[9] RFR(M) 8166416: [AOT] Integrate JDK build changes and launcher 'jaotc' for AOT compiler

[Erik Joelsson]

On 2016-10-28 11:09, Volker Simonis wrote:
> On Fri, Oct 28, 2016 at 10:57 AM, Erik Joelsson
> <erik.joelsson at oracle.com> wrote:
>> Hello,
>>
>>
>> On 2016-10-28 09:56, Vladimir Kozlov wrote:
>>> Webrevs updated in place (please, reload webpage to get new version).
>>> generated-configure.sh changes are included.
>>>
>>> http://cr.openjdk.java.net/~kvn/aot/top.webrev/
>>> http://cr.openjdk.java.net/~kvn/aot/jdk.webrev/
>>> http://cr.openjdk.java.net/~kvn/aot/hs.make.webrev/
>>>
>>> libelfshim generation is guarded by ENABLE_AOT as Volker suggested.
>>>
>>> I did not figure out how switch off ENABLE_AOT if libelf not found. So I
>>> changed warning to configuration error:
>>>
>>> error: libelf not found, cannot build AOT. Disable AOT build:
>>> --enable-aot=no. You might be able to fix this by running 'sudo yum install
>>> elfutils-libelf-devel'.
>>>
>>> Which is not correct since AOT build is enabled by default on linux-x64.
>>> Need help with this.
>>>
>> I think it should be fine moving HOTSPOT_SETUP_JVM_FEATURES to after
>> LIB_SETUP_LIBRARIES in configure.ac. (Note that many of these calls are just
>> ordered as they happened to be, though some really need to be before or
>> after others. I cannot find a reason for these two.) Then you can
>> enable/disable AOT after looking for libelf. It depends on what kind of
>> behavior you want.
>>
>> If libelf isn't commonly installed, then having configure use it, and enable
>> AOT if it is, and semi silently just disabling AOT if it's not is fine. We
>> can define our Oracle builds to explicitly set --enable-aot to get an early
>> fail on a missing dependency. That's inline with current configure behavior
>> so I like that.
> I'm fine with that. But then we shouldn't warn if we don't find
> libelf. We should only warn, if '--enable-aot' was explicitly
> requested by the user and if this request can't be fulfilled because
> of the missing libelf dependency.
--enable-aot and not finding libelf should result in an error. If on 
linux-x64 where aot is default enabled, there should be a warning that 
it was disabled because libelf is missing. This warning would now need 
to be in the ENABLE_AOT logic.

/Erik