Hermetic Java and static link

[Jiangli Zhou]

Thanks for the context.

The scope of hermetic Java involves statically linking the JDK/VM
native libraries. The requirements for statically linking with the
other dependency libraries can vary for different applications. As
part of the hermetic Java work, we have also experimented with
statically linking the JDK bundled native dependency libraries, such
as zlib, harfbuzz, etc. Statically linking with libc seems to be
challenging, based on the information that I know. According to
https://stackoverflow.com/questions/2725255/create-statically-linked-binary-that-uses-getaddrinfo,
musl supports static linking well.

Thanks,
Jiangli

On Wed, Oct 15, 2025 at 9:48 AM <ioi.lam at oracle.com> wrote:
>
> Hi Jiangli,
>
> We were trying to run the JVM on a "scratch" container image ( https://hub.docker.com/_/scratch )  but were running into problems with missing shared libraries.
>
> At first we tried to build the JVM into a static executable, but that turns out to be more complicated that we thought.
>
> We ended up simply copying the shared libraries from the build host into the docker image and that seemed to work for our use case.
>
> If I understand the question correctly, -static-libgcc is the default
> when building JDK on Linux.
>
>
>
> -static-libgcc affects only libgcc.a. To link all the other libraries (such as libc) statically, "g++ -static" need to be used.
>
>
> Thanks
>
> - Ioi
>
>
>
> CC'ing leyden-dev at openjdk.org
>
> Hi Ioi,
>
> For the current state of  JDK static linking support, the
> https://github.com/openjdk/leyden/tree/hermetic-java-runtime is about
> the same as the JDK mainline. Most of the JDK libraries and libjvm are
> statically linked with the launcher. Please see additional comments
> below.
>
> On Tue, Oct 14, 2025 at 10:04 AM <ioi.lam at oracle.com> wrote:
> >
> > Hi Jiangli,
> >
> > I tried building with
> > https://github.com/openjdk/leyden/tree/hermetic-java-runtime to see if I
> > can get a completely statically linked JVM, but the JVM is still
> > dynamically linked to a few shared libraries.
>
> Could you please elaborate on the specific libraries that you are
> looking into static linking as well? Such as libm, libasound, X11, ,
> etc? What are the specific benefits for statically linking with those?
>
> Do you have some context or details on what you are looking for?
>
> >
> > Is it possible to do a static link (with "gcc-static ...")?
>
> If I understand the question correctly, -static-libgcc is the default
> when building JDK on Linux. See
> https://github.com/openjdk/jdk/blob/3d95c83b14cf9a6f683776053e57c07b1847cc17/make/autoconf/lib-std.m4#L50.
> It's the case with linking the libjvm.so as well. E.g.:
>
>   g++ ... -static-libgcc -shared ... -Wl,-soname=libjvm.so -o
> support/modules_libs/java.base/server/libjvm.so ... -lm -ldl -lpthread
> -lrt -static-libstdc++
>
>
> Thanks,
> Jiangli
>
> >
> > Thanks
> >
> > - Ioi
> >
> > $ bash configure
> > $ cd build/linux-x64
> > $ make static-jdk-bundles
> > $ ls -l build/linux-x64/images/static-jdk/bin/java
> > -rwxr-xr-x. 1 opc opc 34915696 Oct 14 08:55
> > build/linux-x64/images/static-jdk/bin/java
> > $ ldd images/static-jdk/bin/java
> >      linux-vdso.so.1 (0x000075aad82ca000)
> >      libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x000075aad64c3000)
> >      libXext.so.6 => /lib/x86_64-linux-gnu/libXext.so.6 (0x000075aad829e000)
> >      libXi.so.6 => /lib/x86_64-linux-gnu/libXi.so.6 (0x000075aad828b000)
> >      libXrender.so.1 => /lib/x86_64-linux-gnu/libXrender.so.1
> > (0x000075aad827f000)
> >      libXtst.so.6 => /lib/x86_64-linux-gnu/libXtst.so.6 (0x000075aad8277000)
> >      libasound.so.2 => /lib/x86_64-linux-gnu/libasound.so.2
> > (0x000075aad63b9000)
> >      libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x000075aad8270000)
> >      libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6
> > (0x000075aad62ed000)
> >      libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0
> > (0x000075aad826b000)
> >      librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x000075aad8266000)
> >      libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x000075aad824a000)
> >      libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x000075aad6204000)
> >      libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x000075aad5e00000)
> >      /lib64/ld-linux-x86-64.so.2 (0x000075aad82cc000)
> >      libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x000075aad61db000)
> >      libbz2.so.1.0 => /lib/x86_64-linux-gnu/libbz2.so.1.0
> > (0x000075aad8234000)
> >      libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16
> > (0x000075aad61a3000)
> >      libbrotlidec.so.1 => /lib/x86_64-linux-gnu/libbrotlidec.so.1
> > (0x000075aad6195000)
> >      libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x000075aad822c000)
> >      libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6
> > (0x000075aad618d000)
> >      libbrotlicommon.so.1 => /lib/x86_64-linux-gnu/libbrotlicommon.so.1
> > (0x000075aad616a000)
> >      libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x000075aad6154000)
> >      libmd.so.0 => /lib/x86_64-linux-gnu/libmd.so.0 (0x000075aad6145000)
> >
>
>