RFR: JDK-8214063: OpenJDK will not build on AIX while using the xlc 13.1 compiler

Magnus Ihse Bursie magnus.ihse.bursie at oracle.com
Wed Nov 28 09:23:28 UTC 2018



On 2018-11-27 13:26, Ichiroh Takiguchi wrote:
> Hello Volker.
>
> Sorry for your confusion.
> I want to keep visibility feature on AIX platform for future OpenJDK.
>
> If I can apply workaround for AIX platform...
>
> XLC++ 13.1 is confused destructor order for ~SimpleCriticalSectionLock()
> on src/java.base/share/native/libjimage/osSupport.hpp, if visibility 
> feature is specified.
>
> Please see following testing.
> (I already applied a fix against 
> src/java.base/unix/native/include/jni_md.h)
>
> $ sh NativeImageBuffer.o.cmdline
> "/home/jdktest/sandbox/jdk/build/aix-ppc64-server-release/support/headers/java.base/jdk_internal_jimage_NativeImageBuffer.h", 
> line 15.27: 1540-0040 (S) The text 
> "Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap" is 
> unexpected.  "visibility" may be undeclared or ambiguous.
>
> If I applied following change
> ======
> $ hg di src/java.base/share/native/libjimage/osSupport.hpp
> diff -r 6cf555c2e9ff src/java.base/share/native/libjimage/osSupport.hpp
> --- a/src/java.base/share/native/libjimage/osSupport.hpp Sun Nov 25 
> 21:41:12 2018 +0900
> +++ b/src/java.base/share/native/libjimage/osSupport.hpp Tue Nov 27 
> 21:04:41 2018 +0900
> @@ -103,6 +103,7 @@
>      SimpleCriticalSection *lock;
>  public:
>
> +#ifndef _AIX
>      SimpleCriticalSectionLock(SimpleCriticalSection *cslock) {
>          this->lock = cslock;
>          lock->enter();
> @@ -111,6 +112,16 @@
>      ~SimpleCriticalSectionLock() {
>          lock->exit();
>      }
> +#else
> +    ~SimpleCriticalSectionLock() {
> +        lock->exit();
> +    }
> +
> +    SimpleCriticalSectionLock(SimpleCriticalSection *cslock) {
> +        this->lock = cslock;
> +        lock->enter();
> +    }
> +#endif
>  };
This is really fascinating! :-) Is there something in this code that 
trips up the AIX compiler? I saw that you could also "fix" it by 
removing the header file completely, or add an additional declaration. 
What if you change the order of include files? And what on earth is 
making the compiler barf on this trivial code? *intrigued*

/Magnus
>
>  #endif  // LIBJIMAGE_OSSUPPORT_HPP
> ======
>
> No output was displayed by NativeImageBuffer.o.cmdline
> $ sh NativeImageBuffer.o.cmdline
> $
>
> Adam, if possible, could you double check my code ?
>
> Volker, I appreciate if you reconsider about this issue.
>
> Thanks,
> Ichiroh Takiguchi
>
> On 2018-11-27 03:26, Volker Simonis wrote:
>> On Mon, Nov 26, 2018 at 6:52 PM Ichiroh Takiguchi
>> <takiguc at linux.vnet.ibm.com> wrote:
>>>
>>> Hello Volker.
>>>
>>> I posted same kind of fix before:
>>> http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2018-June/003551.html 
>>>
>>>
>>> I could not find out brace handling issue on XLC++ 13.1.
>>>
>>> For workaround,
>>> ======
>>> ---
>>> old/src/java.base/share/native/libjimage/NativeImageBuffer.cpp 
>>> 2018-06-07
>>> 21:06:09 +0000
>>> +++
>>> new/src/java.base/share/native/libjimage/NativeImageBuffer.cpp 
>>> 2018-06-07
>>> 21:06:09 +0000
>>> @@ -39,7 +39,9 @@
>>>   #include "imageFile.hpp"
>>>   #include "inttypes.hpp"
>>>   #include "jimage.hpp"
>>> +#if !defined(_AIX)
>>>   #include "osSupport.hpp"
>>> +#endif
>>>
>>>   #include "jdk_internal_jimage_NativeImageBuffer.h"
>>> ======
>>>
>>> I think osSupport.hpp is no need for all platform.
