Track whether a repo is pinned or unpinned by explicit attr (bazel-co…

…ntrib#1204)

* Factor detecting whether repo is unpinned into a shared helper

* Track whether a repo is pinned or unpinned by explicit attr

Doing this by performing string interpretation on the repo name is a bit
brittle. And it works less well under Bzlmod where the unpinned repo
name is going to look something like
`rules_jvm_external~~maven~unpinned_maven`.

After this change, the lockfile pinning script, `@maven//:pin` will use the local
machine's Coursier cache (`~/Library/Caches/Coursier` on MacOS) even under
Bzlmod. A populated cache makes version resolutions substantially faster to obtain.

* Fix errant tab in indentation

Tab added by misconfigured editor.

private/extensions/maven.bzl

@@ -412,6 +412,7 @@ def _maven_impl(mctx):
                 # created from the maven_install.json file in the coursier_fetch
                 # invocation after this.
                 name = "unpinned_" + name if repo.get("lock_file") else name,
+                pinned_repo_name = name if repo.get("lock_file") else None,
                 user_provided_name = name,
                 repositories = repo.get("repositories"),
                 artifacts = artifacts_json,

private/rules/coursier.bzl

@@ -137,6 +137,9 @@ def _is_file(repository_ctx, path):
 def _is_directory(repository_ctx, path):
     return repository_ctx.which("test") and repository_ctx.execute(["test", "-d", path]).return_code == 0
 
+def _is_unpinned(repository_ctx):
+    return repository_ctx.attr.pinned_repo_name != ""
+
 def _shell_quote(s):
     # Lifted from
     #   https://github.com/bazelbuild/bazel-skylib/blob/6a17363a3c27dde70ab5002ad9f2e29aff1e1f4b/lib/shell.bzl#L49
@@ -875,7 +878,7 @@ def make_coursier_dep_tree(
         cmd.append("--default=true")
 
     environment = {}
-    if not repository_ctx.attr.name.startswith("unpinned_"):
+    if not _is_unpinned(repository_ctx):
         coursier_cache_location = get_coursier_cache_or_default(
             repository_ctx,
             False,
@@ -1009,7 +1012,7 @@ def _coursier_fetch_impl(repository_ctx):
     # TODO(jin): allow custom cache locations
     coursier_cache_path = get_coursier_cache_or_default(
         repository_ctx,
-        repository_ctx.attr.name.startswith("unpinned_"),
+        _is_unpinned(repository_ctx),
     ).replace("//", "/")
 
     for artifact in dep_tree["dependencies"]:
@@ -1032,13 +1035,13 @@ def _coursier_fetch_impl(repository_ctx):
             #    to file within the repository rule workspace
             print("Assuming maven local for artifact: %s" % artifact["coord"])
             artifact.update({"url": None})
-            if not repository_ctx.attr.name.startswith("unpinned_"):
+            if not _is_unpinned(repository_ctx):
                 artifact.update({"file": _relativize_and_symlink_file_in_maven_local(repository_ctx, artifact["file"])})
 
             files_to_inspect.append(repository_ctx.path(artifact["file"]))
             continue
 
-        if repository_ctx.attr.name.startswith("unpinned_"):
+        if _is_unpinned(repository_ctx):
             artifact.update({"file": _relativize_and_symlink_file_in_coursier_cache(repository_ctx, artifact["file"], coursier_cache_path)})
 
         # Coursier saves the artifacts into a subdirectory structure
@@ -1231,13 +1234,13 @@ def _coursier_fetch_impl(repository_ctx):
         },
         override_targets = repository_ctx.attr.override_targets,
         # Skip maven local dependencies if generating the unpinned repository
-        skip_maven_local_dependencies = repository_ctx.attr.name.startswith("unpinned_"),
+        skip_maven_local_dependencies = _is_unpinned(repository_ctx),
     )
 
     # This repository rule can be either in the pinned or unpinned state, depending on when
     # the user invokes artifact pinning. Normalize the repository name here.
-    if repository_ctx.name.startswith("unpinned_"):
-        repository_name = repository_ctx.name[len("unpinned_"):]
+    if _is_unpinned(repository_ctx):
+        repository_name = repository_ctx.attr.pinned_repo_name
         outdated_build_file_content = ""
     else:
         repository_name = repository_ctx.name
@@ -1439,6 +1442,10 @@ coursier_fetch = repository_rule(
         ),
         "ignore_empty_files": attr.bool(default = False, doc = "Treat jars that are empty as if they were not found."),
         "additional_coursier_options": attr.string_list(doc = "Additional options that will be passed to coursier."),
+        "pinned_repo_name": attr.string(
+            doc = "Name of the corresponding pinned repo for this repo. Presence implies that this is an unpinned repo.",
+            mandatory = False,
+        ),
     },
     environ = [
         "JAVA_HOME",

private/rules/maven_install.bzl

@@ -123,6 +123,7 @@ def maven_install(
             # created from the maven_install.json file in the coursier_fetch
             # invocation after this.
             name = name if maven_install_json == None else "unpinned_" + name,
+            pinned_repo_name = None if maven_install_json == None else name,
             repositories = repositories_json_strings,
             artifacts = artifacts_json_strings,
             fail_on_missing_checksum = fail_on_missing_checksum,