RFR: 8336468: Reflection and MethodHandles should use more precise initializer checks [v2]

[Chen Liang]

On Tue, 16 Jul 2024 17:12:08 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> This PR should cover the Reflection/MethodHandles part of [JDK-8336103](https://bugs.openjdk.org/browse/JDK-8336103).
>>  
>> There are places where we change the behavior: `clinit` would now be recorded as "method", instead of "constructor". Tracing back the uses of `get_flags`: it is used for initializing `java.lang.ClassFrameInfo.flags`. There seem to be no readers for this field in VM. Java side for `j.l.CFI` does not seem to check any method/constructor flags. So I would say this change in behavior is not really visible, and there is no need to try and keep the old (odd) behavior.
>> 
>> I also inlined the `select_method` definition, which allows for a bit more straight-forward local code, and obviates the need for wrapping things with `methodHandle`.
>> 
>> @mlchung, you probably want to look at this more closely.
>> 
>> Additional testing:
>>  - [x] Linux x86_64 server fastdebug, `tier1`
>>  - [x] Linux x86_64 server fastdebug, `all`
>
> Aleksey Shipilev has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:
> 
>  - Merge branch 'master' into JDK-8336468-reflection-init-checks
>  - Remove unnecessary handle-izing
>  - Fix
>  - Fix

src/hotspot/share/runtime/reflection.cpp line 769:

> 767: 
> 768: oop Reflection::new_method(const methodHandle& method, bool for_constant_pool_access, TRAPS) {
> 769:   // Allow sun.reflect.ConstantPool to refer to <clinit> methods as java.lang.reflect.Methods.

Not quite related, but it's jdk.internal.reflect.ConstantPool now :)

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PR Review Comment: https://git.openjdk.org/jdk/pull/20192#discussion_r1680121069