Propose to use clang-format to enforce hotspot codestyle

[Ioi Lam]

On 3/11/20 4:19 PM, Volker Simonis wrote:
> Jesper Wilhelmsson <jesper.wilhelmsson at oracle.com> schrieb am Mi., 11. März
> 2020, 19:13:
>
>> As I didn't find one I started to implement my own validator a few years
>> ago. I do have a tool that swallows most of the hotspot code as is, but
>> there are a few issues with macro usages. You see, that is another issue we
>> have to deal with. It's not enough to parse C++. If we want to read and
>> format the code we need to treat our macros as part of the language as
>> well. Hotspot has a few macros that make for real challenges for a parser
>> :-)
>>
> The default Emacs on Ubuntu 18.04 will just hang forever consuming 100% cpu
> when opening globals.hpp with syntax highlighting enabled. :)
>

Really off-topic, but I actually have a patch that overhauls the VM 
flags to get rid of this ridiculous macro. See

http://cr.openjdk.java.net/~iklam/jdk15/vm_flags_overhaul.006/

(Look at globals.hpp, globals.cpp and globals.flags.hpp).

I'll try to post an RFR for this soon ....

Thanks
- Ioi