RFR: 8303796: Optionally build fully statically linked JDK image

[Jiangli Zhou]

On Sun, 30 Apr 2023 18:34:12 GMT, Alan Bateman <alanb at openjdk.org> wrote:

> > The build is already capable of producing .a files and this patch is building on top of that build feature. The current .a file creation is used by the downstream graal build which needs it for nativeimage.
> 
> Also builds on recent changes to remove duplicate symbol names. It's good that the PR demonstrates that these can be linked to create "javastatic" but having it copy into the run-time image created by jlink is probably not the eventual outcome.
> 
> A possible direction on this is for the build to create a set of packaged modules with the .a files, then have an alternative image builder in jlink that integrates with the native linker. Combined with other parts in Jiangli's slides/proposal, it would mean that jlink could produce a single executable that would work for both the JDK or any set of modules.

The comment from @AlanBateman helped me realize that I should be more specific (in my earlier comment regarding "withdraw the current PR first and extract the .a part into a new PR") about the needed fixes/enhancements related to .a part:

- Create libjvm.a as well when building static-libs-image target, include it in 'images/static-libs/lib'
- Filter out "external" .o files (those are the .o files included from different JDK libraries and needed when creating the .so shared library only) from .a libraries
- For libjvm.a specifically, exclude operator_new.o
- Handle long arguments case for static build in make/common/NativeCompilation.gmk
- Ensure zlib and freetype are bundled when building the static-libs-image target, i.e. libzlib.a and libfreetype.a are included in 'images/static-libs/lib'

It's probably best to create a separate enhancement/bug for those (will create shortly) and continue using JDK-8303796 for the broader discussion/effort.

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PR Comment: https://git.openjdk.org/jdk/pull/13709#issuecomment-1530368068