Thanks , can you push it ( as far as I know someone from Oracle needs to push it because generated-configure.sh is changed ) ?
Best regards, Matthias -----Original Message----- From: Erik Joelsson [mailto:erik.joels...@oracle.com] Sent: Freitag, 14. Juli 2017 14:43 To: Baesken, Matthias <matthias.baes...@sap.com>; Simon Nash <si...@cjnash.com> Cc: 'build-dev@openjdk.java.net' <build-dev@openjdk.java.net>; 'hotspot-...@openjdk.java.net' <hotspot-...@openjdk.java.net>; Zeller, Arno <arno.zel...@sap.com> Subject: Re: RFR: [XS] 8184338 : switch minimum supported gcc version to 4.8 - was : RE: jdk10 build : usage of -fno-var-tracking-assignments g++ flag in hotspot build This looks good to me. /Erik On 2017-07-14 13:47, Baesken, Matthias wrote: > After Simons question , I checked that the jdk10 builds still works with > gcc 4.7 on linux x86_64 as well . > And created a new webrev : > > http://cr.openjdk.java.net/~mbaesken/webrevs/8184338.1/ > > - check adjusted to minimum gcc 4.7 > - common/doc/building.md adjusted (the part talking about gcc versions) > > > Best regards, Matthias > > > > -----Original Message----- > From: Baesken, Matthias > Sent: Freitag, 14. Juli 2017 08:36 > To: 'Simon Nash' <si...@cjnash.com> > Cc: Erik Joelsson <erik.joels...@oracle.com>; 'build-dev@openjdk.java.net' > <build-dev@openjdk.java.net>; 'hotspot-...@openjdk.java.net' > <hotspot-...@openjdk.java.net>; Zeller, Arno <arno.zel...@sap.com> > Subject: RE: RFR: [XS] 8184338 : switch minimum supported gcc version to 4.8 > - was : RE: jdk10 build : usage of -fno-var-tracking-assignments g++ flag in > hotspot build > >> I am currently building JDK 9 for arm32 (hard float and soft float) using >> a Linaro GCC 4.7 cross-compiler (binary download). What is the reason that >> this cannot be supported for JDK 10? > Hi Simon, > reason was that we know gcc-4.8 works nicely because we do a lot of > builds (+tests) with this compiler . > For gcc 4.7 we just do not know ( but for old 4.3 / 4.4 it was obvious that > the current flags do not work any more). > If you are using a gcc compiler < 4.8 only a warning is reported , it does > not mean that you cannot build any more. > > My first suggestion was : > >>>> ( e.g. change to minimum gcc 4.6 or gcc 4.7 supporting the flags used >>>> in the build ) > So if you see a benefit to test for minimum gcc 4.7 and not 4.8 I am fine > with this too (Erik what do you think?). > We at SAP just cannot tell that gcc 4.7 still works (because our builds do > not use it). > > Best regards, Matthias > > > > -----Original Message----- > From: Simon Nash [mailto:si...@cjnash.com] > Sent: Donnerstag, 13. Juli 2017 21:56 > To: Baesken, Matthias <matthias.baes...@sap.com> > Cc: Erik Joelsson <erik.joels...@oracle.com>; 'build-dev@openjdk.java.net' > <build-dev@openjdk.java.net>; 'hotspot-...@openjdk.java.net' > <hotspot-...@openjdk.java.net>; Zeller, Arno <arno.zel...@sap.com> > Subject: Re: RFR: [XS] 8184338 : switch minimum supported gcc version to 4.8 > - was : RE: jdk10 build : usage of -fno-var-tracking-assignments g++ flag in > hotspot build > > I am currently building JDK 9 for arm32 (hard float and soft float) using > a Linaro GCC 4.7 cross-compiler (binary download). What is the reason that > this cannot be supported for JDK 10? > > Best regards, > Simon > > On 13/07/2017 14:40, Baesken, Matthias wrote: >> Hi Erik, I prepared the change : >> >> http://cr.openjdk.java.net/~mbaesken/webrevs/8184338/ >> >> bug : >> >> https://bugs.openjdk.java.net/browse/JDK-8184338 >> >> Asking for review(s) ... >> >> >> Best regards, Matthias >> >> >> >> >> -----Original Message----- >> From: Erik Joelsson [mailto:erik.joels...@oracle.com] >> Sent: Donnerstag, 13. Juli 2017 13:34 >> To: Baesken, Matthias <matthias.baes...@sap.com>; >> 'build-dev@openjdk.java.net' <build-dev@openjdk.java.net>; >> 'hotspot-...@openjdk.java.net' <hotspot-...