>>> (I tested it on Linux and AIX build)
>>>
>>> What do you think ?
>>>
>>
>> Sorry, but I don't understand your mail. Did you saw the same problems
>> like Adam when compiling "NativeImageBuffer.cpp"?
>>
>> - If yes, did you fix them by excluding the inclusion of
>> "osSupport.hpp" ? That would be strange, because it doesn't seem to
>> related to the problems reported until now at all.
>>
>> - If no, I'm totally confused...
>>
>>> Thanks,
>>> Ichiroh Takiguchi
>>> IBM Japan, Ltd.
>>>
>>> On 2018-11-27 02:06, Volker Simonis wrote:
>>> > On Mon, Nov 26, 2018 at 2:16 PM Adam Farley8 <adam.farley at uk.ibm.com>
>>> > wrote:
>>> >>
>>> >> Hi Volker,
>>> >>
>>> >> Apologies for the delay.
>>> >>
>>> >> I ran the contents of the file as requested (neat tip, thanks!) 
>>> and I
>>> >> discovered something:
>>> >>
>>> >> If jdk_internal_jimage_NativeImageBuffer.h contains this:
>>> >>
>>> >> -----
>>> >> extern "C" {
>>> >> __attribute__((visibility("default"))) jobject JNICALL
>>> >> Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap
>>> >> (JNIEnv *, jclass, jstring);
>>> >> }
>>> >> -----
>>> >>
>>> >> It results in this error:
>>> >>
>>> >> -----
>>> >> blah blah "visibility" may be undeclared or ambiguous.
>>> >> -----
>>> >>
>>> >> But replacing that bit with this code:
>>> >>
>>> >> -----
>>> >> extern "C" __attribute__((visibility("default"))) jobject JNICALL
>>> >> Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap
>>> >> (JNIEnv *, jclass, jstring);
>>> >> -----
>>> >>
>>> >> Results in no error.
>>> >>
>>> >> So it seems the difference between an "extern "C"" block and an 
>>> inline
>>> >> "extern"C"" is what's causing the issue.
>>> >>
>>> >
>>> > Thanks for finding this out. Now at least we know the root cause 
>>> of the
>>> > problem.
>>> >
>>> > Without having read through the C++ specification, I'd assume this is
>>> > a problem of XLC 13.
>>> >
>>> > As long as XLC has problems to parse such kinds of constructs, I 
>>> thing
>>> > we should just remove "-qvisibility" from the AIX build as 
>>> proposed by
>>> > Magnus (and called "plan B" in you other mail) because changing the
>>> > javah generator for AIX would be a much larger task.
>>> >
>>> > Thank you and best regards,
>>> > Volker
>>> >
>>> >> I don't understand why, but there we have it.
>>> >>
>>> >> A shame the header file is generated. An ideal fix would either 
>>> be to:
>>> >>
>>> >> 1) Change xlC to make this work inside an extern "C" block.
>>> >> or
>>> >> 2) Change the way the header file is generated to add that extern 
>>> "C"
>>> >> bit onto the line itself.
>>> >>
>>> >> However both of those have the potential to break other stuff.
>>> >>
>>> >> I'm reaching out to the xlC developers now to figure out what's 
>>> going
>>> >> on, but in the
>>> >> meantime it seems to me like the proposed fix is still the right way
>>> >> to go for a short-term
>>> >> resolution.
>>> >>
>>> >> What are your thoughts?
