RFR: JDK-8320005 : Native library suffix impact on hotspot code in AIX [v2]

[suchismith1993]

On Wed, 22 Nov 2023 16:24:24 GMT, suchismith1993 <duke at openjdk.org> wrote:

>> J2SE agent does not start and throws error when it tries to find the shared library ibm_16_am.
>> After searching for ibm_16_am.so ,the jvm agent throws and error as dll_load fails.It fails to identify the shared library ibm_16_am.a shared archive file on AIX.
>> Hence we are providing a function which will additionally search for .a file on AIX ,when the search for .so file fails.
>
> suchismith1993 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   change macro position

> I'm not a big fan of this approach. We accumulate more and more "#ifdef AIX" in shared code because of many recent AIX additions. No other platform has such a large ifdef footprint in shared code.
> 
> I argue that all of this should be handled inside os_aix.cpp and not leak out into the external space:
> 
> If .a is a valid shared object format on AIX, this should be handled in `os::dll_load()`, and be done for all shared objects. If not, why do we try to load a static archive via dlload in this case but not in other cases?
> 
> _If_ this is needed in shared code, the string replacement function should be a generic utility function for all platforms, and it should be tested with a small gtest. A gtest would have likely uncovered the buffer overflow too.

So i tried to check how to move the code to os_aix file. 
A few problems is see : 
1. When i have to implemented the logic at dll_load function, i would have to repeat a lot of code after dlopen, i.e i have to call dlopen again for .so files and hence i have to copy the logic again for it. 
2. Currently using function before dll_load,in the shared code makes this a bit easier. 
I have an alternate suggestion . 
Shall we declare the utlity function as part of os ? and implement it platform wise. 
In that way we just keep the actual implentation and aix and in windows and linux we keep it empty. 
So that way we can just call the utility function in shared code and it wouldnt affect other platform and will run the usecase for AIX. 
If that is not acceptable, then is there a better way to avoid repeating the dlopen again in os_aix file ?

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

PR Comment: https://git.openjdk.org/jdk/pull/16604#issuecomment-1824737158