target patterns so that they match actual main repository
-target Labels correctly.
-
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="modules.adjust_main_repo_prefix-target_pattern"></a>target_pattern |  a string used to match a BUILD target pattern   |  none |
-
-**RETURNS**
-
-the string with any main repository prefix updated to match the current
-      Bazel version
-
-
 <a id="modules.apparent_repo_label_string"></a>
 
 ## modules.apparent_repo_label_string
@@ -112,33 +83,6 @@ imported via `use_repo`. The extension is marked as reproducible if supported by
 version of Bazel and thus doesn't result in a lockfile entry.
 
 
-<a id="modules.repo_name"></a>
-
-## modules.repo_name
-
-<pre>
-modules.repo_name(<a href="#modules.repo_name-label_or_name">label_or_name</a>)
-</pre>
-
-Utility to provide Label compatibility with Bazel 5.
-
-Under Bazel 5, calls `Label.workspace_name`. Otherwise calls
-`Label.repo_name`.
-
-
-**PARAMETERS**
-
-
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="modules.repo_name-label_or_name"></a>label_or_name |  a Label or repository name string   |  none |
-
-**RETURNS**
-
-The repository name returned directly from the Label API, or the
-      original string if not a Label
-
-
 <a id="modules.use_all_repos"></a>
 
 ## modules.use_all_repos

lib/modules.bzl

@@ -114,23 +114,9 @@ def _use_all_repos(module_ctx, reproducible = False):
         **extension_metadata_kwargs
     )
 
-def _repo_name(label_or_name):
-    """Utility to provide Label compatibility with Bazel 5.
-
-    Under Bazel 5, calls `Label.workspace_name`. Otherwise calls
-    `Label.repo_name`.
-
-    Args:
-        label_or_name: a Label or repository name string
-
-    Returns:
-        The repository name returned directly from the Label API, or the
-            original string if not a Label
-    """
-    if hasattr(label_or_name, "repo_name"):
-        return label_or_name.repo_name
-
-    return getattr(label_or_name, "workspace_name", label_or_name)
+_repo_attr = (
+    "repo_name" if hasattr(Label("//:all"), "repo_name") else "workspace_name"
+)
 
 def _apparent_repo_name(label_or_name):
     """Return a repository's apparent repository name.
@@ -141,7 +127,7 @@ def _apparent_repo_name(label_or_name):
     Returns:
         The apparent repository name
     """
-    repo_name = _repo_name(label_or_name).lstrip("@")
+    repo_name = getattr(label_or_name, _repo_attr, label_or_name).lstrip("@")
     delimiter_indices = []
 
     # Bazed on this pattern from the Bazel source:
@@ -171,44 +157,16 @@ def _apparent_repo_label_string(label):
         str(label) with its canonical repository name replaced with its apparent
             repository name
     """
-    repo_name = _repo_name(label)
+    repo_name = getattr(label, _repo_attr).lstrip("@")
     if len(repo_name) == 0:
         return str(label)
 
     label_str = "@" + str(label).lstrip("@")
     return label_str.replace(repo_name, _apparent_repo_name(label))
 
-_is_bzlmod_enabled = str(Label("//:all")).startswith("@@")
-
-_main_repo_prefix = "@@//" if _is_bzlmod_enabled else "@//"
-
-def _adjust_main_repo_prefix(target_pattern):
-    """Updates the main repository prefix to match the current Bazel version.
-
-    The main repo prefix will be "@//" for Bazel < 7.1.0, and "@@//" for Bazel
-    >= 7.1.0 under Bzlmod. This macro automatically updates strings representing
-    include/exclude target patterns so that they match actual main repository
-    target Labels correctly.
-
-    Args:
-        target_pattern: a string used to match a BUILD target pattern
-
-    Returns:
-        the string with any main repository prefix updated to match the current
-            Bazel version
-    """
-    if target_pattern.startswith("@//") or target_pattern.startswith("@@//"):
-        return _main_repo_prefix + target_pattern.lstrip("@/")
-
-    return target_pattern
-
 modules = struct(
     as_extension = _as_extension,
     use_all_repos = _use_all_repos,
-    repo_name = _repo_name,
     apparent_repo_name = _apparent_repo_name,
     apparent_repo_label_string = _apparent_repo_label_string,
-    is_bzlmod_enabled = _is_bzlmod_enabled,
-    main_repo_prefix = _main_repo_prefix,
-    adjust_main_repo_prefix = _adjust_main_repo_prefix,
 )