>>> >>
>>> >> Best Regards
>>> >>
>>> >> Adam Farley
>>> >> IBM Runtimes
>>> >>
>>> >>
>>> >> Volker Simonis <volker.simonis at gmail.com> wrote on 22/11/2018
>>> >> 14:25:04:
>>> >>
>>> >> > From: Volker Simonis <volker.simonis at gmail.com>
>>> >> > To: adam.farley at uk.ibm.com
>>> >> > Cc: Java Core Libs <core-libs-dev at openjdk.java.net>, "Stuefe,
>>> >> > Thomas" <thomas.stuefe at gmail.com>
>>> >> > Date: 22/11/2018 14:25
>>> >> > Subject: Re: RFR: JDK-8214063: OpenJDK will not build on AIX while
>>> >> > using the xlc 13.1 compiler
>>> >> >
>>> >> > On Thu, Nov 22, 2018 at 3:00 PM Adam Farley8 
>>> <adam.farley at uk.ibm.com> wrote:
>>> >> > >
>>> >> > > Hi Volker,
>>> >> > >
>>> >> > > 1) Here is the "reasonable" code in the generated
>>> >> > jdk_internal_jimage_NativeImageBuffer.h
>>> >> > >
>>> >> > > ------------------------------------------------------
>>> >> > > /* DO NOT EDIT THIS FILE - it is machine generated */
>>> >> > > #include <jni.h>
>>> >> > > /* Header for class jdk_internal_jimage_NativeImageBuffer */
>>> >> > >
>>> >> > > #ifndef _Included_jdk_internal_jimage_NativeImageBuffer
>>> >> > > #define _Included_jdk_internal_jimage_NativeImageBuffer
>>> >> > > #ifdef __cplusplus
>>> >> > > extern "C" {
>>> >> > > #endif
>>> >> > > /*
>>> >> > >  * Class: jdk_internal_jimage_NativeImageBuffer
>>> >> > >  * Method:    getNativeMap
>>> >> > >  * Signature: (Ljava/lang/String;)Ljava/nio/ByteBuffer;
>>> >> > >  */
>>> >> > > JNIEXPORT jobject JNICALL
>>> >> > Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap
>>> >> > >   (JNIEnv *, jclass, jstring);
>>> >> > >
>>> >> > > #ifdef __cplusplus
>>> >> > > }
>>> >> > > #endif
>>> >> > > #endif
>>> >> > > ------------------------------------------------------
>>> >> > >
>>> >> > >
>>> >> > > 2) I have not yet reported this as a bug to the xlc 
>>> developers. I
>>> >> > will contact
>>> >> > > them now.
>>> >> > >
>>> >> > > 3) I did some experimenting, and it seems that the
>>> >> > NativeImageBuffer.cpp change
>>> >> > > is the only thing standing between us and a successful 
>>> compilation
>>> >> > on aix using
>>> >> > > xlc 13.1 (assuming you're using source that compiles on aix 
>>> with xlc 12.1).
>>> >> > >
>>> >> > > With that change (plus the jni_md change), the compilation 
>>> completes.
>>> >> > >
>>> >> > > Without that change (after you've added the jni_md change 
>>> though),the build
>>> >> > > will fail with this error message:
>>> >> > >
>>> >> > > ------------------------------------------------------
>>> >> > > 12:19:58 "/workspace/build/aix-ppc64-normal-server-release/
>>> >> > 
>>> support/headers/java.base/jdk_internal_jimage_NativeImageBuffer.h",
>>> >> > line 15.27: 1540-0040 (S) The text
>>> >> > "Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap" is
>>> >> > unexpected.  "visibility" may be undeclared or ambiguous.
>>> >> > > 12:19:59 CoreLibraries.gmk:192: recipe for target '/workspace/
>>> >> > build/aix-ppc64-normal-server-release/support/native/java.base/
>>> >> > libjimage/NativeImageBuffer.o' failed
>>> >> > > ------------------------------------------------------
>>> >> > >
>>> >> >
>>> >> > Can you please do the following:
>>> >> >  - take the command line from
>>> >> > /workspace/build/aix-ppc64-normal-server-release/support/native/
>>> >> > java.base/libjimage/NativeImageBuffer.o.cmdline
>>> >> >  - replace '-c' with '-E' to get the preprocessor output
>>> >> >  - have a look at the offending line (e.g. have JNIEXPORT / 
>>> JNICALL
>>> >> > been correctly expanded ?)
>>> >> >
>>> >> > Unfortunately I don't have a version of XLC 13 to test this.
>>> >> >
>>> >> > > Best Regards
>>> >> > >
>>> >> > > Adam Farley
>>> >> > > IBM Runtimes
>>> >> > >
>>> >> > > P.S. Tried making a small, stand-alone example and it failed to
>>> >> > reproduce the problem.