@openjdk.java.net> >> Subject: Re: jdk10 build : usage of -fno-var-tracking-assignments g++ flag >> in hotspot build >> >> Hello, >> >> That would be the correct place. If you prepare the change and send the >> review I can sponsor the push. >> >> /Erik >> >> On 2017-07-13 13:16, Baesken, Matthias wrote: >>> Hi Erik, >>> >>>> AFAIK, the only reason we support GCC versions older than 4.9 is for you >>>> guys at SAP, so if you would suggest dropping support, that would of >>>> course be the simplest solution. >>> for jdk10 it is fine for us to use minimum gcc 4.8 . That would be >>> probably the most simple solution to avoid running into the >>> "-fno-var-tracking-assignments" issue >>> ( I now and then run into it when I forget to set the PATH to gcc-4.8 >>> one should use for compiling on the SLES11 machine, so I pick up instead >>> the default gcc 4.3.4 from the machine , >>> configure works nicely and then the build fails in the middle of the HS >>> make ) >>> >>> autoconf/toolchain.m4 >>> >>> TOOLCHAIN_MINIMUM_VERSION_gcc="4.8" >>> >>> Is there right place to adjust I think, I guess we need someone for Oracle >>> to regenerate the generated-configure.sh files ? >>> >>> Best regards, Matthias >>> >>> >>> >>> >>> -----Original Message----- >>> From: Erik Joelsson [mailto:erik.joels...@oracle.com] >>> Sent: Donnerstag, 13. Juli 2017 11:59 >>> To: Baesken, Matthias <matthias.baes...@sap.com>; >>> 'build-dev@openjdk.java.net' <build-dev@openjdk.java.net>; >>> 'hotspot-...@openjdk.java.net' <hotspot-...@openjdk.java.net> >>> Subject: Re: jdk10 build : usage of -fno-var-tracking-assignments g++ flag >>> in hotspot build >>> >>> Hello Matthias, >>> >>> AFAIK, the only reason we support GCC versions older than 4.9 is for you >>> guys at SAP, so if you would suggest dropping support, that would of >>> course be the simplest solution. >>> >>> If you want to keep support but make the use of this flag optional, the >>> preferred method is to add a test in flags.m4. We have macros defined >>> for this. FLAGS_COMPILER_CHECK_ARGUMENTS or >>> FLAGS_CXX_COMPILER_CHECK_ARGUMENTS would be suitable in this case. Use >>> it to check if the flag is valid for the current compiler. If so, you >>> can define a variable >>> "CXXFLAGS_GCC_NO_VAR_TRACKING_ASSIGNMENTS=-fno-var-tracking-assignment" >>> and empty otherwise, and in the makefile use this variable in the >>> assignement. >>> >>> We want to avoid static shell expressions in the makefiles if possible >>> and keep that kind of logic in configure. It's also better to explicitly >>> check for features rather than versions. >>> >>> /Erik >>> >>> >>> On 2017-07-13 11:21, Baesken, Matthias wrote: >>>> Hello, when building jdk10 on Suse Linux 11 with default gcc/g++ 4.3.4 >>>> installed, I was running into >>>> compilation errors because of the missing support for g++ flag >>>> -fno-var-tracking-assignments . >>>> >>>> It seems gcc-4.6 has the -fvar-tracking-assignments / >>>> -fnovar-tracking-assignments flags , see >>>> >>>> https://gcc.gnu.org/onlinedocs/gcc-4.6.4/gcc/Option-Summary.html#Option-Summary >>>> >>>> I have no gcc-4.6 at hand but could verify that gcc-4.7 and gcc-4.8 "know" >>>> the flag. >>>> There are various solutions one could do to avoid the compilation error >>>> . >>>> >>>> >>>> 1) disallow usage of old gcc versions here : >>>> >>>> autoconf/toolchain.m4 >>>> >>>> TOOLCHAIN_MINIMUM_VERSION_gcc="4.3" >>>> >>>> ( e.g. change to minimum gcc 4.6 or gcc 4.7 supporting the flags used >>>> in the build ) >>>> >>>> >>>> 2) remove the flag -fno-var-tracking-assignments for older gcc versions >>>> here : >>>> (in a similar way it was done : >>>> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/37e693211deb ) >>>> >>>> hotspot/make/lib/JvmOverrideFiles.gmk-32-ifeq ($(TOOLCHAIN_TYPE), gcc) >>>> hotspot/make/lib/JvmOverrideFiles.gmk:33: >>>> BUILD_LIBJVM_vmStructs.cpp_CXXFLAGS := -fno-var-tracking-assignments -O0 >>>> hotspot/make/lib/JvmOverrideFiles.gmk:34: >>>> BUILD_LIBJVM_jvmciCompilerToVM.cpp_CXXFLAGS := >>>> -fno-var-tracking-assignments >>>> hotspot/make/lib/JvmOverrideFiles.gmk-35-endif >>>> >>>> What is your preferred solution ? >>>> >>>> >>>> Thanks, Matthias >>>> >>>>
