RFR : 8204541 Correctly support AIX xlC 13.1 symbol visibility flags

Langer, Christoph christoph.langer at sap.com
Thu Jun 7 13:06:42 UTC 2018 

Hi Ichiroh,

what's the exact error message if you  #include "osSupport.hpp"? (I have no xlC 13 at hand to try myself...)

Best regards
Christoph

> -----Original Message-----
> From: Ichiroh Takiguchi [mailto:takiguc at linux.vnet.ibm.com]
> Sent: Donnerstag, 7. Juni 2018 14:53
> To: build-dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net; core-
> libs-dev at openjdk.java.net
> Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Baesken, Matthias
> <matthias.baesken at sap.com>; Langer, Christoph
> <christoph.langer at sap.com>
> Subject: RFR : 8204541 Correctly support AIX xlC 13.1 symbol visibility flags
> 
> Hello.
> 
> Could you review it ?
> Bug:    https://bugs.openjdk.java.net/browse/JDK-8204541
> Change: http://cr.openjdk.java.net/~clanger/webrevs/8204541.0/
> 
> Thanks,
> Ichiroh Takiguchi
> IBM Japan, Ltd.
> 
> -------- Original Message --------
> Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on
> xlc 12.1
> Date: 2018-06-07 20:43
>  From: "Langer, Christoph" <christoph.langer at sap.com>
> To: Ichiroh Takiguchi <takiguc at linux.vnet.ibm.com>
> Cc: "'build-dev at openjdk.java.net'" <build-dev at openjdk.java.net>,
> "ppc-aix-port-dev at openjdk.java.net" <ppc-aix-port-
> dev at openjdk.java.net>,
> "core-libs-dev at openjdk.java.net" <core-libs-dev at openjdk.java.net>,
> "Lindenmaier, Goetz" <goetz.lindenmaier at sap.com>, "Baesken, Matthias"
> <matthias.baesken at sap.com>
> 
> Hi Ichiroh,
> 
> your proposal seems to make sense. I have created a bug for this:
> https://bugs.openjdk.java.net/browse/JDK-8204541
> 
> Can you please generate a webrev (referencing this bug, -c option of
> webrev.ksh) and mail it over to me. Then I'll upload it and you can post
> an official RFR mail.
> 
> Best regards
> Christoph
> 
> > -----Original Message-----
> > From: Ichiroh Takiguchi [mailto:takiguc at linux.vnet.ibm.com]
> > Sent: Dienstag, 5. Juni 2018 08:59
> > To: Baesken, Matthias <matthias.baesken at sap.com>
> > Cc: Langer, Christoph <christoph.langer at sap.com>; 'build-
> > dev at openjdk.java.net' <build-dev at openjdk.java.net>; ppc-aix-port-
> > dev at openjdk.java.net; core-libs-dev at openjdk.java.net; Lindenmaier,
> > Goetz <goetz.lindenmaier at sap.com>
> > Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on
> > xlc 12.1
> >
> > Hello Matthias and Christoph.
> > Thank you for your explanations.
> >
> > I did not have enough knowledge about "visibility".
> >
> > I created following patches.