>>> >> > > Will keep trying, and I'll supply a further update in the 
>>> event of
>>> >> > a) results,
>>> >> > > or b) a response from the xlc guys.
>>> >> > >
>>> >> > >
>>> >> > > Volker Simonis <volker.simonis at gmail.com> wrote on 21/11/2018 
>>> 14:07:07:
>>> >> > >
>>> >> > > > From: Volker Simonis <volker.simonis at gmail.com>
>>> >> > > > To: adam.farley at uk.ibm.com
>>> >> > > > Cc: Java Core Libs <core-libs-dev at openjdk.java.net>, "Stuefe,
>>> >> > > > Thomas" <thomas.stuefe at gmail.com>
>>> >> > > > Date: 21/11/2018 14:07
>>> >> > > > Subject: Re: RFR: JDK-8214063: OpenJDK will not build on 
>>> AIX while
>>> >> > > > using the xlc 13.1 compiler
>>> >> > > >
>>> >> > > > On Wed, Nov 21, 2018 at 1:46 PM Adam Farley8
>>> >> > <adam.farley at uk.ibm.com> wrote:
>>> >> > > > >
>>> >> > > > > Hi Volker,
>>> >> > > > >
>>> >> > > > > The NativeImageBuffer.cpp changes are best explained by 
>>> the full text of
>>> >> > > > > the referenced GitHub Pull Request, copied here for 
>>> simplicity:
>>> >> > > > >
>>> >> > > > > -----------------------------------------
>>> >> > > > > Define JNIEXPORT and JNIIMPORT for xlc version 13.1 or 
>>> newer.
>>> >> > Without this,
>>> >> > > > > almost no symbols are exported from shared libraries due 
>>> to use of
>>> >> > > > > -qvisibility=hidden as specified in 
>>> make/lib/LibCommon.gmk. The symptoms
>>> >> > > > > are reported in eclipse/openj9#2468.
>>> >> > > > >
>>> >> > > > > Unfortunately, this encounters a bug in xlc: it fails to 
>>> parsewhat seems
>>> >> > > > > to be reasonable code.
>>> >> > > >
>>> >> > > > Sorry, but I don't see how this answers my question.
>>> >> > > >
>>> >> > > > 1. Which "reasonable code" does xlc fails to parse. A 
>>> stand-alone
>>> >> > > > example would be nice.
>>> >> > > >
>>> >> > > > 2. Have you reported this as bug to the xlc developers? 
>>> What didthey say?
>>> >> > > >
>>> >> > > > 3. "jdk_internal_jimage_NativeImageBuffer.h" doesn't seem 
>>> to be
>>> >> > > > special. It's a plain, generated JNI header file as 
>>> generated by
>>> >> > > > 'javah' or 'javac -h'. If XLC 13 has problems parsing it, 
>>> there should
>>> >> > > > be much more places which need fixing. So what's special about
>>> >> > > > "jdk_internal_jimage_NativeImageBuffer.h".
>>> >> > > >
>>> >> > > > In the referenced pull request
>>> >> > > > (https://urldefense.proofpoint.com/v2/url?
>>> >> > > >
>>> >> > 
>>> u=https-3A__github.com_eclipse_openj9_issues_2468&d=DwIFaQ&c=jf_iaSHvJObTbx-
>>> >> > > > siA1ZOg&r=P5m8KWUXJf-
>>> >> > > >
>>> >> > 
>>> CeVJc0hDGD9AQ2LkcXDC0PMV9ntVw5Ho&m=sgfFd6mB1EYM4nOM89rgFFzUyX7B21XbckIY7L0kUNU&s=TJ-4nr8ikZKImwDygirRTxLybsnQWBN71nEZCwZ59NQ&e=
>>> >> > > > ) I can only see linker
>>> >> > > > errors (and no compiler errors). The linker errors are for 
>>> both
>>> >> > > > libjsig and libjava. They are related to the symbol 
>>> ".sigaction" in
>>> >> > > > jsig.o and I don't see how this should be related to
>>> >> > > > NativeImageBuffer.cpp or 
>>> "jdk_internal_jimage_NativeImageBuffer.h".
>>> >> > > > NativeImageBuffer.cpp is only used to create libjimage and 
>>> not related
>>> >> > > > in any way to libjsig or libjava.
