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

[Erik Joelsson]

Hello Vladimir,

The new organization of the checks looks good. Just found one minor nit, 
in lib-elf.m4, no need to AC_SUBST(ENABLE_AOT) again.

/Erik


On 2016-10-29 04:23, Vladimir Kozlov wrote:
> Updated build webrevs (webrev.2)
>
> http://cr.openjdk.java.net/~kvn/aot/top.webrev.2/
> http://cr.openjdk.java.net/~kvn/aot/hs.make.webrev.2/
>
> Use one ENABLE_AOT variable in all config and make files (removed 
> NEEDS_LIB_JELFSHIM).
>
> Moved HOTSPOT_SETUP_JVM_FEATURES after LIB_SETUP_LIBRARIES.
>
> First, check for linux-x64 presence of jdk.aot and jdk.vm.compiler 
> directories. Set ENABLE_AOT=true if all are present. Throw config 
> errors if --enable-aot is specified but sources are missing or on 
> different platforms.
>
> Second, in lib-elf.m4, when ENABLE_AOT==true check if libelf.h is 
> present and usable.
> Throw config errors if --enable-aot is specified but libelf.h is missing.
> Otherwise warnings and set ENABLE_AOT==false.
>
> Third, check ENABLE_AOT in HOTSPOT_SETUP_JVM_FEATURES to set 
> JVM_FEATURES.
>
> Thanks,
> Vladimir
>
> On 10/28/16 3:27 AM, Erik Joelsson wrote:
>>
>>
>> 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