> >
> > ================================
> > diff -r 02934b0d661b
> > src/java.base/share/native/libjimage/NativeImageBuffer.cpp
> > --- a/src/java.base/share/native/libjimage/NativeImageBuffer.cpp	Wed
> > May
> > 30 14:46:28 2018 +0200
> > +++ b/src/java.base/share/native/libjimage/NativeImageBuffer.cpp
> 	Tue
> > Jun
> > 05 12:10:41 2018 +0900
> > @@ -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"
> >
> > diff -r 02934b0d661b src/java.base/unix/native/include/jni_md.h
> > --- a/src/java.base/unix/native/include/jni_md.h	Wed May 30 14:46:28
> > 2018 +0200
> > +++ b/src/java.base/unix/native/include/jni_md.h	Tue Jun 05 12:10:41
> > 2018 +0900
> > @@ -29,7 +29,8 @@
> >   #ifndef __has_attribute
> >     #define __has_attribute(x) 0
> >   #endif
> > -#if (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4) &&
> > (__GNUC_MINOR__ > 2))) || __has_attribute(visibility)
> > +#if (defined(__GNUC__) && ((__GNUC__ > 4) || (__GNUC__ == 4) &&
> > (__GNUC_MINOR__ > 2))) || __has_attribute(visibility) \
> > +    || (defined(_AIX) && (defined(__xlC__) && (__xlC__ >= 0xD01)))
> >     #ifdef ARM
> >       #define JNIEXPORT
> > __attribute__((externally_visible,visibility("default")))
> >       #define JNIIMPORT
> > __attribute__((externally_visible,visibility("default")))
> > ================================
> >
> > If "osSupport.hpp" was included, XLC++ compiler complained.
> > I could not understand, which part was invalid...
> > I'm not sure, "osSupport.hpp" is really required on
> > NativeImageBuffer.cpp or not...
> >
> > I added __xlC__ macro to determine XLC/C++'s version# into jni_md.h.
> > [1]
> > 0xD01 means 13.1 by hexadecimal.
> >
> > I checked symbol table by "dump -Tv -X64". [2]
> > It seemed it was fine, some symbols were hidden.
> >
> > Does someone review my code?
> >
> > [1]
> >
> https://www.ibm.com/support/knowledgecenter/en/SSGH2K_13.1.3/com.i
> > bm.xlc1313.aix.doc/compiler_ref/xlmacros.html
> > [2]
> > https://www.ibm.com/developerworks/aix/library/au-aix-symbol-
> > visibility/index.html
> >
> > On 2018-06-01 21:12, Baesken, Matthias wrote:
> > > Hi ,  my change  8202322   just  handled  the fact   that  the
> > > visibility - flags   are not supported  with  xlc 12.1  ,  so  setting
> > > them generated a TON of compile - time  warnings .
> > >
> > > The introduction of   the  "-qvisibility=hidden"    came with the
> > > mapfile removal changes :
> > >
> > > 8200358: Remove mapfiles for JDK executables
> > > http://hg.openjdk.java.net/jdk/jdk/rev/210cf224b690
> > >
> > > 8200178: Remove mapfiles for JDK native libraries
> > > http://hg.openjdk.java.net/jdk/jdk/rev/396ea30afbd5
> > >
> > > I guess it  might  need further  testing+adjustments  to make  the
> > > "visibility hiding" work nicely   with XLC13  ,  but currently  we
> > > build only with XLC12 .
> > >
> > > As a workaround  you might want to  remove  the  "-qvisibility=hidden"
> > >  setting for XLC 13 as well  ,  like I did  for XLC12 with  the change
> > >   8202322   .
> > >
> > >
> > > Best regards, Matthias
> > >
> > >
> > >
> > >
> > >> -----Original Message-----
> > >> From: Langer, Christoph
> > >> Sent: Freitag, 1. Juni 2018 10:57
> > >> To: Ichiroh Takiguchi <takiguc at linux.vnet.ibm.com>
> > >> Cc: Baesken, Matthias <matthias.baesken at sap.com>; 'build-
> > >> dev at openjdk.java.net' <build-dev at openjdk.java.net>; ppc-aix-port-
> > >> dev at openjdk.java.net; core-libs-dev at openjdk.java.net; Lindenmaier,
> > >> Goetz <goetz.lindenmaier at sap.com>
> > >> Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support
> > >> on xlc 12.1
> > >>
> > >> Hi Ichiroh,
> > >>
> > >> we do not use the XLC 13 compiler on AIX yet here at SAP and I believe
> > >> nobody of my colleagues has played with it yet. So you are on a new
> > >> playground here 😊
> > >>
> > >> However, I believe the idea in OpenJDK with the abolition of map files
> > >> is that
> > >> symbols should be invisible externally unless they are declared
> > >> exported,
> > >> e.g. JNIEXPORT. So I would think "-qvisibility=hidden" should be the
> > >> correct
> > >> default and whatever JNIEXPORT expands to should contain the right
> > >> attributes to get that symbol visible.
