On Tue, 10 Sep 2024 13:51:55 GMT, Josef Eisl <[email protected]> wrote:
>> Magnus Ihse Bursie has updated the pull request incrementally with one
>> additional commit since the last revision:
>>
>> Also update build to link properly
>
> src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c line 135:
>
>> 133: #endif
>> 134:
>> 135: if (!JVM_IsStaticallyLinked()) {
>
> These "cross-library" link-type probes are a challenge for GraalVM native
> image. In native image, we statically link most standard JNI libraries into
> the final executable. However in some cases, for example AWT, static linking
> is not feasible due to their dependencies. Thus, we resort to dynamic
> linking. Have a mix of static and dynamic linking means that
> `JVM_IsStaticallyLinked` should give different answers based on the caller.
> Example:
> lets assume a follow-up change introduces a call to `JVM_IsStaticallyLinked`
> in libnet (which native image statically links):
> * if `JVM_IsStaticallyLinked` is called from libawt.so, we want to answer
> `false`
> * if `JVM_IsStaticallyLinked` is called from libnet.a, we want to answer
> `true`
>
> Is the mixed linking use case is something that the Hermetic Java effort is
> having on its radar?
>
> For this particular case, one solutions could be to avoid cross-library
> calls. I.e., instead of calling `JVM_IsStaticallyLinked`, have an
> `AWT_IsStaticallyLinked` that is local to the libawt. This is similar to the
> pattern also used for JLI.
Mixing static and dynamic libraries willy-nilly sounds like a situation that is
hard to resolve in a safe and sound way. The basic assumption here has been
that you either have all libraries dynamic, or all libraries static.
In the particular case you mention about libawt, I think the proper solution is
to sort out the mess that is libawt_headless/libawt_xawt. It seems to me that
the X support should be loaded using dlopen, not by hard dependencies to the X
libraries. I think that should solve your problem (as well as many other
problems).
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PR Review Comment: https://git.openjdk.org/jdk/pull/20666#discussion_r1752767100
