RFR: 8370438: Offer link time optimization support on library level [v10]

[Matthias Baesken]

On Sat, 8 Nov 2025 00:34:02 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

>> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add lto to EXTRA_FLAGS, not to OPT
>
> make/modules/java.desktop/lib/ClientLibraries.gmk line 229:
> 
>> 227:       EXCLUDES := $(LIBSPLASHSCREEN_EXCLUDES), \
>> 228:       OPTIMIZATION := SIZE, \
>> 229:       LINK_TIME_OPTIMIZATION := true, \
> 
> You do not need to change it in this patch, it can be done separately per lib.

I think there was the concern raised previously, that without setting it for at least one lib, nobody would use/try it and the feature would 'rot' .

(there was also the idea to add a configure option to enable/disable the whole 'lto on jdk native libs' ; I can add this but currently not sure if this is desired)

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PR Review Comment: https://git.openjdk.org/jdk/pull/27976#discussion_r2509194261