RFR: 8313592: RISC-V: Link libatomic statically

[Fei Yang]

On Fri, 4 Aug 2023 14:58:08 GMT, Ludovic Henry <luhenry at openjdk.org> wrote:

> > Hello, did you check the license for libatomic.a? Is it compatible with libjvm.so?
> 
> When compiling with gcc or clang (which are AFAIK the only compiler supported for Linux-RISC-V), it uses the compiler's implementation. In the case of GCC, the license is GPL, which is the same as the OpenJDK (GPL with classpath exception). In the case of Clang/LLVM, the license is Apache License 2.0 which is less constraining than GPL.

I think you are talking about the default case, i.e., dynamic linking against libatomic.so.1 for programs built with these two compilers.

I checked the license of both OpenJDK and GNU Atomic Library. For OpenJDK, the GPL version is 2 only. But for libatomic, the version is either GPL version 3, or (at your option) any later version. And it is mentioned on [1] that these two versions are not compatible with each other in our case. So I doubt whether it is legal for both libraries been statically linked against each other. I am not an expert in this area, but I would not suggest we go with this change until this issue is made clear.


[GNU General Public License (GPL) version 3](https://www.gnu.org/licenses/gpl.html) ([#GNUGPL](https://www.gnu.org/licenses/license-list.html#GNUGPL)) ([#GNUGPLv3](https://www.gnu.org/licenses/license-list.html#GNUGPLv3))
This is the latest version of the GNU GPL: a free software license, and a copyleft license. We recommend it for most software packages.

Please note that GPLv3 is not compatible with GPLv2 by itself. However, most software released under GPLv2 allows you to use the terms of later versions of the GPL as well. When this is the case, you can use the code under GPLv3 to make the desired combination. To learn more about compatibility between GNU licenses, please [see our FAQ](https://www.gnu.org/licenses/gpl-faq.html#AllCompatibility).


[1] https://www.gnu.org/licenses/license-list.html

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PR Comment: https://git.openjdk.org/jdk/pull/15119#issuecomment-1666665575