> > >>
> > >> Can you check if either my assumption is completely wrong, JNIEXPORT
> > >> does
> > >> not expand to the right thing, XLC 13 has a bug or maybe just sume
> > >> specific
> > >> required symbols are not declared correctly?
> > >>
> > >> Best regards
> > >> Christoph
> > >>
> > >> > -----Original Message-----
> > >> > From: Ichiroh Takiguchi [mailto:takiguc at linux.vnet.ibm.com]
> > >> > Sent: Donnerstag, 31. Mai 2018 09:55
> > >> > To: Langer, Christoph <christoph.langer at sap.com>
> > >> > Cc: Baesken, Matthias <matthias.baesken at sap.com>; 'build-
> > >> > dev at openjdk.java.net' <build-dev at openjdk.java.net>; ppc-aix-port-
> > >> > dev at openjdk.java.net; core-libs-dev at openjdk.java.net;
> Lindenmaier,
> > >> > Goetz <goetz.lindenmaier at sap.com>
> > >> > Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on
> xlc
> > 12.1
> > >> >
> > >> > Hello.
> > >> > 8202322 was integrated into jdk-11+15.
> > >> > I'm using XLC 13.1.3 on AIX 7.1.4.
> > >> > Build was failed because of "-qvisibility=hidden" on
> > >> > make/lib/LibCommon.gmk.
> > >> > According to "XL C/C++ for AIX 13.1.3" documentation [1],
> > >> > "-qvisibility=hidden" cannot create shared libraries entry points.
> > >> > For example, libverify.so was there, but entry points were not
> resolved
> > >> > by "-lverify" option.
> > >> > I think it should be "-qvisibility=default" (I tried, it worked)
> > >> > or "-qvisibility=protected" (I had not tried) ?
> > >> > I'm not familiar with -qvisibility option, but I'd like to find out
> > >> > right way.
> > >> >
> > >> > [1]
> > >> >
> > >>
> >
> https://www.ibm.com/support/knowledgecenter/SSGH3R_13.1.3/com.ibm.
> > >> > xlcpp1313.aix.doc/compiler_ref/opt_visibility.html
> > >> >
> > >> > On 2018-05-16 16:08, Langer, Christoph wrote:
> > >> > > Hi Matthias,
> > >> > >
> > >> > > yes, reviewed.
> > >> > >
> > >> > > Best regards
> > >> > > Christoph
> > >> > >
> > >> > > From: Baesken, Matthias
> > >> > > Sent: Mittwoch, 16. Mai 2018 09:06
> > >> > > To: Langer, Christoph <christoph.langer at sap.com>;
> > >> > > 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>;
> > >> > > ppc-aix-port-dev at openjdk.java.net; core-libs-
> dev at openjdk.java.net
> > >> > > Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>
> > >> > > Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on
> > >> > > xlc 12.1
> > >> > >
> > >> > > Hi  Christoph can I add you as second reviewer  (other reviewer was
> > >> > > Erik Joelsson) can push the change ?
> > >> > >
> > >> > > Best regards, Matthias
> > >> > >
> > >> > >
> > >> > >
> > >> > > From: Langer, Christoph
> > >> > > Sent: Donnerstag, 26. April 2018 16:38
> > >> > > To: Baesken, Matthias
> > >> > >
> <matthias.baesken at sap.com<mailto:matthias.baesken at sap.com>>;
> > >> > > 'build-dev at openjdk.java.net'
> > >> > > <build-dev at openjdk.java.net<mailto:build-
> > dev at openjdk.java.net>>;
> > >> > > ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-
> > >> > dev at openjdk.java.net>;
> > >> > > core-libs-dev at openjdk.java.net<mailto:core-libs-
> > >> dev at openjdk.java.net>
> > >> > > Cc: Simonis, Volker
> > >> > > <volker.simonis at sap.com<mailto:volker.simonis at sap.com>>
> > >> > > Subject: RE: RFR : 8202322: AIX: symbol visibility flags not support on
> > >> > > xlc 12.1
> > >> > >
> > >> > > Hi Matthias,
> > >> > >
> > >> > > to me the change in principal looks good.
