Hi, FYI, if one wants to debug this issue, below is some sctripts I used to cross compile a mips zero jdk, which can trigger the bug.
build machine: x86, debian testing (in a VirtualBox; an ubuntu may fail to configure) known worked targets: ppc64le/server and s390x/server (aarch64/server may fail during make images) repository: http://hg.openjdk.java.net/jdk/jdk geting a sysroot: #export arch=arm64 #export arch=ppc64el #export arch=s390x export arch=mips64el export ver=stretch apt-get install qemu-user-static sudo debootstrap binfmt-support qemu (not sure if all of them are required) sudo qemu-debootstrap --arch=${arch} --verbose \ --include=fakeroot,build-essential,libx11-dev,libxext-dev,libxrender-dev,libxrandr-dev,libxtst-dev,libxt-dev,libcups2-dev,libfontconfig1-dev,libasound2-dev,libfreetype6-dev,libpng-dev,libffi-dev \ --resolve-deps ${ver} /chroots/${arch}_${ver} http://httpredir.debian.org/debian/ configure of jdk: #arch1=aarch64 ; arch2=arm64; gnuname=gnu #arch1=powerpc64le ; arch2=ppc64el; gnuname=gnu #arch1=s390x ; arch2=s390x; gnuname=gnu arch1=mips64el ; arch2=mips64el; gnuname=gnuabi64 apt install g++-${arch1}-linux-${gnuname} gcc-${arch1}-linux-${gnuname} ver=stretch CC=$arch1-linux-${gnuname}-gcc CXX=$arch1-linux-${gnuname}-g++ \ sh ./configure --openjdk-target=$arch1-linux-${gnuname} --with-sysroot=/chroots/${arch2}_${ver}/ --with-toolchain-path=/chroots/${arch2}_${ver}/ \ --with-boot-jdk=/home/loongson/aoqi/jdk-13/ --disable-warnings-as-errors \ --with-jvm-variants=zero \ --x-libraries=/chroots/${arch2}_${ver}/usr/lib/$arch1-linux-${gnuname} --x-include=/chroots/${arch2}_${ver}/usr/include/X11/ \ --with-freetype-lib=/chroots/${arch2}_${ver}/usr/lib/$arch1-linux-${gnuname}/ --with-freetype-include=/chroots/${arch2}_${ver}/usr/include/freetype2 make: do one patch [1] then make images I am trying Magnus's approach. When there are results, I will reply. [1] https://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2018-December/031839.html On Fri, Jan 25, 2019 at 1:19 AM Erik Joelsson <erik.joels...@oracle.com> wrote: > > Hello, > > I agree with the conclusion here, there is certainly a bug in the build > logic. When creating the "Build JDK" during a cross compilation build, > we are, as Magnus said, cutting a few corners for efficiency. One of > those corners is assuming all the java classes are the same and can > simply be reused. It has been shown here that that assumption is not > always correct. > > I think the most reasonable solution is to assume all of java.base needs > to be built specifically for the "Build JDK". I think this can be > reasonably easy to implement (compared to the existing Build JDK logic, > which is arguably rather hairy). > > Magnus' suggested workaround should work fine for now however. > > Filed https://bugs.openjdk.java.net/browse/JDK-8217739 > > /Erik > > On 2019-01-24 05:30, Magnus Ihse Bursie wrote: > > On 2019-01-24 13:22, Leslie Zhai wrote: > >> Hi Magnus, > >> > >> Thanks for your kind response! > >> > >> 在 2019/1/24 下午8:05, Magnus Ihse Bursie 写道: > >>> > >>> > >>> On 2019-01-24 05:45, David Holmes wrote: > >>>> On 24/01/2019 1:51 pm, Ao Qi wrote: > >>>>> Hi David, > >>>>> > >>>>> On Thu, Jan 24, 2019 at 10:47 AM David Holmes > >>>>> <david.hol...@oracle.com> wrote: > >>>>>> > >>>>>> Hi Leslie, > >>>>>> > >>>>>> I'm not Erik :) however .... > >>>>>> > >>>>>> On 24/01/2019 12:28 pm, Leslie Zhai wrote: > >>>>>>> Hi Erik, > >>>>>>> > >>>>>>> Because the flags' macro of MIPS is different from other > >>>>>>> targets[1], it > >>>>>>> will effect the `UnixConstants` of > >>>>>>> src/java.base/unix/classes/sun/nio/fs/UnixConstants.java.template, > >>>>>>> for > >>>>>>> example, PREFIX_O_APPEND, so the `Flags` in `FileChannel` is > >>>>>>> different > >>>>>>> from other targets. Then failed[2] to cross compiling jdk12 for > >>>>>>> mips64el-linux-gnu target by