Graal: [native-image] linking error when having java.lang.Thread in reflection config

[borkdude]

I have this in my reflection config:

{
    "name":"java.lang.Thread",
    "allPublicMethods":true,
    "allPublicFields": true,
    "allPublicConstructors": true
}

On macOS 10.14.6, GraalVM JDK 8 19.3.0 this fails with this output: https://github.com/borkdude/babashka/issues/121

Relevant parts:

Undefined symbols for architecture x86_64:
  "_Java_java_lang_Thread_countStackFrames", referenced from:
      ___svm_version_info in bb.o
ld: symbol(s) not found for architecture x86_64

Undefined symbols for architecture x86_64:
  "_Java_java_lang_Thread_countStackFrames", referenced from:
      ___svm_version_info in bb.o
ld: symbol(s) not found for architecture x86_64

It seems GraalVM is making deprecated methods reachable using this config, which then makes the linker fail.

I can work around the issue by enumerating things myself. I'm making a scripting environment where I use reflection to evaluate calls to a selected number of classes, that's why I need this and it's very convenient to not have to enumerate all methods explicitly.

[christianwimmer]

As stated in the issue, the workaround for the GraalVM 19.3 release and earlier is to not register all public methods of java.lang.Thread for reflection.

[dmlloyd]

An alternative workaround is to pre-index the reflection members that you need during static init, and stick them in a map or whatever you need; then you can look them up from there at run time.

[borkdude]

Generating the JSON for all the method names is relatively easy from Clojure:

;; invoke with: clojure -Sdeps '{:deps {cheshire {:mvn/version "RELEASE"}}}' methods.clj <class>
;; where <class> is e.g. java.lang.Thread

(require '[cheshire.core :as cheshire])

(defn public-declared-method? [c m]
  (and (= c (.getDeclaringClass m))
       (not (.getAnnotation m Deprecated))))

(defn public-declared-method-names [c]
  (->> (.getMethods c)
       (keep (fn [m]
               (when (public-declared-method? c m)
                 {:name (.getName m)})) )
       (distinct )))

(def the-class
  (Class/forName (first *command-line-args*)))

(println
 (cheshire/generate-string (public-declared-method-names the-class)))

$ clojure -Sdeps '{:deps {cheshire {:mvn/version "RELEASE"}}}' methods.clj java.lang.Thread
[{"name":"run"},{"name":"toString"},{"name":"isInterrupted"},{"name":"currentThread"},{"name":"getName"},{"name":"join"},{"name":"getThreadGroup"},{"name":"getStackTrace"},{"name":"holdsLock"},{"name":"checkAccess"},{"name":"dumpStack"},{"name":"yield"},{"name":"setPriority"},{"name":"setDaemon"},{"name":"start"},{"name":"sleep"},{"name":"interrupt"},{"name":"interrupted"},{"name":"isAlive"},{"name":"getPriority"},{"name":"setName"},{"name":"activeCount"},{"name":"enumerate"},{"name":"isDaemon"},{"name":"getContextClassLoader"},{"name":"setContextClassLoader"},{"name":"getAllStackTraces"},{"name":"getId"},{"name":"getState"},{"name":"setDefaultUncaughtExceptionHandler"},{"name":"getDefaultUncaughtExceptionHandler"},{"name":"getUncaughtExceptionHandler"},{"name":"setUncaughtExceptionHandler"}]