> > >> > >
> > >> > > I'm wondering if it is possible to do a comparison like xlc < 13 (e.g.
> > >> > > extract major number before the first dot, then compare
> numerically)
> > -
> > >> > > but maybe it is too complicated and the current single version
> > compare
> > >> > > suits our needs ?
> > >> > >
> > >> > > Best regards
> > >> > > Christoph
> > >> > >
> > >> > > From: Baesken, Matthias
> > >> > > Sent: Donnerstag, 26. April 2018 16:14
> > >> > > To: 'build-dev at openjdk.java.net'
> > >> > > <build-dev at openjdk.java.net<mailto:build-
> > dev at openjdk.java.net>>;
> > >> > > ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-
> > >> > dev at openjdk.java.net>;
> > >> > > core-libs-dev at openjdk.java.net<mailto:core-libs-
> > >> dev at openjdk.java.net>
> > >> > > Cc: Langer, Christoph
> > >> > > <christoph.langer at sap.com<mailto:christoph.langer at sap.com>>;
> > >> Simonis,
> > >> > > Volker
> <volker.simonis at sap.com<mailto:volker.simonis at sap.com>>
> > >> > > Subject: RFR : 8202322: AIX: symbol visibility flags not support on xlc
> > >> > > 12.1
> > >> > >
> > >> > > Hello  ,  could you please review this small adjustment to  the symbol
> > >> > > visibility compilation settings on AIX ?
> > >> > > Currently  we use  XLC 12.1  to compile  JDK on AIX .
> > >> > >
> > >> > > However XLC 12.1   does not support  the "-qvisibility=hidden"
> > >> > > setting currently set on AIX.
> > >> > > It was introduced with  XLC 13.1 . Christoph found some info about it
> > >> > > here :
> > >> > >
> > >> > > https://www.ibm.com/developerworks/aix/library/au-aix-symbol-
> > >> > visibility-part2/index.html
> > >> > >
> > >> > > Setting it  only generates  hundreds  of warnings  in the build log ,
> > >> > > warnings look like this :
> > >> > > XlC12.1
> > >> > >
> > >> > > bash-4.4$ xlC -qversion
> > >> > > IBM XL C/C++ for AIX, V12.1 (5765-J02, 5725-C72)
> > >> > > Version: 12.01.0000.0019
> > >> > >
> > >> > > bash-4.4$ xlC -qvisibility=hidden sizeof.c -o sizeof_aixxlc
> > >> > > 1506-173 (W) Option visibility=hidden is not valid. Enter xlC for list
> > >> > > of valid options.
> > >> > >
> > >> > > Compare to XLC13.1
> > >> > >
> > >> > > bash-3.00$ xlC -qversion
> > >> > > IBM XL C/C++ for AIX, V13.1 (5725-C72, 5765-J07)
> > >> > > Version: 13.01.0000.0008
> > >> > > bash-3.00$ xlC -qvisibility=default sizeof.c -o sizeof_aixxlc
> > >> > > bash-3.00$ xlC -qvisibility=hidden sizeof.c -o sizeof_aixxlc
> > >> > >
> > >> > >
> > >> > > So it is better to avoid  setting these flags when using xlc12.1   .
> > >> > > Please review :
> > >> > >
> > >> > > Bug :
> > >> > >
> > >> > > https://bugs.openjdk.java.net/browse/JDK-8202322
> > >> > >
> > >> > > Change :
> > >> > >
> > >> > > http://cr.openjdk.java.net/~mbaesken/webrevs/8202322/
> > >> > >
> > >> > >
> > >> > > Best regards, Matthias

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