RFR: JDK-8311076: RedefineClasses doesn't check for ConstantPool overflow

[Coleen Phillimore]

On Fri, 9 Feb 2024 02:34:26 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

>> The fix adds check that merged constant pool does not overflow u2 (two-byte unsigned).
>> The check is added after merging `the_class` and `scratch_class` constant pools, but before rewriting constant pool references.
>> 
>> testing:
>>  - sanity tier1;
>>  - all RedefineClasses/RetransformClasses tests:
>>    - test/jdk/java/lang/instrument
>>    - test/hotspot/jtreg/serviceability/jvmti/RedefineClasses
>>    - test/hotspot/jtreg/vmTestbase/nsk/jvmti/RedefineClasses
>>    - test/hotspot/jtreg/vmTestbase/nsk/jvmti/RetransformClasses
>
> src/hotspot/share/prims/jvmtiRedefineClasses.cpp line 1828:
> 
>> 1826:   // ensure merged constant pool size does not overflow u2
>> 1827:   if (merge_cp_length > 0xFFFF) {
>> 1828:     return JVMTI_ERROR_INTERNAL;
> 
> Doesn't it make a sense to add some logging there so user could easier understand the problem?

Seems like a good idea, you can use log_warning(redefine, class, constantpool)("...")

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PR Review Comment: https://git.openjdk.org/jdk/pull/17759#discussion_r1483825615