RFR[8u-dev]: 8139040: Fix initializations before ShouldNotReachHere() etc. and enable -Wuninitialized on linux.

[Cheleswer Sahu]

Hi David,

Mattis and I feel it's best to leave the change for "-Wuninitialized " in backport, do you agree with this opinion?

Regards,
Cheleswer


-----Original Message-----
From: Mattis Castegren 
Sent: Wednesday, February 24, 2016 3:45 PM
To: David Holmes; Cheleswer Sahu; hotspot-runtime-dev at openjdk.java.net
Cc: Mattis Castegren
Subject: RE: RFR[8u-dev]: 8139040: Fix initializations before ShouldNotReachHere() etc. and enable -Wuninitialized on linux.

Hi

Regarding: "You can add a check for gcc >= 4.8 when enabling this flag. Although our official compilers are quite old for 8u there may be other community members who use later versions."

If we don't build with this flag in our official builds, I think there is a pretty big risk that we could break things for any OpenJDK engineers who build with 4.8. Adding a new warning flag for those engineers will not give them any benefit, it will only add the risk that they can't build with their gcc version. I suggest we keep the change as it is, and don't include the -Wuninitialized flag on Linux

Kind Regards
/Mattis

-----Original Message-----
From: David Holmes 
Sent: den 23 februari 2016 10:36
To: Cheleswer Sahu; hotspot-runtime-dev at openjdk.java.net
Subject: Re: RFR[8u-dev]: 8139040: Fix initializations before ShouldNotReachHere() etc. and enable -Wuninitialized on linux.

Hi Cheleswer,

On 23/02/2016 7:06 PM, Cheleswer Sahu wrote:
> Could somebody please review the below backport changes.
>
> Hi,
>
> Please review the code changes for backport "https://bugs.openjdk.java.net/browse/JDK-8139040".
>
> JBS link: https://bugs.openjdk.java.net/browse/JDK-8139040
> JDK9 changeset:
> http://hg.openjdk.java.net/jdk9/jdk9/hotspot/rev/825cee2cd7a6
> JDK9 review thread:
> http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2015-Octobe
> r/016005.html
>
> JDK8u webrev: http://cr.openjdk.java.net/~csahu/8139040/

Looks ok.

> List of files not included in this backport:
>      src/share/vm/classfile/compactHashtable.cpp
>      src/share/vm/opto/compile.hpp
>      src/share/vm/opto/superword.cpp
>      src/share/vm/runtime/arguments.cpp
>      Reason: Above file are either not available in JDK8u or changes are not applicable.

Ok.

> make/linux/makefiles/gcc.make
>     Reason: This file contain changes related  "-Wuninitialized" flag which is available since gcc4.8 . JDK8u is supporting lower version of gcc, hence not included this fix.

You can add a check for gcc >= 4.8 when enabling this flag. Although our official compilers are quite old for 8u there may be other community members who use later versions.

Thanks,
David
-----

>
> Regards,
> Cheleswer
>