RFR(XS): 8252051: Make mlvmJvmtiUtils strncpy uses GCC 10.x friendly

[Vladimir Kozlov]

+1

Vladimir K

On 8/19/20 3:25 PM, Igor Ignatyev wrote:
> LGTM
> -- Igor
> 
>> On Aug 19, 2020, at 3:14 PM, Mikael Vidstedt <mikael.vidstedt at oracle.com> wrote:
>>
>>
>> Please review this small change which updates the strncpy code in mlvmJvmtiUtils.cpp to make gcc 10.x happy:
>>
>> JBS: https://bugs.openjdk.java.net/browse/JDK-8252051
>> webrev: http://cr.openjdk.java.net/~mikael/webrevs/8252051/webrev.00/open/webrev/
>>
>> * Background (from JBS)
>>
>> gcc 10.2 is producing a warning for mlvmJmvtiUtils.cpp:
>>
>> In file included from test/hotspot/jtreg/vmTestbase/vm/mlvm/indy/func/jvmti/share/libIndyRedefineClass.cpp:31:
>> test/hotspot/jtreg/vmTestbase/vm/mlvm/share/mlvmJvmtiUtils.cpp:100:12: error: 'char* strncpy(char*, const char*, size_t)' specified bound 256 equals destination size [-Werror=stringop-truncation]
>>   100 | strncpy(mn->classSig, szSignature, sizeof(mn->classSig));
>>       | ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> cc1plus: all warnings being treated as errors
>>
>> It seems like gcc is not smart enough to realize that the strncpy on the previous line (mn->methodName) cannot modify szSignature.
>>
>>
>> * Testing
>>
>> tier1 and test/hotspot/jtreg:vmTestbase_vm_mlvm locally
>>
>>
>> Cheers,
>> Mikael
>>
>