Description
In #4111 we tracked general Java 9 support, for running JRuby and associated apps and libraries.
This bug tracks the additional flags and cleanup we should do relating to accessibility warnings.
At a minimum, we need to audit all uses of reflection to "crack open" classes and find alternatives or consider --add-opens flags.
Here is the list of illegal accesses we do while running gem install rails:
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/Users/headius/projects/jruby/lib/ruby/stdlib/jopenssl.jar) to constructor java.security.cert.CertificateFactory(java.security.cert.CertificateFactorySpi,java.security.Provider,java.lang.String)
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/Users/headius/projects/jruby/lib/ruby/stdlib/jopenssl.jar) to field java.security.MessageDigest.provider
WARNING: Illegal reflective access by org.jruby.ext.zlib.RubyZlib to field java.util.zip.CRC32.crc
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/Users/headius/projects/jruby/lib/ruby/stdlib/jopenssl.jar) to constructor java.security.cert.CertificateFactory(java.security.cert.CertificateFactorySpi,java.security.Provider,java.lang.String)
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/Users/headius/projects/jruby/lib/ruby/stdlib/jopenssl.jar) to constructor java.security.cert.CertificateFactory(java.security.cert.CertificateFactorySpi,java.security.Provider,java.lang.String)
WARNING: Illegal reflective access by org.jruby.ext.openssl.SecurityHelper (file:/Users/headius/projects/jruby/lib/ruby/stdlib/jopenssl.jar) to constructor java.security.cert.CertificateFactory(java.security.cert.CertificateFactorySpi,java.security.Provider,java.lang.String)
More of these warnings will occur on Windows or when running without native IO, since in those cases we crack open core JDK IO classes.