RFR: 8339112: Move JVM Klass flags out of AccessFlags [v3]

[Amit Kumar]

On Fri, 30 Aug 2024 20:11:06 GMT, Coleen Phillimore <coleenp at openjdk.org> wrote:

>> Coleen Phillimore has updated the pull request incrementally with three additional commits since the last revision:
>> 
>>  - Fix jvmci code.
>>  - Some C2 refactoring.
>>  - Assembly corrections from Matias and Dean.
>
> Thanks Chris and Matias for reviewing parts of this.

Hi @coleenp, 

I got this error while build on my Mac-M1, did you see something like this ? : 

ERROR: Failed to generate link optimization data. This is likely a problem with the newly built JVM/JDK.
#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/Users/amitkumar/jdk/src/hotspot/share/oops/klassFlags.hpp:72), pid=57968, tid=10499
#  assert(!is_value_based_class()) failed: set once
#
# JRE version:  (24.0) (fastdebug build )
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 24-internal-adhoc.amitkumar.jdk, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, bsd-aarch64)
# No core dump will be written. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /Users/amitkumar/jdk/make/hs_err_pid57968.log
#
#


These are the changes with which I am build the JVM. I can reproduce it on my s390x-machine as well. 

diff --git a/src/hotspot/share/runtime/globals.hpp b/src/hotspot/share/runtime/globals.hpp
index d442894798b..fbd1a2b3281 100644
--- a/src/hotspot/share/runtime/globals.hpp
+++ b/src/hotspot/share/runtime/globals.hpp
@@ -170,7 +170,7 @@ const int ObjectAlignmentInBytes = 8;
   product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL,                \
           "Force safe construction, as if all fields are final.")           \
                                                                             \
-  product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC,         \
+  product(bool, UnlockDiagnosticVMOptions, true, DIAGNOSTIC,         \
           "Enable normal processing of flags relating to field diagnostics")\
                                                                             \
   product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL,           \
@@ -819,7 +819,7 @@ const int ObjectAlignmentInBytes = 8;
   product(bool, RestrictContended, true,                                    \
           "Restrict @Contended to trusted classes")                         \
                                                                             \
-  product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC,              \
+  product(int, DiagnoseSyncOnValueBasedClasses, 1, DIAGNOSTIC,              \
              "Detect and take action upon identifying synchronization on "  \
              "value based classes. Modes: "                                 \
              "0: off; "                                                     \

-------------

PR Comment: https://git.openjdk.org/jdk/pull/20719#issuecomment-2324389377