RFR: 8329982: compiler/jvmci/jdk.vm.ci.code.test/src/jdk/vm/ci/code/test/SimpleDebugInfoTest.java failed assert(oopDesc::is_oop_or_null(val)) failed: bad oop found

[Tom Rodriguez]

On Wed, 1 May 2024 15:03:08 GMT, Doug Simon <dnsimon at openjdk.org> wrote:

> This PR adds the missing nmethod entry barriers to JVMCI hand assembled tests.
> It also closes the escape hatch in jvmciCodeInstaller.cpp that allowed JVMCI code to be installed without nmethod entry barriers.

In the long term I'm not sure it's worth trying to maintain these assembler tests.  The barrier verification code is very weak and on aarch64 it's slightly complicated so we're barely checking that it really matches.  I guess this is good enough until we get further problems.

I think you can simplify some other logic that deals with the optionality of the barrier.  Start with removing JVMCINMethodData::has_entry_barrier and maybe update some of the comments to reflect that it's always emitted.  And places that check _nmethod_entry_patch_offset for -1 can be removed or weakened.

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PR Comment: https://git.openjdk.org/jdk/pull/19035#issuecomment-2088836198