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 >> >>
