RFR: 8272113: Build compare script fails with differences in classlist

[Ioi Lam]

On Mon, 9 Aug 2021 08:14:44 GMT, Thomas Schatzl <tschatzl at openjdk.org> wrote:

>> The CDS classlist is generated with the `-XX:DumpLoadedClassList` option, which writes the name of the classes as they are being loaded. Since class loading order is affected by thread switching, the classes may appear in a non-deterministic order.
>> 
>> Previously, the build compare script would sort the classlist before comparing. Since https://bugs.openjdk.java.net/browse/JDK-8272113, each class in the classlist has a new ID, so even after sorting, the contents would differ:
>> 
>> 
>> $ diff classlist.1 classlist.2
>> 207,208c207,208
>> < jdk/internal/misc/VM id: 201
>> < jdk/internal/util/SystemProps id: 202
>> ---
>>> jdk/internal/misc/VM id: 202
>>> jdk/internal/util/SystemProps id: 201
>> 
>> 
>> The fix is to strip the id before doing the file comparison.
>> 
>> Tested with:
>> 
>> `mach5 remote-build -b linux-aarch64-cmp-baseline,macosx-x64-cmp-baseline,linux-x64-cmp-baseline,linux-arm32-open-cmp-baseline,windows-x64-cmp-baseline`
>
> Lgtm.

Thanks @tschatzl and @hseigel for the review.

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PR: https://git.openjdk.java.net/jdk/pull/5041