RFR: 8357579: Compilation error: first argument in call to 'memset' is a pointer to non-trivially copyable type [v7]

[Jan Kratochvil]

On Fri, 7 Nov 2025 15:58:56 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> This STATIC_ASSERT does work for the trailing padding but not for potential padding introduced inside the struct. That sizeof(x)==number of mine is also not foolproof, but IMHO it is slightly safer.
>
> I don't think either approach can detect internal padding. E.g., I changed this:
> 
> 
> # ifdef _LP64
> - u2 _padding1;
> + u1 _padding1;
>   u4 _padding2;
> 
> 
> Neither static assert failed.
> 
> But if I changed this:
> 
> 
> # ifdef _LP64
>   u2 _padding1;
> - u4 _padding2;
> + u2 _padding2;
> 
> 
> My assert fails but yours doesn't. So hard coding a number cannot detect trailing paddings.

True. So I have added both. That sizeof check is for the case of:

   } _entry_specific;
 
+  void *_new_pointer;
   u2 _cpool_index;                   // Constant pool index

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PR Review Comment: https://git.openjdk.org/jdk/pull/26098#discussion_r2504453294