>>> >> > > >
>>> >> > > > It seems wired to do the change to NativeImageBuffer.cpp 
>>> which you've
>>> >> > > > proposed without understanding the real cause of the problem.
>>> >> > > >
>>> >> > > > Regards,
>>> >> > > > Volker
>>> >> > > >
>>> >> > > > > A workaround is required in just one place:
>>> >> > > > > src/java.base/share/native/libjimage/NativeImageBuffer.cpp.
>>> >> > > > > -----------------------------------------
>>> >> > > > >
>>> >> > > > > Best Regards
>>> >> > > > >
>>> >> > > > > Adam Farley
>>> >> > > > > IBM Runtimes
>>> >> > > > >
>>> >> > > > >
>>> >> > > > > Volker Simonis <volker.simonis at gmail.com> wrote on 
>>> 20/11/2018 17:50:41:
>>> >> > > > >
>>> >> > > > > > From: Volker Simonis <volker.simonis at gmail.com>
>>> >> > > > > > To: "Stuefe, Thomas" <thomas.stuefe at gmail.com>
>>> >> > > > > > Cc: adam.farley at uk.ibm.com, Java Core Libs <core-libs-
>>> >> > > > dev at openjdk.java.net>
>>> >> > > > > > Date: 20/11/2018 17:59
>>> >> > > > > > Subject: Re: RFR: JDK-8214063: OpenJDK will not build 
>>> on AIX while
>>> >> > > > > > using the xlc 13.1 compiler
>>> >> > > > > >
>>> >> > > > > > On Tue, Nov 20, 2018 at 6:15 PM Thomas Stüfe
>>> >> > > > <thomas.stuefe at gmail.com> wrote:
>>> >> > > > > > >
>>> >> > > > > > > On Tue, Nov 20, 2018 at 6:12 PM Adam Farley8
>>> >> > > > <adam.farley at uk.ibm.com> wrote:
>>> >> > > > > > > >
>>> >> > > > > > > > Heya Tom,
>>> >> > > > > > > >
>>> >> > > > > > > > "In JDK11 and JDK12, source files are compiled with -
>>> >> > > > qvisibility=hidden
>>> >> > > > > > > > when using xlc version other than 12.1. That doesn't
>>> >> > seem toplay well
>>> >> > > > > > > > with link option -bexpall. "
>>> >> > > > > > > >
>>> >> > > > > > > > Found that buried in one of the associated Git issues.
>>> >> > It appears that
>>> >> > > > > > > > it's OpenJDK's use of that option that's causing the
>>> >> > problem, though
>>> >> > > > > > > > I couldn't speculate as to why it was added in the 
>>> first place.
>>> >> > > > > > > >
>>> >> > > > > > > > I see this has also been noted in https://
>>> >> > > > > > urldefense.proofpoint.com/v2/url?
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> u=https-3A__bugs.openjdk.java.net_browse_JDK-2D8204541&d=DwIFaQ&c=jf_iaSHvJObTbx-
>>> >> > > > > > siA1ZOg&r=P5m8KWUXJf-
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> CeVJc0hDGD9AQ2LkcXDC0PMV9ntVw5Ho&m=SD6UdjysISJRBlWUm8pEzF5lRZ5opfbrKzEh_jrOras&s=5qDEdIfg8qZ-
>>> >> > > > > > vCglsZ9qNDTEPMnCkj-mVPVah6eEDLE&e=
>>> >> > > > > > > >
>>> >> > > > > > > > Does that answer your question?
>>> >> > > > > > > >
>>> >> > > > > > >
>>> >> > > > > > > Yes, Thank you. Odd. Will have to do archeology on 
>>> that one.
>>> >> > > > > > >
>>> >> > > > > >
>>> >> > > > > > No I begin to understand the problem as well :)
>>> >> > > > > >
>>> >> > > > > > It was actually change "8202322: AIX: symbol visibility 
>>> flags not
>>> >> > > > > > support on xlc 12.1" [1] which introduced 
>>> "-qvisibility=hidden" for
>>> >> > > > > > XLC version not equal to 12.1. That's kind of a weak 
>>> check and I
>>> >> > > > > > suppose nobody has ever tested this change with an XLC 
>>> version other
>>> >> > > > > > than 12.1 (until you came along :). Maybe that check 
>>> should be a more
>>> >> > > > > > precisly check for >= 13.1 (but I know such version 
>>> checks are hard to
>>> >> > > > > > do in Makefile syntax)?
