RFR: 8283689: Update the foreign linker VM implementation [v17]

[Vladimir Ivanov]

On Thu, 12 May 2022 16:58:36 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

>> Hi,
>> 
>> This PR updates the VM implementation of the foreign linker, by bringing over commits from the panama-foreign repo.
>> 
>> This is split off from the main JEP integration for 19, since we have limited resources to handle this. As such, this PR might fall over to 20, but it would be nice if we could get it into 19.
>> 
>> I've written up an overview of the Linker architecture here: http://cr.openjdk.java.net/~jvernee/docs/FL_Overview.html it might be useful to read that first.
>> 
>> This patch moves from the "legacy" implementation, to what is currently implemented in the panama-foreign repo, except for replacing the use of method handle combinators with ASM. That will come in a later path. To recap. This PR contains the following changes:
>> 
>> 1. VM stubs for downcalls are now generated up front, instead of lazily by C2 [1].
>> 2. the VM support for upcalls/downcalls now support all possible call shapes. And VM stubs and Java code implementing the buffered invocation strategy has been removed  [2], [3], [4], [5].
>> 3. The existing C2 intrinsification support for the `linkToNative` method handle linker was no longer needed and has been removed [6] (support might be re-added in another form later).
>> 4. Some other cleanups, such as: OptimizedEntryBlob (for upcalls) now implements RuntimeBlob directly. Binding to java classes has been rewritten to use javaClasses.h/cpp (this wasn't previously possible due to these java classes being in an incubator module) [7], [8], [9].
>> 
>> While the patch mostly consists of VM changes, there are also some Java changes to support (2).
>> 
>> The original commit structure has been mostly retained, so it might be useful to look at a specific commit, or the corresponding patch in the [panama-foreign](https://github.com/openjdk/panama-foreign/pulls?q=is%3Apr) repo as well. I've also left some inline comments to explain some of the changes, which will hopefully make reviewing easier.
>> 
>> Testing: Tier1-4
>> 
>> Thanks,
>> Jorn
>> 
>> [1]: https://github.com/openjdk/jdk/pull/7959/commits/048b88156814579dca1f70742061ad24942fd358
>> [2]: https://github.com/openjdk/jdk/pull/7959/commits/2fbbef472b4c2b4fee5ede2f18cd81ab61e88f49
>> [3]: https://github.com/openjdk/jdk/pull/7959/commits/8a957a4ed9cc8d1f708ea8777212eb51ab403dc3
>> [4]: https://github.com/openjdk/jdk/pull/7959/commits/35ba1d964f1de4a77345dc58debe0565db4b0ff3
>> [5]: https://github.com/openjdk/jdk/pull/7959/commits/4e72aae22920300c5ffa16fed805b62ed9092120
>> [6]: https://github.com/openjdk/jdk/pull/7959/commits/08e22e1b468c5c8f0cfd7135c72849944068aa7a
>> [7]: https://github.com/openjdk/jdk/pull/7959/commits/451cd9edf54016c182dab21a8b26bd8b609fc062
>> [8]: https://github.com/openjdk/jdk/pull/7959/commits/4c851d2795afafec3a3ab17f4142ee098692068f
>> [9]: https://github.com/openjdk/jdk/pull/7959/commits/d025377799424f31512dca2ffe95491cd5ae22f9
>
> Jorn Vernee has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 98 commits:
> 
>  - Merge branch 'master' into JEP-19-VM-IMPL2
>  - Undo spurious changes.
>  - Merge branch 'JEP-19-VM-IMPL2' of https://github.com/JornVernee/jdk into JEP-19-VM-IMPL2
>  - Apply copyright year updates per request of @nick-arm
>    
>    Co-authored-by: Nick Gasson <nick.gasson at arm.com>
>  - Fix overwritten copyright years.
>  - Missed 2 years
>  - Update Oracle copyright years
>  - Revert "Block async exceptions during upcalls"
>    
>    This reverts commit b29ad8f46732666f2d07e63ce8701b1eb7bed790.
>  - Block async exceptions during upcalls
>  - Merge branch 'foreign-preview-m' into JEP-19-VM-IMPL2
>  - ... and 88 more: https://git.openjdk.java.net/jdk/compare/2c5d1362...f55b6c59

Looks good.

src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp line 5531:

> 5529: }
> 5530: 
> 5531: // On64 bit we will store integer like items to the stack as

Missing space.

src/hotspot/cpu/x86/macroAssembler_x86.cpp line 933:

> 931:     } else {
> 932:       assert(dst.is_single_reg(), "not a stack pair: (%s, %s), (%s, %s)",
> 933:         src.first()->name(), src.second()->name(), dst.first()->name(), dst.second()->name());

Still not indented properly.

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Marked as reviewed by vlivanov (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7959