[bzlmod] Allow compat repos to be generated

MODULE.bazel

@@ -4,17 +4,15 @@ module(
 )
 
 bazel_dep(name = "bazel_skylib", version = "1.4.1")
-bazel_dep(name = "stardoc", repo_name = "io_bazel_stardoc", version = "0.5.3")
+bazel_dep(name = "stardoc", version = "0.5.3", repo_name = "io_bazel_stardoc")
 
 non_module_deps = use_extension("//:non-module-deps.bzl", "non_module_deps")
-
 use_repo(
     non_module_deps,
     "io_bazel_rules_kotlin",
 )
 
 maven = use_extension(":extensions.bzl", "maven")
-
 maven.install(
     name = "rules_jvm_external_deps",
     artifacts = [
@@ -30,7 +28,6 @@ maven.install(
     ],
     lock_file = "@rules_jvm_external//:rules_jvm_external_deps_install.json",
 )
-
 use_repo(
     maven,
     "rules_jvm_external_deps",

WORKSPACE

@@ -351,11 +351,11 @@ maven_install(
         # Must not be in any other maven_install where generate_compat_repositories = True
         "com.google.http-client:google-http-client-gson:1.42.3",
     ],
+    generate_compat_repositories = True,
     repositories = [
         "https://repo1.maven.org/maven2",
     ],
     strict_visibility = True,
-    generate_compat_repositories = True,
 )
 
 load("@strict_visibility_with_compat_testing//:compat.bzl", "compat_repositories")

private/compat_repository.bzl

@@ -15,11 +15,13 @@ alias(
 """
 
 def _compat_repository_impl(repository_ctx):
+    target_name = repository_ctx.attr.target_name if repository_ctx.attr.target_name else repository_ctx.name
+
     repository_ctx.file(
         "jar/BUILD",
         _JAR_BUILD.format(
             generating_repository = repository_ctx.attr.generating_repository,
-            target_name = repository_ctx.name,
+            target_name = target_name,
         ),
         executable = False,
     )
@@ -29,7 +31,7 @@ def _compat_repository_impl(repository_ctx):
         _ROOT_BUILD.format(
             repository_name = repository_ctx.name,
             generating_repository = repository_ctx.attr.generating_repository,
-            target_name = repository_ctx.name,
+            target_name = target_name,
         ),
         executable = False,
     )
@@ -38,5 +40,6 @@ compat_repository = repository_rule(
     implementation = _compat_repository_impl,
     attrs = {
         "generating_repository": attr.string(default = "maven"),
+        "target_name": attr.string(),
     },
 )

private/extensions/maven.bzl

@@ -1,3 +1,5 @@
+load("//private:compat_repository.bzl", "compat_repository")
+load("//private:coursier_utilities.bzl", "escape")
 load("//private:dependency_tree_parser.bzl", "JETIFY_INCLUDE_LIST_JETIFY_ALL")
 load("//private/rules:v1_lock_file.bzl", "v1_lock_file")
 load("//private/rules:v2_lock_file.bzl", "v2_lock_file")
@@ -74,6 +76,9 @@ _install = tag_class(
         "fail_if_repin_required": attr.bool(doc = "Whether to fail the build if the maven_artifact inputs have changed but the lock file has not been repinned.", default = False),
         "lock_file": attr.label(),
         "repositories": attr.string_list(default = DEFAULT_REPOSITORIES),
+        "generate_compat_repositories": attr.bool(
+            doc = "Additionally generate repository aliases in a .bzl file for all JAR artifacts. For example, `@maven//:com_google_guava_guava` can also be referenced as `@com_google_guava_guava//jar`.",
+        ),
 
         # When using an unpinned repo
         "excluded_artifacts": attr.string_list(doc = "Artifacts to exclude, in `artifactId:groupId` format. Only used on unpinned installs", default = []),  # list of artifacts to exclude
@@ -155,6 +160,7 @@ def _maven_impl(mctx):
     # - fail_on_missing_checksum: bool. A logical OR over all `fail_on_missing_checksum` for all `install` tags with the same name.
     # - fetch_javadoc: bool. A logical OR over all `fetch_javadoc` for all `install` tags with the same name.
     # - fetch_sources: bool. A logical OR over all `fetch_sources` for all `install` tags with the same name.
+    # - generate_compat_repositories: bool. A logical OR over all `generate_compat_repositories` for all `install` tags with the same name.
     # - jetify: bool. A logical OR over all `jetify` for all `install` tags with the same name.
     # - jetify_include_list: string list. Accumulated from all `install` tags
     # - lock_file: the lock file to use, if present. Multiple lock files will cause the build to fail.
@@ -242,6 +248,7 @@ def _maven_impl(mctx):
             _logical_or(repo, "fail_on_missing_checksum", False, install.fail_on_missing_checksum)
             _logical_or(repo, "fetch_sources", False, install.fetch_sources)
             _logical_or(repo, "fetch_javadoc", False, install.fetch_javadoc)
+            _logical_or(repo, "generate_compat_repositories", False, install.generate_compat_repositories)
             _logical_or(repo, "jetify", False, install.jetify)
             _logical_or(repo, "strict_visibility", False, install.strict_visibility)
             _logical_or(repo, "use_starlark_android_rules", False, install.use_starlark_android_rules)
@@ -322,6 +329,19 @@ def _maven_impl(mctx):
             duplicate_version_warning = repo.get("duplicate_version_warning"),
         )
 
+        if repo.get("generate_compat_repositories"):
+            seen = []
+            for artifact in artifacts:
+                versionless = escape(artifact["group"] + "_" + artifact["artifact"])
+                if versionless in seen:
+                    continue
+                seen.append(versionless)
+                compat_repository(
+                    name = versionless,
+                    generating_repository = name,
+                    target_name = versionless,
+                )
+
         if repo.get("lock_file"):
             lock_file = json.decode(mctx.read(mctx.path(repo.get("lock_file"))))