>>> >> > > > > >
>>> >> > > > > > The thing I don't understand about your patch (the 
>>> changes in
>>> >> > > > > > "jni_md.h" look good although I haven't tested them) is 
>>> why you need
>>> >> > > > > > the extra changes in NativeImageBuffer.cpp?
>>> >> > > > > > "jdk_internal_jimage_NativeImageBuffer.h" is a plain, 
>>> generated JNI
>>> >> > > > > > header file. If XLC 13 has problems to parse it, there 
>>> should be much
>>> >> > > > > > more places which need fixing. I think that part of 
>>> your change needs
>>> >> > > > > > a closer evaluation.
>>> >> > > > > >
>>> >> > > > > > Thank you and best regards,
>>> >> > > > > > Volker
>>> >> > > > > >
>>> >> > > > > > [1] https://urldefense.proofpoint.com/v2/url?
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> u=https-3A__bugs.openjdk.java.net_browse_JDK-2D8202322&d=DwIFaQ&c=jf_iaSHvJObTbx-
>>> >> > > > > > siA1ZOg&r=P5m8KWUXJf-
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> CeVJc0hDGD9AQ2LkcXDC0PMV9ntVw5Ho&m=SD6UdjysISJRBlWUm8pEzF5lRZ5opfbrKzEh_jrOras&s=JAEK6rePGMPinZzOquHBzj5oc7vA3kaFt9x0WIIUzvk&e=
>>> >> > > > > >
>>> >> > > > > > > ..Thomas
>>> >> > > > > > >
>>> >> > > > > > > > Best Regards
>>> >> > > > > > > >
>>> >> > > > > > > > Adam Farley
>>> >> > > > > > > > IBM Runtimes
>>> >> > > > > > > >
>>> >> > > > > > > >
>>> >> > > > > > > > "Thomas Stüfe" <thomas.stuefe at gmail.com> wrote on 
>>> 20/11/
>>> >> > 201816:44:07:
>>> >> > > > > > > >
>>> >> > > > > > > > > From: "Thomas Stüfe" <thomas.stuefe at gmail.com>
>>> >> > > > > > > > > To: Adam Farley8 <adam.farley at uk.ibm.com>
>>> >> > > > > > > > > Cc: Java Core Libs <core-libs-dev at openjdk.java.net>
>>> >> > > > > > > > > Date: 20/11/2018 16:48
>>> >> > > > > > > > > Subject: Re: RFR: JDK-8214063: OpenJDK will not 
>>> build
>>> >> > on AIX while
>>> >> > > > > > > > > using the xlc 13.1 compiler
>>> >> > > > > > > > >
>>> >> > > > > > > > > Hi Adam,
>>> >> > > > > > > > >
>>> >> > > > > > > > > On Tue, Nov 20, 2018 at 5:12 PM Adam Farley8
>>> >> > > > > > <adam.farley at uk.ibm.com> wrote:
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > Hi Tom,
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > Sounds reasonable. I've added a webex to the 
>>> bug, and here's a
>>> >> > > > > > > > > link to the bug.
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > https://urldefense.proofpoint.com/v2/url?
>>> >> > > > > > > > >
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> u=https-3A__bugs.openjdk.java.net_browse_JDK-2D8214063&d=DwIFaQ&c=jf_iaSHvJObTbx-
>>> >> > > > > > > > > siA1ZOg&r=P5m8KWUXJf-
>>> >> > > > > > > > >
>>> >> > > > > >
>>> >> > > >
>>> >> > 
>>> CeVJc0hDGD9AQ2LkcXDC0PMV9ntVw5Ho&m=z8YYwBXEfN7UtX1suPjpp9CZSHf8v0GrIMK3XGIC9VY&s=81TP9mIjhYD2Hmt8g7p2EHWRZXgiep21hxKLYRU7zIQ&e=
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > This patch is required because otherwise, when 
>>> building on AIX
>>> >> > > > > > > > > using xlc 3.1,
>>> >> > > > > > > > > > the build fails with this error:
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > "Visibility is not allowed on a reference to an
>>> >> > imported symbol."
