Problems with non Oracle boot JDKs and class file version 52

[Jonathan Gibbons]

On 12/07/2012 09:37 AM, Mandy Chung wrote:
> On 12/7/12 4:42 AM, Erik Joelsson wrote:
>> On 2012-12-07 13:06, David Holmes wrote:
>>>
>>> Here's the failing command (edited for presentation):
>>>
>>> /usr/lib/jvm/java-7-openjdk-amd64/bin/java -Xms64M -Xmx1100M
>>> -XX:PermSize=32m -XX:MaxPermSize=160m -XX:ThreadStackSize=1536 \
>>>
>>> -Xbootclasspath/a:/java/embedded/users/dh198349/build-infra/builds/b00/se-linux-i586-ea/jdk/classes 
>>>
>>>
>
> ^^^^ - this seems the cause of the problem?
>
> To run the bootstrap javac (v51), it can't set -Xbootclasspath to 
> jdk8/classes (v52).



Yes, why  is this line here at all?  Try deleting it.

-- Jon


>
> Mandy
>
>>>
>>> "-Xbootclasspath/p:/java/embedded/users/dh198349/build-infra/builds/b00/se-linux-i586-ea/langtools/dist/bootstrap/lib/javac.jar" 
>>>
>>> -jar
>>> /java/embedded/users/dh198349/build-infra/builds/b00/se-linux-i586-ea/langtools/dist/bootstrap/lib/javac.jar 
>>>
>>> \
>>>             -XDprocess.packages -proc:only \
>>>             -processor com.sun.tools.javac.sym.CreateSymbols \
>>>
>>> -Acom.sun.tools.javac.sym.Jar=/java/embedded/users/dh198349/build-infra/builds/b00/se-linux-i586-ea/images/lib/rt.jar 
>>>
>>> \
>>>
>>> -Acom.sun.tools.javac.sym.Dest=/java/embedded/users/dh198349/build-infra/builds/b00/se-linux-i586-ea/images/symbols/META-INF/sym/rt.jar 
>>>
>>> \
>>>             java.applet java.awt java.awt.color java.awt.datatransfer
>>> java.awt.dnd java.awt.event java.awt.font java.awt.geom java.awt.im
>>> java.awt.im.spi java.awt.image java.awt.image.renderable
>>> java.awt.print java.beans java.beans.beancontext java.io java.lang
>>> ...
>>> com.sun.servicetag com.oracle.net com.oracle.nio
>>> Error occurred during initialization of VM
>>> java/lang/UnsupportedClassVersionError: sun/misc/PostVMInitHook :
>>> Unsupported major.minor version 52.0
>>>
>>> ----
>>>
>>> Now PostVMInitHook is a class from the closed/Oracle repo. So here is
>>> what I think is happening - this closed class gets referenced but
>>> because we are on an OpenJDK build it is not found in rt.jar, but is
>>> found in our freshly built jdk/classes - hence the jdk7 VM tries to
>>> load a JDK 8 class and fails.
>>>
>>> So it would seem that an OpenJDK VM can not be used to bootstrap the
>>> Oracle JDK.
>>>
>>> Not sure there is anything we can do about that except "don't do that".
>>>
>>> David
>>> -----
>>>
>> That's what I was suspecting, that open boot cannot bootstrap Oracle 
>> JDK. Interesting that we get that far before it falls apart. This 
>> looks like it's the generation of symbol files for ct.sym. I tried to 
>> reproduce this by building an openjdk only image myself and then 
>> using it as boot for a closed build, but that didn't fail.
>>
>> Configure should try to detect if the bootjdk is unlikely to work at 
>> least.
>>
>> /Erik
>>>>
>>>> /Erik
>>>>
>>>> On 2012-12-07 00:35, David Holmes wrote:
>>>>> I've now seen two people encounter problems trying to build Profiles
>>>>> using the new build system, when their boot JDK is the locally
>>>>> installed IcedTea openjdk distribution (7 in one case and 6 in
>>>>> another).
>>>>>
>>>>> The error occurs creating jar files eg
>>>>>
>>>>> Creating resources.jar
>>>>> Error occurred during initialization of VM
>>>>> java/lang/UnsupportedClassVersionError: sun/misc/PostVMInitHook :
>>>>> Unsupported major.minor version 52.0
>>>>>
>>>>> Are we using bootclasspath tricks that only work on Oracle JDK?
>>>>>
>>>>> David
>>>>>
>>
>