RFR: JDK-8294902: Undefined Behavior in C2 regalloc with null references [v6]
Andrew Haley
aph at openjdk.org
Fri Dec 2 11:05:12 UTC 2022
On Fri, 2 Dec 2022 10:44:42 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:
>> Andrew Haley has updated the pull request incrementally with one additional commit since the last revision:
>>
>> Feedback from reviewers
>
> src/hotspot/share/opto/postaloc.cpp line 259:
>
>> 257: if (!can_change_regs) {
>> 258: return blk_adjust; // Only check stupid copies!
>> 259: }
>
> Style nit here and in other places: weren't these blocks separated by newline before?
I'm not sure what you mean. Can you make these Suggestions? Thanks.
> src/hotspot/share/utilities/globalDefinitions_gcc.hpp line 155:
>
>> 153: char* c = (char*)(void*)&dummyObj->field; \
>> 154: return (size_t)(c - space); \
>> 155: }()
>
> I am very surprised this does not produce any warnings! Let me test this on different GCCs...
Of course we can't exclude the possibility of warnings, given that taking the offset of a field of a non-POD class is unspecified behaviour. Having said that, I'm not sure exactly what it'd be warning about.
-------------
PR: https://git.openjdk.org/jdk/pull/10920
More information about the hotspot-dev
mailing list