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > We believe this is caused by JNIEXPORT and 
>>> JNIIMPORTnot being
>>> >> > > > > > > > > defined. Without
>>> >> > > > > > > > > > this, almost no symbols are exported from 
>>> shared libraries
>>> >> > > > > > due to use of
>>> >> > > > > > > > > > -qvisibility=hidden as specified in 
>>> make/lib/LibCommon.gmk.
>>> >> > > > > > > > >
>>> >> > > > > > > > > Yes but what I try to understand is why does this
>>> >> > happen now with
>>> >> > > > > > > > > xlc13? Did xlc change the rules for -qvisibility 
>>> from
>>> >> > v12 to v13 ?
>>> >> > > > > > > > > That would be quite a break in backward 
>>> compatibility.
>>> >> > > > > > > > >
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > For convenience, here's a summary of the diffs:
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > --------------------------------------
>>> >> > > > > > > > > > File 1 of 2) src/java.base/share/native/libjimage/
>>> >> > > > > > NativeImageBuffer.cpp
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > #include "osSupport.hpp"
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > +#if defined(__xlC__) && (__xlC__ >= 0x0d01)
>>> >> > > > > > > > > > +/*
>>> >> > > > > > > > > > + * Version 13.1.3 of xlc seems to have trouble 
>>> parsing the
>>> >> > > > > > `__attribute__`
>>> >> > > > > > > > > > + * annotation in the generated header file 
>>> we're about to
>>> >> > > > > > > > > include. Repeating
>>> >> > > > > > > > > > + * the forward declaration (without the 
>>> braces) here avoids
>>> >> > > > > > the diagnostic:
>>> >> > > > > > > > > > + * 1540-0040 (S) The text "void" is unexpected.
>>> >> > "visibility"
>>> >> > > > > > > > > may be undeclared or ambiguous.
>>> >> > > > > > > > > > + */
>>> >> > > > > > > > > > +extern "C" JNIEXPORT jobject JNICALL
>>> >> > > > > > > > >
>>> >> > Java_jdk_internal_jimage_NativeImageBuffer_getNativeMap(JNIEnv *,
>>> >> > > > > > > > > jclass, jstring);
>>> >> > > > > > > > > > +#endif
>>> >> > > > > > > > > > +
>>> >> > > > > > > > > > #include "jdk_internal_jimage_NativeImageBuffer.h"
>>> >> > > > > > > > > > --------------------------------------
>>> >> > > > > > > > > > File 2 of 2) 
>>> src/java.base/unix/native/include/jni_md.h
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > #define JNIIMPORT     __attribute__((visibility
>>> >> > ("default")))
>>> >> > > > > > > > > >   #endif
>>> >> > > > > > > > > > +#elif defined(__xlC__) && (__xlC__ >= 0x0d01) /*
>>> >> > xlc version 13.1
>>> >> > > > > > > > > or better required */
>>> >> > > > > > > > > > + #define JNIEXPORT       
>>> __attribute__((visibility
>>> >> > ("default")))
>>> >> > > > > > > > > > + #define JNIIMPORT       
>>> __attribute__((visibility
>>> >> > ("default")))
>>> >> > > > > > > > > > #else
>>> >> > > > > > > > > > #define JNIEXPORT
>>> >> > > > > > > > > > --------------------------------------
>>> >> > > > > > > > > >
>>> >> > > > > > > > >
>>> >> > > > > > > > > Thank you.
