RFR: 8344904: Interned strings in old classes are not stored in CDS archive [v2]

[Calvin Cheung]

On Tue, 26 Nov 2024 05:32:44 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> Before this fix, CDS will only archive interned strings that are reachable from `ConstantPool::resolved_references()`, which is created only after a class is linked. However, old classes are not linked, so we didn't archive their interned strings.
>> 
>> It's possible for the Java mirror of an (unlinked) old class to point to interned strings. E.g.,
>> 
>> 
>> public super class OldClassWithStaticString
>>     version 49:0
>> {
>>     public static final Field s:"Ljava/lang/String;" = String "xxxx123yyyy456";
>> 
>> 
>> The 's' field is initialized during class file parsing, so we must intern the `"xxxx123yyyy456"` string.
>> 
>> The fix is to collect interned strings from the static fields of unlinked classes.
>
> Ioi Lam has updated the pull request incrementally with one additional commit since the last revision:
> 
>   @dholmes-ora comments

LGTM

-------------

Marked as reviewed by ccheung (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/22340#pullrequestreview-2473721717