On Thu, 30 May 2024 13:00:21 GMT, Magnus Ihse Bursie <i...@openjdk.org> wrote:
> This patch contains a set of changes to improve static builds. They will pave > the way for implementing a full static-only java launcher. The changes here > will: > > 1) Make sure non-exported symbols are made local in the static libraries. > This means that the risk of symbol conflict is the same for static libraries > as for dynamic libraries (i.e. in practice zero, as long as a consistent > naming scheme is used for exported functions). > > 2) Remove the work-arounds to exclude duplicated symbols. > > 3) Fix some code in hotspot and the JDK libraries that did not work properly > with a static java launcher. > > The latter fixes are copied from or inspired by the work done by @jianglizhou > and her team as part of the Project Leyden [Hermetic > Java](https://github.com/openjdk/leyden/tree/hermetic-java-runtime). Some open questions: * Do `os::lookup_function` need to be implemented on Windows too, for symmetry, even if it is only used on Unix platforms? * Many of the changes in Hotspot boils down to `os::dll_load` doing the wrong thing when running with a static build. Perhaps we should provide a better function that knows how to find and load a symbol for both static and dynamic builds, and use that instead of making a lot of tests for static/dynamic on each location we need to look up a symbol from some other JDK library. * I managed to replace most of the #ifdef STATIC_BUILD with runtime checks. There are some places remaining though. Apart from the #ifdefs needed for JNI/JVMTI, which will need spec changes to address, there are code in java_md_macosx.m, jio.c and awt_Mlib.c that I did not manage to turn into runtime checks. They will need some more thorough work than just changing an `#ifdef` to an `if () {`. * And of course, the code in the build system to share all .o files except the two linktype files is still under development... I moved this away from Draft state, since I think it needs some visibility, especially since it touches several different parts of the code base, and such reviews tend to take time. I think the code here is good and basically okay to integrate. This patch will not on it's own solve the entire problem of building a proper static launcher, but it takes several important steps along the way. I think the changes here are reasonable to integrate into mainline at this point. ------------- PR Comment: https://git.openjdk.org/jdk/pull/19478#issuecomment-2140743300 PR Comment: https://git.openjdk.org/jdk/pull/19478#issuecomment-2168635393
