Import jsinterop_annotations as a JAR only rather than the full java_library

PiperOrigin-RevId: 544347579

Author: kevinoconnor7

java/jsinterop/annotations/BUILD

@@ -3,6 +3,7 @@
 #
 
 load("@com_google_j2cl//build_defs:rules.bzl", "j2cl_import")
+load(":import_annotations_jar.bzl", "import_annotations_jar")
 load("@bazel_common_javadoc//:javadoc.bzl", "javadoc_library")
 
 package(
@@ -17,6 +18,17 @@ java_library(
     srcs = glob(["*.java"]),
 )
 
+# Re-import only the output jar, dropping all transitive dependencies in the
+# process. This is important for JsInterop Annotations as these are used by
+# the J2CL-emulated JRE itself and thus cannot have any dependencies outside of
+# toolchain's bootclasspath.
+import_annotations_jar(
+    name = "annotations_jar",
+    jar = ":libannotations.jar",
+    # No one outside of this package should _ever_ depend upon this target.
+    visibility = ["//visibility:private"],
+)
+
 javadoc_library(
     name = "annotations-javadoc",
     srcs = glob(["*.java"]),
@@ -28,5 +40,5 @@ javadoc_library(
 
 j2cl_import(
     name = "annotations-j2cl",
-    jar = ":annotations",
+    jar = ":annotations_jar",
 )

java/jsinterop/annotations/import_annotations_jar.bzl

@@ -0,0 +1,20 @@
+"""import_annotations_jar build macro
+
+This macro is intended for internal-use only to re-import the annotations JAR
+into a JavaInfo provider without keeping dependency information.
+"""
+
+def _impl_import_annotations_jar(ctx):
+    if ctx.file.jar.extension != "jar":
+        fail("jar must be a file with extension .jar")
+    return JavaInfo(output_jar = ctx.file.jar, compile_jar = ctx.file.jar)
+
+import_annotations_jar = rule(
+    implementation = _impl_import_annotations_jar,
+    attrs = {
+        "jar": attr.label(
+            allow_single_file = True,
+        ),
+    },
+    fragments = ["java"],
+)