RFR: 8348862: runtime/ErrorHandling/CreateCoredumpOnCrash fails on Windows aarch64 [v3]

[David Holmes]

On Mon, 8 Sep 2025 19:26:58 GMT, Saint Wesonga <duke at openjdk.org> wrote:

>> The Windows AArch64 OpenJDK build uses vectored exception handling. The implementation registers a custom vectored exception handler, which calls the exception filter function that is shared with the x64 platform. However, this call only happens when using -xcomp. This has the side effect of not running the JVM error handling code that would create a core dump if only the interpreter is used. This change fixes this issue by unconditionally using the same exception handler as Windows x64. The CreateCoredumpOnCrash test now passes with this change.
>> 
>> Although vectored exception handling is used on Windows AArch64, the implementation currently uses the same safefetch implementation as x64, which relies on structured exception handling. This change fixes safefetch on Windows AArch64 to not use the SEH implemenation (in safefetch_windows.hpp). This change defines the static assembly language for the fetching code like the other aarch64 platforms have done and updates the exception handler to recognize exceptions from the safe fetch assembly instructions. This came up because the NMT gtests started failing after the change to the exception handler.
>> 
>> Exceptions with the DBG_PRINTEXCEPTION_C  exception code are also encountered in routine execution on Windows AArch64 so I excluded them from causing error reporting, similar to how EXCEPTION_BREAKPOINT is handled. I'm not sure if this handling needs to also be extended to exception codes with success codes in https://learn.microsoft.com/en-us/windows/win32/learnwin32/error-codes-in-com (based on the most significant bit of the 32-bit code)
>
> Saint Wesonga has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Move safefetch handling into existing _M_ARM64 block

Suggestions for os_windows.cpp: 
- Merge the AMD64 block at line 2658 with the one at 2651.
- Move line 2656 `Thread* t = ...` to line 2680 as `t` seems not used until line 2681

Thanks

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

PR Review: https://git.openjdk.org/jdk/pull/27074#pullrequestreview-3199611624