following the document[3]. > >>>>>> > >>>>>> It's been quite a while since we built for a platform where the > >>>>>> flags > >>>>>> had different values, but it is supposed to work. I suspect that > >>>>>> the way > >>>>>> we build now with the module system may not be quite correct in this > >>>>>> regard - but that is just supposition on my part. Because > >>>>>> compile-time > >>>>>> constants are stored directly into class files that use them, we > >>>>>> have to > >>>>>> generate UnixConstants.java before compiling any class that needs > >>>>>> to use > >>>>>> it, then we must compile all classes that do use it. Those > >>>>>> classes must > >>>>>> only be executed in conjunction with a tool executing on the target > >>>>>> platform (javac, jmod etc). My suspicion is that we may be > >>>>>> executing a > >>>>>> tool on the build platform using the newly compiled classes for the > >>>>>> target platform - and that would be wrong. > >>>>>> > >>>>> > >>>>> Yes. Some variables in UnixConstants.java is defined according to the > >>>>> target (fcntl.h of mips in this case), but would be executed on host > >>>>> (x86 in this case) during "make images". These variables of ppc64le, > >>>>> aarch64 and s390x are the same as x86, but the ones of mips are not. > >>>>> However, mips is not an official supported target and I did not find > >>>>> other targets have similar issue, I am not sure if this is a bug > >>>>> or if > >>>>> this is the right mailing list :) > >>>> > >>>> This is the right mailing list to discuss. :) > >>>> > >>>> So I went back to find when this happened in the past and I > >>>> mis-remembered how we solved it. We previously had a problem with > >>>> the Oracle Java SE Embedded PPC port where some Linux PPC-e500v2 > >>>> platforms defined a different value for the O_NOFOLLOW and O_DIRECT > >>>> flags. The solution then was to commit a platform specific version > >>>> of UnixConstants.java and change the build system to only use the > >>>> template file if there was not a pre-existing .java file. But that > >>>> platform and the SE Embedded support was all removed. > >>>> (SocketOptions.java had a similar problem.) Further that build > >>>> logic is completely different to what we had back then (JDK 6/7). > >>>> > >>>> This is definitely a bug in our build logic IMHO as we specifically > >>>> use the build platform c-pre-processor to process the template file > >>>> based on the target header files, but then use the resulting class > >>>> when running tools on the build platform. > >>> I agree with David. This is a bug in the build system; arguably even > >>> a regression. > >>> > >>>> This was not something that happened in 6/7 or even 8 and I think > >>>> the module system tools are where the issue now lies. > >>>> > >>>> I think Erik and/or Magnus will have to give advice on how this may > >>>> be properly fixed. I can't see any simple solution. > >>> Unfortunately, I also agree that there is no simple solution. :-( > >>> > >>> The proper way to handle this is to generate two versions of > >>> UnixConstants and friends, one for the build platform, and one for > >>> the target platform. But as far as I know, there is no simple way to > >>> handle such complications in our current structure. Erik knows more > >>> about this, he was the one who designed the current solution for > >>> handling cross-compilation in the modularized world. > >>> > >>> However, I can at least help you with a relatively simple > >>> workaround. First some background: When we cross-compile, we need > >>> not only a Boot JDK (of version current N-1) running on the build > >>> host platform, but we also need a Build JDK, based on the current > >>> source code, running on the build host. (This is for running > >>> jmod/jlink; it needs to be up to date). If we have no Build JDK > >>> present, we start by creating one