RFR: 8017234: Hotspot should stop using mapfiles

[Julian Waters]

On Thu, 22 Feb 2024 09:49:41 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

>> No, it doesn't. Even after [JDK-8264593](https://bugs.openjdk.org/browse/JDK-8264593) the symbols from debug.cpp were not exported on Linux, since they were not mentioned in `make/data/hotspot-symbols`, and thus were made local.
>> 
>> The reason I put this in was to keep parity with the symbol table before and after the patch.
>> 
>> My guess is that it was only on Windows it was necessary that the functions where JNIEXPORTed, otherwise someone would have complained after JDK-8264593. But for platform consistency, it might make sense to export these even on gcc as well. After this PR is integrated, this is easy to do -- just remove the above hack.
>
> they were absent from .dynsym but available in .symtab as bind: local, visibility: default. Now they are completely gone.
> 
> The symbols were supposed to be used from gdb. I'm not sure if gdb can access local symbols, so it's possible that they didn't work even before this change.

> But for platform consistency, it might make sense to export these even on gcc as well.

JDK-8288293 would definitely like that a lot

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PR Review Comment: https://git.openjdk.org/jdk/pull/17955#discussion_r1498978685