RFR : 8204541 Correctly support AIX xlC 13.1 symbol visibility flags

Ichiroh Takiguchi takiguc at linux.vnet.ibm.com
Thu Jun 7 16:29:09 UTC 2018 

Hello Christoph

According to build log, if <#include "osSupport.hpp"> was there:
"/home/jdktest/sandbox/jdk/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.
make[3]: *** 
[/home/jdktest/sandbox/jdk/build/aix-ppc64-normal-server-release/support/native/java.base/libjimage/NativeImageBuffer.o] 
Error 1
make[3]: Leaving directory `/home/jdktest/sandbox/jdk/make'
make[2]: *** [java.base-libs] Error 2
make[2]: *** Waiting for unfinished jobs....

On 2018-06-07 22:06, Langer, Christoph wrote:
> 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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