RFR: 8017234: Hotspot should stop using mapfiles [v2]

[Magnus Ihse Bursie]

On Thu, 22 Feb 2024 11:16:37 GMT, Kevin Walls <kevinw at openjdk.org> wrote:

>>> But for platform consistency, it might make sense to export these even on gcc as well.
>> 
>> JDK-8288293 would definitely like that a lot
>
> Thanks - when I last tried, e.g. "call universe()" would work on Linux/gdb, so I think gdb did resolve a local symbol (which cannot be found by callling dlsym, but can be found in the binary symboltable).
> On Windows the debug.cpp symbols just weren't in the binary at all, then with JDK-8264593 JNIEXPORT they were, and appeared in the .map file we generate also.
> 
> So I am saying I added the JNIEXPORT for Windows, to get the debug.cpp symbols into the binary.
> This removes JNIEXPORT for gcc, which already had the debug.cpp symbols in the binary.
> 
> But I will go check this...

> they were absent from .dynsym but available in .symtab as bind: local, visibility: default. Now they are completely gone.

I don't think that statement is correct. Or else my understanding about symbol tables is incomplete. Both `nm` (which shows `.symtab`) and `nm -D` (which shows `.dynsym`) are identical for the libjvm.so before and after the patch wrt to the JNIEXPORTed debug.cpp functions.

Was this a statement of your understanding of the situation, or could you spot an actual difference? If it is the latter, please let me know how I can view this difference.

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PR Review Comment: https://git.openjdk.org/jdk/pull/17955#discussion_r1499163789