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