ourselves. This is more or less > >>> the same output as running a normal, non-cross compiled, build on > >>> the build host. (But Erik found some ways to cut a few corners to > >>> save time.) Your problem is that the Build JDK is broken, since > >>> UnixConstants has the wrong values. > >>> - > >>> But you can supply your own working Build JDK to configure! > >>> > >>> So, your workflow for cross-compiling to MIPS should be: > >>> 1) create a Build JDK, e.g. like this: "bash configure > >>> --with-conf-name=buildjdk && make jdk CONF=buildjdk" > >>> 2) create your cross-compilation JDK like this: "bash configure > >>> --openjdk-target=mipsel-unknown-linux-gnu > >>> --with-build-jdk=build/buildjdk/jdk" > >>> ... or something like that. > >>> Then you can build your cross-compiled jdk with "make images > >>> CONF=mips". > >> > >> I will try that, thanks a lot for your teaching! > > Please let me know if it works. I wrote the command lines out of my > > head, so they might need some tweaking to get right. > > > > Perhaps this is an acceptable solution to you? Unless Erik can suggest > > ways to fix this properly that is not too complicated, maybe this can > > be a good enough solution for you? (But if there is a simple solution, > > I'd rather have it fixed properly.) > > > > /Magnus > >> > >> Regards, > >> > >> Leslie Zhai > >> > >> > >>> > >>> > >>> In theory, you should rebuild your buildjdk for each and every > >>> change ("make jdk CONF=buildjdk && make images CONF=mips"); but in > >>> reality, I don't believe there is really any need to rebuild the > >>> buildjdk (unless major changes in jlink/jmod happens). > >>> > >>> /Magnus > >>>> > >>>> David > >>>> ----- > >>>> > >>>>> For example: > >>>>> > >>>>> jdk/build$ find . -name UnixConstants.java | xargs grep -A2 O_APPEND > >>>>> ./linux-ppc64le-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-ppc64le-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-ppc64le-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> -- > >>>>> ./linux-x86_64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-x86_64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-x86_64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> -- > >>>>> ./linux-s390x-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-s390x-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-s390x-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> -- > >>>>> ./linux-aarch64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-aarch64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-aarch64-server-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> -- > >>>>> ./linux-x86_64-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-x86_64-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-x86_64-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> -- > >>>>> ./linux-mips64el-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-mips64el-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-mips64el-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 0x0008 > >>>>> -- > >>>>> ./linux-ppc64le-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java: > >>>>> > >>>>> static final int O_APPEND = > >>>>> ./linux-ppc64le-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> ./linux-ppc64le-zero-release/support/gensrc/java.base/sun/nio/fs/UnixConstants.java- > >>>>> > >>>>> 02000 > >>>>> > >>>>> log.mips:2of path: > >>>>> /home/loongson/aoqi/jdk-mips/build/linux-mips64el-normal-server-release/support/interim-jmods/temp/.java.base.jmod.tmp > >>>>> > >>>>> oflags: 769 O_TRUNC:512 O_APPEND:8 O_CREAT:256 O_EXCL:1024 > >>>>> log.ppc:2of path: > >>>>> /home/loongson/aoqi/jdk-mips/build/linux-ppc64le-normal-server-release/support/interim-jmods/temp/.java.base.jmod.tmp > >>>>> > >>>>> oflags: 577 O_TRUNC:512 O_APPEND:1024 O_CREAT:64 O_EXCL:128 > >>>>> > >>>>> Cheers, > >>>>> Ao Qi > >>>>> > >>> > >> > >
