RFR: 8352064: AIX: now also able to build static-jdk image with a statically linked launcher [v3]

[Magnus Ihse Bursie]

On Thu, 20 Mar 2025 14:30:58 GMT, Joachim Kern <jkern at openjdk.org> wrote:

>> After "JDK-8339480: Build static-jdk image with a statically linked launcher" AIX was not able to build the new target. Therefore with "JDK-8345590 AIX 'make all' fails after JDK-8339480" the new target was disabled again.
>> 
>> Now with this change we can enable the statically linked launcher target again.
>> There are 3 things to do.
>> 1.	Modify `dladdr()`. Because this API does not exist on AIX it is implemented based on the `loadquery()` API. Unfortunately, this API does only return the name of the executable, but not its path. Beforehand this was no problem, because we asked for a loaded library, for which the API provides the path. But now we are asking for the executable itself.
>> 2.	`dladdr()` is differently implemented three times in the openjdk code. In the static case I supressed now the usage of the additional modules containing version two and three. I know this shouldn't be the final version. Magnus mentioned that they have discussed from time to time to have a "basic JDK utility lib" that can be shared between hotspot and the JDK libraries. I think this is a good idea for the future, but far beyond the scope of this PR. The second best thing Magnus proposed is to only have the `dladdr()` functionality in Hotspot and then export it. Let's see how the community decides.
>> 3.	Because we lack a linker flag like `whole-archive`, I had to force the export of all symbols by creating export files containing all symbols of the static libs. I introduced the new rule for the export file generation as "raw" make recipes. Magnus claimed to use the `SetupExecute`. Unfortunately I was not able to make it function. So I still have my "raw" solution in place, but my last try with `SetupExecute` as comment beneath. Help is welcome.
>
> Joachim Kern has updated the pull request incrementally with one additional commit since the last revision:
> 
>   added needed include

Regaring point 2: the current solution works, and is acceptable, I think. The two excluded files only contain the dladdr() implementation, and this is implemented in hotspot, so no functionality is lost. Compacting this into just a single implementation is a separate issue, and need not be resolved now.

Regarding the name of `_generate_export_list_libjli.a_exec`: this is generated from the name of the SetupExecute rule, `generate_export_list_$(lib)`. I don't mind the name, it is clear. I don't see any particular point in keeping the name short, but if it bothers you, shorten the name of the rule. Try keeping it clear what it does, though.

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PR Comment: https://git.openjdk.org/jdk/pull/24062#issuecomment-2742949097