RFR: 8371893: [macOS aarch64] use dead_strip linker option to reduce binary size [v3]

[Matthias Baesken]

On Thu, 20 Nov 2025 16:00:30 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> The dead_strip linker option on macOS removes functions and data that are unreachable by the entry point or exported symbols.
>> Setting it can reduce the size of some binaries we generate quite a lot, for example (product build, Xcode 15 is used) :
>> (before -> after setting the option)
>> 
>> 1.4M -> 1.1M images/jdk/lib/libfontmanager.dylib
>> 264K -> 248K images/jdk/lib/libjavajpeg.dylib
>> 152K -> 132K images/jdk/lib/libjli.dylib
>> 388K -> 296K images/jdk/lib/liblcms.dylib
>> 164K -> 128K images/jdk/lib/libzip.dylib
>> 
>> 
>> and libjvm :
>> 
>> 20M -> 18M images/jdk/lib/server/libjvm.dylib
>> 146M -> 137M images/jdk/lib/server/libjvm.dylib.dSYM
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix Windows issues

For the Apple linker there seem to be also a way to mark some sections with `S_ATTR_NO_DEAD_STRIP` to avoid the dead strip operation
https://maskray.me/blog/2021-02-28-linker-garbage-collection
'Sections with the S_ATTR_NO_DEAD_STRIP flag'
But I am not sure how to do this in the HS code directly.

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PR Comment: https://git.openjdk.org/jdk/pull/28319#issuecomment-3559017189