Hi Volker,
On 20/05/2015 7:50 PM, Volker Simonis wrote:
Hi,
I'm a little confused about this change. I finally found some time to
look at it, because it makes most of our nightly jdk9/dev builds fail.
Now I've looked at the 'simplest possible failure' which happens on
linux/amd64. The failure is the following:
/net/usr.work/openjdk/nb/linuxx86_64/nightly/jdk9/jdk/src/java.base/share/native/libjava/jdk_util.c:79:5:
error: comparison of unsigned expression >= 0 is always true
[-Werror=type-limits]
First I thought this is because we are using a different version of
GCC but I've just verified that this warning which is now turned into
an error happens with all version of GCC starting from at least 4.3 up
to 4.8.
So do you do your regular builds on linux/amd64 by default with
"--disable-warnings-as-errors" now?
In jdk/make/lib/CoreLibraries.gmk there should be this fragment:
$(eval $(call SetupNativeCompilation,BUILD_LIBJAVA, \
LIBRARY := java, \
OUTPUT_DIR := $(INSTALL_LIBRARIES_HERE), \
SRC := $(LIBJAVA_SRC_DIRS), \
OPTIMIZATION := HIGH, \
CFLAGS := $(CFLAGS_JDKLIB) \
$(LIBJAVA_CFLAGS), \
DISABLED_WARNINGS_gcc := type-limits format-nonliteral, \
which disables the warning you are seeing.
David
-----
Reading you first mail, the code should compile fine on the build
systems used internally at Oracle and according to
https://wiki.openjdk.java.net/display/Build/Supported+Build+Platforms
they should use gcc 4.8.2.
So what's the problem here or am I doing something wrong?
Thank you and best regards,
Volker
On Sat, May 9, 2015 at 6:30 AM, Tim Bell <tim.b...@oracle.com> wrote:
Magnus:
Looks good to me as well.
Tim
On 05/08/15 01:32, Erik Joelsson wrote:
Looks good.
/Erik
On 2015-05-08 09:57, Magnus Ihse Bursie wrote:
On 2015-04-20 09:02, Erik Joelsson wrote:
Looks good to me.
Thanks Erik.
Unfortunately, I never got round to pushing this. In the meantime, the
codebase evolved, and I had to add a couple of more disabled warnings. I
also modified the help text on a failed build slightly.
Here's the updated webrev:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors/webrev.01
/Magnus
/Erik
On 2015-04-17 14:52, Magnus Ihse Bursie wrote:
With JDK-8074096, the number of warnings in the product was reduced to
a minimum. This enables the next step, which is turning on the respective
compiler flags that turns warnings into errors. In the long run, this is the
only way to keep the warnings from creeping back.
Even with JDK-8074096, the product does not build 100% warning free.
This is due to some warnings that cannot be disabled, or (in one case) where
C and C++ code is mixed, and warnings for both languages cannot be used. A
system similar to the one introduced in JDK-8074096 is therefore needed, in
which individual libraries can be exempted from this flag, until such
warnings are fixed. A library can thus disable warnings as errors with
WARNINGS_AS_ERRORS := false, or (better) use a toolchain-specific version,
e.g WARNINGS_AS_ERRORS_gcc := false. This is intended as a temporary
measure, though. The long-term solution is reasonably to fix the warnings
and remove that argument.
Also, different versions of compilers can generate a different set of
warnings. It is therefore necessary to be able to turn off this globally.
Therefor a new flag for configure is introduced:
--disable-warnings-as-errors.
While the code compiles without errors on the build systems used
internally at Oracle, this might not be the case on other combinations of
operating system versions and toolchain versions. To facilitate for
unexpecting developers, a help message is added if the build fails, that
suggests using --disable-warnings-as-errors. This solution was chosen as a
compromise between the "hard core" solution of turning on warnings as errors
by default for anyone, and the cowar... erm, conservative solution of
checking if the compiler versions exactly match what's used inside Oracle
(and therefore regularly tested), and only turn it on in that case.
Similarly to JDK-8074096, I intend to file follow-up bugs for each
individual library that got a WARNINGS_AS_ERRORS_* := false.
Bug: https://bugs.openjdk.java.net/browse/JDK-8074859
WebRev for top:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors-top/webrev.01
WebRev for jdk:
http://cr.openjdk.java.net/~ihse/JDK-8074859-warnings-as-errors-jdk/webrev.01
Some comments:
* I needed to add a few more DISABLED_WARNINGS. For windows, this is
most likely due to the recent compiler change. For other libraries, I'm not
sure, but it might well be the result of recent changes that has introduced
new warnings. If so, it highlights the need of this patch to keep the build
warning free.
* For a few libraries and toolchains, there is *both*
WARNINGS_AS_ERRORS := false and a DISABLED_WARNINGS list. This is the case
if not all warnings are possible to disable.
* I have removed some incorrect uses of SHARED_LIBRARY_FLAGS. This is
included in our JDK LDFLAGS, so it should not be set separately, and
definitely not as CFLAGS. (This caused compiler warnings, which now turned
into errors.) However, a more suitable long-term solution is probably to
move the knowledge of how to create shared libraries more specifically into
SetupNativeCompilation, and not set it as part of the JDK flags.
/Magnus
