Compilation failure with clang 20

[Pedro Lamarão]

Hello all,

Thanks for your hard work on this project!

I am posting here because the issue tracker in Github is disabled and I am
unsure where else to post such issues.

I am seeing a compilation failure with current HEAD and clang 20, three
instances of the same complaint:

* For target hotspot_variant-server_libjvm_objs_resolvedMethodEntry.o:
/home/centos/valhalla/src/hotspot/share/oops/resolvedMethodEntry.cpp:43:12:
error: first argument in call to 'memset' is a pointer to non-trivially
copyable type 'ResolvedMethodEntry' [-Werror,-Wnontrivial-memcall]
   43 |     memset(this, 0, sizeof(*this));
      |            ^
/home/centos/valhalla/src/hotspot/share/oops/resolvedMethodEntry.cpp:43:12:
note: explicitly cast the pointer to silence this warning
   43 |     memset(this, 0, sizeof(*this));
      |            ^
      |            (void*)

Taking a quick look at the declaration for ResolvedMethodEntry, it seems to
me that it could be made trivially copyable by defining copy
constructor and copy assignment = default. I suppose the compiler considers
this in principle to invoke undefined behaviour.

git HEAD:

commit cab7c4bdbf91a58c22b2d42f7ccd805238c349e4

BuIld configuration:

Configuration summary:
* Name:           linux-x86_64-server-release
* Debug level:    release
* HS debug level: product
* JVM variants:   server
* JVM features:   server: 'cds compiler1 compiler2 epsilongc g1gc jfr
jni-check jvmci jvmti management parallelgc serialgc services shenandoahgc
vm-structs zgc'
* OpenJDK target: OS: linux, CPU architecture: x86, address length: 64
* Version string: 25-internal-adhoc.centos.valhalla (25-internal)
* Source date:    1740061836 (2025-02-20T14:30:36Z)

Tools summary:
* Boot JDK:       openjdk version "24" 2025-03-18 OpenJDK Runtime
Environment (build 24+36-3646) OpenJDK 64-Bit Server VM (build 24+36-3646,
mixed mode, sharing) (at /home/centos/jdk-24)
* Toolchain:      clang (clang/LLVM)
* C Compiler:     Version 20.1.2 (at /usr/bin/clang)
* C++ Compiler:   Version 20.1.2 (at /usr/bin/clang++)

Build performance summary:
* Build jobs:     15
* Memory limit:   15861 MB

-- 
Pedro Lamarão
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