RFR: 8351194: Clean up Hotspot SA after 32-bit x86 removal [v7]

[David Holmes]

On Wed, 29 Oct 2025 14:13:48 GMT, Kerem Kat <krk at openjdk.org> wrote:

>> Remove 32-bit x86 specific code from the HotSpot Serviceability Agent following the removal of 32-bit x86 support.
>> 
>> - Removed x86-specific implementations and ifdef blocks.
>> - Renamed files with X86 in the name when they are also used from AMD64, e.g. `X86Frame` → `AMD64Frame`.
>> - Cleaned up platform detection logic in `PlatformInfo`.
>> - Updated documentation references.
>
> Kerem Kat has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Update src/jdk.hotspot.agent/doc/hsdb.html
>   
>   Co-authored-by: Chris Plummer <chris.plummer at oracle.com>

Looks good! Two minor additional changes requested, but hitting approve.

Thanks

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebugger.java line 55:

> 53:   // The returned array of register contents is guaranteed to be in
> 54:   // the same order as in the DbxDebugger for Solaris/amd64; that is,
> 55:   // the indices match those in debugger/amd64/AMD64ThreadContext.java.

I would just delete this comment block as we no longer support Solaris and the reference to dbx is obsolete and we have no idea if we are maintaining order with any other debuggers.

src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/VM.java line 884:

> 882:       includes but is not spanned by the interpreter and code cache.
> 883:       Only used in the debugging system, for implementing
> 884:       JavaThread.currentFrameGuess() on amd64. */

Delete the last sentence - it is used by currentFrameGuess on multiple platforms now.

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Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27844#pullrequestreview-3397366920
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2476353726
PR Review Comment: https://git.openjdk.org/jdk/pull/27844#discussion_r2476356683