tests/modules_test.bzl

@@ -18,6 +18,8 @@ load("//lib:modules.bzl", "modules")
 load("//lib:unittest.bzl", "asserts", "unittest")
 load("//rules:build_test.bzl", "build_test")
 
+_is_bzlmod_enabled = str(Label("//tests:module_tests.bzl")).startswith("@@")
+
 def _repo_rule_impl(repository_ctx):
     repository_ctx.file("WORKSPACE")
     repository_ctx.file("BUILD", """exports_files(["hello"])""")
@@ -73,10 +75,15 @@ def _apparent_repo_name_test(ctx):
         msg = "Return the original name without `@` if already apparent.",
     )
 
+    foo_label = Label("@foo")
+    foo_canonical_name = getattr(
+        foo_label,
+        "repo_name" if hasattr(foo_label, "repo_name") else "workspace_name",
+    )
     asserts.equals(
         env,
         "foo",
-        modules.apparent_repo_name(modules.repo_name(Label("@foo"))),
+        modules.apparent_repo_name(foo_canonical_name),
         msg = "Return the apparent name from a canonical name string.",
     )
 
@@ -117,7 +124,7 @@ def _apparent_repo_name_test(ctx):
 
     asserts.equals(
         env,
-        "stardoc" if modules.is_bzlmod_enabled else "io_bazel_stardoc",
+        "stardoc" if _is_bzlmod_enabled else "io_bazel_stardoc",
         modules.apparent_repo_name(Label("@io_bazel_stardoc")),
         msg = " ".join([
             "Label values will already map bazel_dep repo_names to",
@@ -170,7 +177,7 @@ def _apparent_repo_label_string_test(ctx):
     asserts.equals(
         env,
         "@%s//:all" % (
-            "stardoc" if modules.is_bzlmod_enabled else "io_bazel_stardoc"
+            "stardoc" if _is_bzlmod_enabled else "io_bazel_stardoc"
         ),
         modules.apparent_repo_label_string(Label("@io_bazel_stardoc//:all")),
         msg = " ".join([
@@ -185,39 +192,6 @@ apparent_repo_label_string_test = unittest.make(
     _apparent_repo_label_string_test,
 )
 
-def _adjust_main_repo_prefix_test(ctx):
-    """Unit tests for modules.apparent_repo_label_string."""
-    env = unittest.begin(ctx)
-
-    expected = modules.main_repo_prefix + ":all"
-    asserts.equals(
-        env,
-        expected,
-        modules.adjust_main_repo_prefix("@//:all"),
-        msg = "Normalizes a target pattern starting with `@//`.",
-    )
-
-    asserts.equals(
-        env,
-        expected,
-        modules.adjust_main_repo_prefix("@@//:all"),
-        msg = "Normalizes a target pattern starting with `@@//`.",
-    )
-
-    original = "@not_the_main_repo"
-    asserts.equals(
-        env,
-        original,
-        modules.adjust_main_repo_prefix(original),
-        msg = "Returns non main repo target patterns unchanged.",
-    )
-
-    return unittest.end(env)
-
-adjust_main_repo_prefix_test = unittest.make(
-    _adjust_main_repo_prefix_test,
-)
-
 # buildifier: disable=unnamed-macro
 def modules_test_suite():
     """Creates the tests for modules.bzl if Bzlmod is enabled."""
@@ -226,10 +200,9 @@ def modules_test_suite():
         "modules_tests",
         apparent_repo_name_test,
         apparent_repo_label_string_test,
-        adjust_main_repo_prefix_test,
     )
 
-    if not modules.is_bzlmod_enabled:
+    if not _is_bzlmod_enabled:
         return
 
     build_test(