RFR: 8368050: Validation missing in ClassFile signature factories [v3]

[Chen Liang]

On Fri, 19 Sep 2025 07:03:56 GMT, Adam Sotona <asotona at openjdk.org> wrote:

>> Chen Liang has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Fix links
>
> src/java.base/share/classes/java/lang/classfile/Signature.java line 246:
> 
>> 244:          *
>> 245:          * @param outerType signature of the outer type, may be {@code null}
>> 246:          *        to indicate this is a top-level class or interface
> 
> Actually here is the ambiguity. Null outer type is more than frequently used also for inner classes.
> Signatures of inner classes are mainly encoded without the outer type and with the $-notation of the outer$inner as the class name.

Clarified by introducing examples of signature strings and on the className/outerType.

> src/java.base/share/classes/jdk/internal/classfile/impl/ClassRemapperImpl.java line 312:
> 
>> 310:                 Signature.ClassTypeSig.of(
>> 311:                         cts.outerType().map(this::mapSignature).orElse(null),
>> 312:                         Util.toInternalName(map(cts.classDesc())), // wrong, needs fix with InnerClasses
> 
> Signatures of inner classes should be disambiguated to avoid this kind of confusions.

I aim to preserve the existing behavior for now. We can create a dedicated RFE to disambiguate for both here and InnerClasses later.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27380#discussion_r2364767064
PR Review Comment: https://git.openjdk.org/jdk/pull/27380#discussion_r2364765011