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

[Chris Plummer]

On Wed, 19 Nov 2025 15:20:31 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> There seem to be attributes for this kind of use case in clang, e.g. retain
> https://reviews.llvm.org/D97447
> https://clang.llvm.org/docs/AttributeReference.html#retain
> Should we add this to 'class Metadata' ?
> If we can do it with attributes or something similar (and without changing lots of code locations) it sounds better to me than adjusting the coding.
> 'Pseudo dead' stuff that is used from external tools (so it is not really 'dead' in practise) should be somehow marked to assist the tools.
> There is also an attribute 'used' that looks similar.

I tried the following but it didn't work. Perhaps I don't have the syntax right:


--- a/src/hotspot/share/oops/metadata.hpp
+++ b/src/hotspot/share/oops/metadata.hpp
@@ -30,6 +30,7 @@
 #include "utilities/ostream.hpp"
 
 // This is the base class for an internal Class related metadata
+#pragma retain Metadata
 class Metadata : public MetaspaceObj {
   // Debugging hook to check that the metadata has not been deleted.
   NOT_PRODUCT(int _valid;)


Note `retain` and `used` are listed under function attributes. They probably don't apply to data.

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PR Comment: https://git.openjdk.org/jdk/pull/28319#issuecomment-3553656342