>>> >> > > > > > > > >
>>> >> > > > > > > > > Cheers, Thomas
>>> >> > > > > > > > >
>>> >> > > > > > > > > > Best Regards
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > Adam Farley
>>> >> > > > > > > > > > IBM Runtimes
>>> >> > > > > > > > > >
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > "Thomas Stüfe" <thomas.stuefe at gmail.com> wrote 
>>> on 19/11/
>>> >> > > > 201818:11:34:
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > > From: "Thomas Stüfe" <thomas.stuefe at gmail.com>
>>> >> > > > > > > > > > > To: Adam Farley8 <adam.farley at uk.ibm.com>
>>> >> > > > > > > > > > > Cc: Java Core Libs 
>>> <core-libs-dev at openjdk.java.net>
>>> >> > > > > > > > > > > Date: 19/11/2018 18:12
>>> >> > > > > > > > > > > Subject: Re: RFR: JDK-8214063: OpenJDK will 
>>> not build
>>> >> > > > on AIX while
>>> >> > > > > > > > > > > using the xlc 13.1 compiler
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > Hi Adam,
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > could you please include link to the JBS 
>>> issue and either
>>> >> > > > > > link to the
>>> >> > > > > > > > > > > patch/webrev or link to the webrev, or at the 
>>> very
>>> >> > > > least the patch
>>> >> > > > > > > > > > > verbatim?
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > As for the issue itself: could you please 
>>> elaborate why this
>>> >> > > > > > > > > fails with xlc13?
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > Also, a real patch would be helpful instead 
>>> here of
>>> >> > > > yet another link
>>> >> > > > > > > > > > > to some J9 issue. We are really strapped for 
>>> manpower and
>>> >> > > > > > the AIX port
>>> >> > > > > > > > > > > eats up enough time as it is.
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > Thanks, Thomas
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > > > On Mon, Nov 19, 2018 at 6:28 PM Adam Farley8
>>> >> > > > > > > > > <adam.farley at uk.ibm.com> wrote:
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Hi All
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Both the problem and the solution appear 
>>> straight-
>>> >> > > > forward enough.
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Details included in the bug description.
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Thoughts and opinions welcome.
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Best Regards
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Adam Farley
>>> >> > > > > > > > > > > > IBM Runtimes
>>> >> > > > > > > > > > > >
>>> >> > > > > > > > > > > > Unless stated otherwise above:
>>> >> > > > > > > > > > > > IBM United Kingdom Limited - Registered in 
>>> England and
>>> >> > > > > > Wales with number
>>> >> > > > > > > > > > > > 741598.
>>> >> > > > > > > > > > > > Registered office: PO Box 41, North 
>>> Harbour, Portsmouth,
>>> >> > > > > > > > > Hampshire PO6 3AU
>>> >> > > > > > > > > > >
>>> >> > > > > > > > > >
>>> >> > > > > > > > > > Unless stated otherwise above:
>>> >> > > > > > > > > > IBM United Kingdom Limited - Registered in England
>>> >> > and Wales with
>>> >> > > > > > > > > number 741598.
>>> >> > > > > > > > > > Registered office: PO Box 41, North Harbour, 
>>> Portsmouth,
>>> >> > > > > > Hampshire PO6 3AU
>>> >> > > > > > > > >
>>> >> > > > > > > >
>>> >> > > > > > > > Unless stated otherwise above:
>>> >> > > > > > > > IBM United Kingdom Limited - Registered in England 
>>> and Wales
>>> >> > > > > > with number 741598.
>>> >> > > > > > > > Registered office: PO Box 41, North Harbour, 
>>> Portsmouth,
>>> >> > > > Hampshire PO6 3AU
>>> >> > > > > >
>>> >> > > > >
>>> >> > > > > Unless stated otherwise above:
>>> >> > > > > IBM United Kingdom Limited - Registered in England and 
>>> Wales with
>>> >> > > > number 741598.
>>> >> > > > > Registered office: PO Box 41, North Harbour, Portsmouth,
>>> >> > Hampshire PO6 3AU
>>> >> > > >
>>> >> > >
>>> >> > > Unless stated otherwise above:
>>> >> > > IBM United Kingdom Limited - Registered in England and Wales 
>>> with
>>> >> > number 741598.
>>> >> > > Registered office: PO Box 41, North Harbour, Portsmouth, 
>>> Hampshire PO6 3AU
>>> >> >
>>> >>
>>> >> Unless stated otherwise above:
>>> >> IBM United Kingdom Limited - Registered in England and Wales with
>>> >> number 741598.
>>> >> Registered office: PO Box 41, North Harbour, Portsmouth, 
>>> Hampshire PO6
>>> >> 3AU
>>>
>



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