RFR: JDK-8134157: adlc fails to compile with SS12u4

[David Holmes]

On 26/08/2015 10:45 PM, David Holmes wrote:
> On 26/08/2015 9:44 PM, Erik Joelsson wrote:
>> Further investigation revealed that this "error" was actually just a
>> warning being upgraded to error by -errwarn. The warning is only
>> activated by +w, which is turned on for adlc but not for the rest of the
>> hotspot build. Based on this, I have revised my proposal to just
>> disabling this warning for adlc and the particular compiler version.
>>
>> Webrev: http://cr.openjdk.java.net/~erikj/8134157/webrev.01/
>
> Sorry but as per bug report I still object to simply hiding this problem
> when we don't understand it. The code did not change and the compiler
> option did not change, but the new compiler gives this strange warning
> the implications of which are unclear.

Based on Kim's updates in the bug report I am now more comfortable with 
disabling the warning. I agree with Kim's comment that we should disable 
for >= SS12u4.

Thanks,
David

> David
> -----
>
>> /Erik
>>
>> On 2015-08-26 05:21, David Holmes wrote:
>>> On 26/08/2015 4:13 AM, Kim Barrett wrote:
>>>> On Aug 25, 2015, at 10:27 AM, Erik Joelsson
>>>> <erik.joelsson at oracle.com> wrote:
>>>>>
>>>>> Hello,
>>>>>
>>>>> We are working towards upgrading the officially supported compilers
>>>>> for JDK 9 and on Solaris, the proposed new compiler is Solaris
>>>>> Studio 12 update 4. When attempting to build with that compiler, the
>>>>> hotspot build fails very early with:
>>>>>
>>>>> "/opt/jprt/jprtadm/erik/jdk9-dev/hotspot/src/share/vm/adlc/adlparse.cpp",
>>>>>
>>>>> line 2331: Error: Could not find source for
>>>>> RegisterForm::addRegClass<RegClass>(const char*).
>>>>>
>>>>> This can be worked around by adding -template=extdef to the compiler
>>>>> flags. I propose we add this just when compiling adlc and for this
>>>>> particular version of Solaris Studio. See bug for further discussion
>>>>> of the issue.
>>>>>
>>>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8134157
>>>>> Webrev: http://cr.openjdk.java.net/~erikj/8134157/webrev/
>>>>>
>>>>> /Erik
>>>>
>>>> I don’t think we should make this change.
>>>
>>> Agreed. The need for the change makes no sense as nothing has changed:
>>> the code hasn't changed and the use of this flag has not changed.
>>> Hence this seems to be a compiler issue.
>>>
>>> David
>>> ----
>>>
>>>> I think a better alternative than mixing different -template options
>>>> would be to change adlc to use the “include model” for template
>>>> usage, as discussed in comments in the bug report.
>>>>
>>>> Also as discussed in the bug report, I don’t think we fully
>>>> understand the problem, since there appears to be other code in
>>>> hotspot that looks very similar and seemingly ought to run into the
>>>> same problem.  If only changing adlc as described doesn’t trip over
>>>> the same problem with that other code, then I don’t think we actually
>>>> understand the problem yet, and can’t evaluate proposed solutions.
>>>>
>>